use strict;
use warnings;
+use base qw/DBIx::Class/;
+use DBIx::Class::Carp;
+use DBIx::Class::ResultSetColumn;
+use Scalar::Util qw/blessed weaken reftype/;
+use Try::Tiny;
+use Data::Compare (); # no imports!!! guard against insane architecture
+
+# not importing first() as it will clash with our own method
+use List::Util ();
+
+BEGIN {
+ # De-duplication in _merge_attr() is disabled, but left in for reference
+ # (the merger is used for other things that ought not to be de-duped)
+ *__HM_DEDUP = sub () { 0 };
+}
+
+use namespace::clean;
+
use overload
'0+' => "count",
'bool' => "_bool",
fallback => 1;
-use Carp::Clan qw/^DBIx::Class/;
-use DBIx::Class::Exception;
-use Data::Page;
-use Storable;
-use DBIx::Class::ResultSetColumn;
-use DBIx::Class::ResultSourceHandle;
-use List::Util ();
-use Scalar::Util ();
-use base qw/DBIx::Class/;
-
-#use Test::Deep::NoTest (qw/eq_deeply/);
-use Data::Dumper::Concise;
+# this is real - CDBICompat overrides it with insanity
+# yes, prototype won't matter, but that's for now ;)
+sub _bool () { 1 }
-__PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
+__PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
=head1 NAME
=head1 SYNOPSIS
- my $users_rs = $schema->resultset('User');
- my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
+ my $users_rs = $schema->resultset('User');
+ while( $user = $users_rs->next) {
+ print $user->username;
+ }
+
+ my $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
=head1 DESCRIPTION
The query that the ResultSet represents is B<only> executed against
the database when these methods are called:
-L</find> L</next> L</all> L</first> L</single> L</count>
+L</find>, L</next>, L</all>, L</first>, L</single>, L</count>.
+
+If a resultset is used in a numeric context it returns the L</count>.
+However, if it is used in a boolean context it is B<always> true. So if
+you want to check if a resultset has any results, you must use C<if $rs
+!= 0>.
+
+=head1 CUSTOM ResultSet CLASSES THAT USE Moose
+
+If you want to make your custom ResultSet classes with L<Moose>, use a template
+similar to:
+
+ package MyApp::Schema::ResultSet::User;
+
+ use Moose;
+ use namespace::autoclean;
+ use MooseX::NonMoose;
+ extends 'DBIx::Class::ResultSet';
+
+ sub BUILDARGS { $_[2] }
+
+ ...your code...
+
+ __PACKAGE__->meta->make_immutable;
+
+ 1;
+
+The L<MooseX::NonMoose> is necessary so that the L<Moose> constructor does not
+clash with the regular ResultSet constructor. Alternatively, you can use:
+
+ __PACKAGE__->meta->make_immutable(inline_constructor => 0);
+
+The L<BUILDARGS|Moose::Manual::Construction/BUILDARGS> is necessary because the
+signature of the ResultSet C<new> is C<< ->new($source, \%args) >>.
=head1 EXAMPLES
sub get_data {
my $self = shift;
my $request = $self->get_request; # Get a request object somehow.
- my $schema = $self->get_schema; # Get the DBIC schema object somehow.
+ my $schema = $self->result_source->schema;
my $cd_rs = $schema->resultset('CD')->search({
title => $request->param('title'),
year => $request->param('year'),
});
- $self->apply_security_policy( $cd_rs );
+ $cd_rs = $self->apply_security_policy( $cd_rs );
return $cd_rs->all();
}
=head3 Resolving conditions and attributes
-When a resultset is chained from another resultset, conditions and
-attributes with the same keys need resolving.
+When a resultset is chained from another resultset (ie:
+C<my $new_rs = $old_rs->search(\%extra_cond, \%attrs)>), conditions
+and attributes with the same keys need resolving.
-L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
-into the existing ones from the original resultset.
+If any of L</columns>, L</select>, L</as> are present, they reset the
+original selection, and start the selection "clean".
-The L</where>, L</having> attribute, and any search conditions are
+The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
+are merged into the existing ones from the original resultset.
+
+The L</where> and L</having> attributes, and any search conditions, are
merged with an SQL C<AND> to the existing condition from the original
resultset.
See: L</search>, L</count>, L</get_column>, L</all>, L</create>.
-=head1 OVERLOADING
-
-If a resultset is used in a numeric context it returns the L</count>.
-However, if it is used in a boolean context it is always true. So if
-you want to check if a resultset has any results use C<if $rs != 0>.
-C<if $rs> will always be true.
-
=head1 METHODS
=head2 new
=over 4
-=item Arguments: $source, \%$attrs
+=item Arguments: L<$source|DBIx::Class::ResultSource>, L<\%attrs?|/ATTRIBUTES>
-=item Return Value: $rs
+=item Return Value: L<$resultset|/search>
=back
L</ATTRIBUTES> below). Does not perform any queries -- these are
executed as needed by the other methods.
-Generally you won't need to construct a resultset manually. You'll
-automatically get one from e.g. a L</search> called in scalar context:
+Generally you never construct a resultset manually. Instead you get one
+from e.g. a
+C<< $schema->L<resultset|DBIx::Class::Schema/resultset>('$source_name') >>
+or C<< $another_resultset->L<search|/search>(...) >> (the later called in
+scalar context):
my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
-IMPORTANT: If called on an object, proxies to new_result instead so
+=over
+
+=item WARNING
+
+If called on an object, proxies to L</new_result> instead, so
my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
-will return a CD object, not a ResultSet.
+will return a CD object, not a ResultSet, and is equivalent to:
+
+ my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });
+
+Please also keep in mind that many internals call L</new_result> directly,
+so overloading this method with the idea of intercepting new result object
+creation B<will not work>. See also warning pertaining to L</create>.
+
+=back
=cut
return $class->new_result(@_) if ref $class;
my ($source, $attrs) = @_;
- $source = $source->handle
- unless $source->isa('DBIx::Class::ResultSourceHandle');
+ $source = $source->resolve
+ if $source->isa('DBIx::Class::ResultSourceHandle');
+
$attrs = { %{$attrs||{}} };
+ delete @{$attrs}{qw(_sqlmaker_select_args _related_results_construction)};
if ($attrs->{page}) {
$attrs->{rows} ||= 10;
$attrs->{alias} ||= 'me';
- # Creation of {} and bless separated to mitigate RH perl bug
- # see https://bugzilla.redhat.com/show_bug.cgi?id=196836
- my $self = {
- _source_handle => $source,
+ my $self = bless {
+ result_source => $source,
cond => $attrs->{where},
- count => undef,
pager => undef,
- attrs => $attrs
- };
+ attrs => $attrs,
+ }, $class;
- bless $self, $class;
+ # if there is a dark selector, this means we are already in a
+ # chain and the cleanup/sanification was taken care of by
+ # _search_rs already
+ $self->_normalize_selection($attrs)
+ unless $attrs->{_dark_selector};
$self->result_class(
- $attrs->{result_class} || $source->resolve->result_class
+ $attrs->{result_class} || $source->result_class
);
- return $self;
+ $self;
}
=head2 search
=over 4
-=item Arguments: $cond, \%attrs?
+=item Arguments: L<$cond|DBIx::Class::SQLMaker> | undef, L<\%attrs?|/ATTRIBUTES>
-=item Return Value: $resultset (scalar context), @row_objs (list context)
+=item Return Value: $resultset (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
=back
my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]);
# year = 2005 OR year = 2004
+In list context, C<< ->all() >> is called implicitly on the resultset, thus
+returning a list of L<result|DBIx::Class::Manual::ResultClass> objects instead.
+To avoid that, use L</search_rs>.
+
If you need to pass in additional attributes but no additional condition,
call it as C<search(undef, \%attrs)>.
For a list of attributes that can be passed to C<search>, see
L</ATTRIBUTES>. For more examples of using this function, see
L<Searching|DBIx::Class::Manual::Cookbook/Searching>. For a complete
-documentation for the first argument, see L<SQL::Abstract>.
+documentation for the first argument, see L<SQL::Abstract/"WHERE CLAUSES">
+and its extension L<DBIx::Class::SQLMaker>.
For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
+=head3 CAVEAT
+
+Note that L</search> does not process/deflate any of the values passed in the
+L<SQL::Abstract>-compatible search condition structure. This is unlike other
+condition-bound methods L</new_result>, L</create> and L</find>. The user must ensure
+manually that any value passed to this method will stringify to something the
+RDBMS knows how to deal with. A notable example is the handling of L<DateTime>
+objects, for more info see:
+L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
+
=cut
sub search {
my $self = shift;
my $rs = $self->search_rs( @_ );
- return (wantarray ? $rs->all : $rs);
+
+ if (wantarray) {
+ return $rs->all;
+ }
+ elsif (defined wantarray) {
+ return $rs;
+ }
+ else {
+ # we can be called by a relationship helper, which in
+ # turn may be called in void context due to some braindead
+ # overload or whatever else the user decided to be clever
+ # at this particular day. Thus limit the exception to
+ # external code calls only
+ $self->throw_exception ('->search is *not* a mutator, calling it in void context makes no sense')
+ if (caller)[0] !~ /^\QDBIx::Class::/;
+
+ return ();
+ }
}
=head2 search_rs
=over 4
-=item Arguments: $cond, \%attrs?
+=item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
-=item Return Value: $resultset
+=item Return Value: L<$resultset|/search>
=back
sub search_rs {
my $self = shift;
- # Special-case handling for (undef, undef).
- if ( @_ == 2 && !defined $_[1] && !defined $_[0] ) {
- pop(@_); pop(@_);
- }
+ my $rsrc = $self->result_source;
+ my ($call_cond, $call_attrs);
+
+ # Special-case handling for (undef, undef) or (undef)
+ # Note that (foo => undef) is valid deprecated syntax
+ @_ = () if not scalar grep { defined $_ } @_;
- my $attrs = {};
- $attrs = pop(@_) if @_ > 1 and ref $_[$#_] eq 'HASH';
- my $our_attrs = { %{$self->{attrs}} };
- my $having = delete $our_attrs->{having};
- my $where = delete $our_attrs->{where};
+ # just a cond
+ if (@_ == 1) {
+ $call_cond = shift;
+ }
+ # fish out attrs in the ($condref, $attr) case
+ elsif (@_ == 2 and ( ! defined $_[0] or (ref $_[0]) ne '') ) {
+ ($call_cond, $call_attrs) = @_;
+ }
+ elsif (@_ % 2) {
+ $self->throw_exception('Odd number of arguments to search')
+ }
+ # legacy search
+ elsif (@_) {
+ carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead'
+ unless $rsrc->result_class->isa('DBIx::Class::CDBICompat');
+
+ for my $i (0 .. $#_) {
+ next if $i % 2;
+ $self->throw_exception ('All keys in condition key/value pairs must be plain scalars')
+ if (! defined $_[$i] or ref $_[$i] ne '');
+ }
- my $rows;
+ $call_cond = { @_ };
+ }
+ # see if we can keep the cache (no $rs changes)
+ my $cache;
my %safe = (alias => 1, cache => 1);
+ if ( ! List::Util::first { !$safe{$_} } keys %$call_attrs and (
+ ! defined $call_cond
+ or
+ ref $call_cond eq 'HASH' && ! keys %$call_cond
+ or
+ ref $call_cond eq 'ARRAY' && ! @$call_cond
+ )) {
+ $cache = $self->get_cache;
+ }
- unless (
- (@_ && defined($_[0])) # @_ == () or (undef)
- ||
- (keys %$attrs # empty attrs or only 'safe' attrs
- && List::Util::first { !$safe{$_} } keys %$attrs)
- ) {
- # no search, effectively just a clone
- $rows = $self->get_cache;
- }
-
- # reset the selector list
- if (List::Util::first { exists $attrs->{$_} } qw{columns select as}) {
- delete @{$our_attrs}{qw{select as columns +select +as +columns include_columns}};
- }
-
- my $new_attrs = { %{$our_attrs}, %{$attrs} };
-
- # merge new attrs into inherited
- foreach my $key (qw/join prefetch +select +as +columns include_columns bind/) {
- next unless exists $attrs->{$key};
- $new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
- }
-
- my $cond = (@_
- ? (
- (@_ == 1 || ref $_[0] eq "HASH")
- ? (
- (ref $_[0] eq 'HASH')
- ? (
- (keys %{ $_[0] } > 0)
- ? shift
- : undef
- )
- : shift
- )
- : (
- (@_ % 2)
- ? $self->throw_exception("Odd number of arguments to search")
- : {@_}
- )
- )
- : undef
- );
+ my $old_attrs = { %{$self->{attrs}} };
+ my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
- if (defined $where) {
- $new_attrs->{where} = (
- defined $new_attrs->{where}
- ? { '-and' => [
- map {
- ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
- } $where, $new_attrs->{where}
- ]
- }
- : $where);
+ my $new_attrs = { %$old_attrs };
+
+ # take care of call attrs (only if anything is changing)
+ if ($call_attrs and keys %$call_attrs) {
+
+ # copy for _normalize_selection
+ $call_attrs = { %$call_attrs };
+
+ my @selector_attrs = qw/select as columns cols +select +as +columns include_columns/;
+
+ # reset the current selector list if new selectors are supplied
+ if (List::Util::first { exists $call_attrs->{$_} } qw/columns cols select as/) {
+ delete @{$old_attrs}{(@selector_attrs, '_dark_selector')};
+ }
+
+ # Normalize the new selector list (operates on the passed-in attr structure)
+ # Need to do it on every chain instead of only once on _resolved_attrs, in
+ # order to allow detection of empty vs partial 'as'
+ $call_attrs->{_dark_selector} = $old_attrs->{_dark_selector}
+ if $old_attrs->{_dark_selector};
+ $self->_normalize_selection ($call_attrs);
+
+ # start with blind overwriting merge, exclude selector attrs
+ $new_attrs = { %{$old_attrs}, %{$call_attrs} };
+ delete @{$new_attrs}{@selector_attrs};
+
+ for (@selector_attrs) {
+ $new_attrs->{$_} = $self->_merge_attr($old_attrs->{$_}, $call_attrs->{$_})
+ if ( exists $old_attrs->{$_} or exists $call_attrs->{$_} );
+ }
+
+ # older deprecated name, use only if {columns} is not there
+ if (my $c = delete $new_attrs->{cols}) {
+ carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
+ if ($new_attrs->{columns}) {
+ carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
+ }
+ else {
+ $new_attrs->{columns} = $c;
+ }
+ }
+
+
+ # join/prefetch use their own crazy merging heuristics
+ foreach my $key (qw/join prefetch/) {
+ $new_attrs->{$key} = $self->_merge_joinpref_attr($old_attrs->{$key}, $call_attrs->{$key})
+ if exists $call_attrs->{$key};
+ }
+
+ # stack binds together
+ $new_attrs->{bind} = [ @{ $old_attrs->{bind} || [] }, @{ $call_attrs->{bind} || [] } ];
}
- if (defined $cond) {
- $new_attrs->{where} = (
- defined $new_attrs->{where}
- ? { '-and' => [
- map {
- ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
- } $cond, $new_attrs->{where}
- ]
- }
- : $cond);
+
+ for ($old_where, $call_cond) {
+ if (defined $_) {
+ $new_attrs->{where} = $self->_stack_cond (
+ $_, $new_attrs->{where}
+ );
+ }
}
- if (defined $having) {
- $new_attrs->{having} = (
- defined $new_attrs->{having}
- ? { '-and' => [
- map {
- ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_
- } $having, $new_attrs->{having}
- ]
- }
- : $having);
+ if (defined $old_having) {
+ $new_attrs->{having} = $self->_stack_cond (
+ $old_having, $new_attrs->{having}
+ )
}
- my $rs = (ref $self)->new($self->result_source, $new_attrs);
+ my $rs = (ref $self)->new($rsrc, $new_attrs);
- $rs->set_cache($rows) if ($rows);
+ $rs->set_cache($cache) if ($cache);
return $rs;
}
+my $dark_sel_dumper;
+sub _normalize_selection {
+ my ($self, $attrs) = @_;
+
+ # legacy syntax
+ if ( exists $attrs->{include_columns} ) {
+ carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
+ $attrs->{'+columns'} = $self->_merge_attr(
+ $attrs->{'+columns'}, delete $attrs->{include_columns}
+ );
+ }
+
+ # columns are always placed first, however
+
+ # Keep the X vs +X separation until _resolved_attrs time - this allows to
+ # delay the decision on whether to use a default select list ($rsrc->columns)
+ # allowing stuff like the remove_columns helper to work
+ #
+ # select/as +select/+as pairs need special handling - the amount of select/as
+ # elements in each pair does *not* have to be equal (think multicolumn
+ # selectors like distinct(foo, bar) ). If the selector is bare (no 'as'
+ # supplied at all) - try to infer the alias, either from the -as parameter
+ # of the selector spec, or use the parameter whole if it looks like a column
+ # name (ugly legacy heuristic). If all fails - leave the selector bare (which
+ # is ok as well), but make sure no more additions to the 'as' chain take place
+ for my $pref ('', '+') {
+
+ my ($sel, $as) = map {
+ my $key = "${pref}${_}";
+
+ my $val = [ ref $attrs->{$key} eq 'ARRAY'
+ ? @{$attrs->{$key}}
+ : $attrs->{$key} || ()
+ ];
+ delete $attrs->{$key};
+ $val;
+ } qw/select as/;
+
+ if (! @$as and ! @$sel ) {
+ next;
+ }
+ elsif (@$as and ! @$sel) {
+ $self->throw_exception(
+ "Unable to handle ${pref}as specification (@$as) without a corresponding ${pref}select"
+ );
+ }
+ elsif( ! @$as ) {
+ # no as part supplied at all - try to deduce (unless explicit end of named selection is declared)
+ # if any @$as has been supplied we assume the user knows what (s)he is doing
+ # and blindly keep stacking up pieces
+ unless ($attrs->{_dark_selector}) {
+ SELECTOR:
+ for (@$sel) {
+ if ( ref $_ eq 'HASH' and exists $_->{-as} ) {
+ push @$as, $_->{-as};
+ }
+ # assume any plain no-space, no-parenthesis string to be a column spec
+ # FIXME - this is retarded but is necessary to support shit like 'count(foo)'
+ elsif ( ! ref $_ and $_ =~ /^ [^\s\(\)]+ $/x) {
+ push @$as, $_;
+ }
+ # if all else fails - raise a flag that no more aliasing will be allowed
+ else {
+ $attrs->{_dark_selector} = {
+ plus_stage => $pref,
+ string => ($dark_sel_dumper ||= do {
+ require Data::Dumper::Concise;
+ Data::Dumper::Concise::DumperObject()->Indent(0);
+ })->Values([$_])->Dump
+ ,
+ };
+ last SELECTOR;
+ }
+ }
+ }
+ }
+ elsif (@$as < @$sel) {
+ $self->throw_exception(
+ "Unable to handle an ${pref}as specification (@$as) with less elements than the corresponding ${pref}select"
+ );
+ }
+ elsif ($pref and $attrs->{_dark_selector}) {
+ $self->throw_exception(
+ "Unable to process named '+select', resultset contains an unnamed selector $attrs->{_dark_selector}{string}"
+ );
+ }
+
+
+ # merge result
+ $attrs->{"${pref}select"} = $self->_merge_attr($attrs->{"${pref}select"}, $sel);
+ $attrs->{"${pref}as"} = $self->_merge_attr($attrs->{"${pref}as"}, $as);
+ }
+}
+
+sub _stack_cond {
+ my ($self, $left, $right) = @_;
+
+ # collapse single element top-level conditions
+ # (single pass only, unlikely to need recursion)
+ for ($left, $right) {
+ if (ref $_ eq 'ARRAY') {
+ if (@$_ == 0) {
+ $_ = undef;
+ }
+ elsif (@$_ == 1) {
+ $_ = $_->[0];
+ }
+ }
+ elsif (ref $_ eq 'HASH') {
+ my ($first, $more) = keys %$_;
+
+ # empty hash
+ if (! defined $first) {
+ $_ = undef;
+ }
+ # one element hash
+ elsif (! defined $more) {
+ if ($first eq '-and' and ref $_->{'-and'} eq 'HASH') {
+ $_ = $_->{'-and'};
+ }
+ elsif ($first eq '-or' and ref $_->{'-or'} eq 'ARRAY') {
+ $_ = $_->{'-or'};
+ }
+ }
+ }
+ }
+
+ # merge hashes with weeding out of duplicates (simple cases only)
+ if (ref $left eq 'HASH' and ref $right eq 'HASH') {
+
+ # shallow copy to destroy
+ $right = { %$right };
+ for (grep { exists $right->{$_} } keys %$left) {
+ # the use of eq_deeply here is justified - the rhs of an
+ # expression can contain a lot of twisted weird stuff
+ delete $right->{$_} if Data::Compare::Compare( $left->{$_}, $right->{$_} );
+ }
+
+ $right = undef unless keys %$right;
+ }
+
+
+ if (defined $left xor defined $right) {
+ return defined $left ? $left : $right;
+ }
+ elsif (! defined $left) {
+ return undef;
+ }
+ else {
+ return { -and => [ $left, $right ] };
+ }
+}
+
=head2 search_literal
+B<CAVEAT>: C<search_literal> is provided for Class::DBI compatibility and
+should only be used in that context. C<search_literal> is a convenience
+method. It is equivalent to calling C<< $schema->search(\[]) >>, but if you
+want to ensure columns are bound correctly, use L</search>.
+
+See L<DBIx::Class::Manual::Cookbook/Searching> and
+L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
+require C<search_literal>.
+
=over 4
-=item Arguments: $sql_fragment, @bind_values
+=item Arguments: $sql_fragment, @standalone_bind_values
-=item Return Value: $resultset (scalar context), @row_objs (list context)
+=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
=back
Pass a literal chunk of SQL to be added to the conditional part of the
resultset query.
-CAVEAT: C<search_literal> is provided for Class::DBI compatibility and should
-only be used in that context. C<search_literal> is a convenience method.
-It is equivalent to calling $schema->search(\[]), but if you want to ensure
-columns are bound correctly, use C<search>.
-
Example of how to use C<search> instead of C<search_literal>
my @cds = $cd_rs->search_literal('cdid = ? AND (artist = ? OR artist = ?)', (2, 1, 2));
my @cds = $cd_rs->search(\[ 'cdid = ? AND (artist = ? OR artist = ?)', [ 'cdid', 2 ], [ 'artist', 1 ], [ 'artist', 2 ] ]);
-
-See L<DBIx::Class::Manual::Cookbook/Searching> and
-L<DBIx::Class::Manual::FAQ/Searching> for searching techniques that do not
-require C<search_literal>.
-
=cut
sub search_literal {
if ( @bind && ref($bind[-1]) eq 'HASH' ) {
$attr = pop @bind;
}
- return $self->search(\[ $sql, map [ __DUMMY__ => $_ ], @bind ], ($attr || () ));
+ return $self->search(\[ $sql, map [ {} => $_ ], @bind ], ($attr || () ));
}
=head2 find
=over 4
-=item Arguments: @values | \%cols, \%attrs?
+=item Arguments: \%columns_values | @pk_values, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
-=item Return Value: $row_object | undef
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
=back
-Finds a row based on its primary key or unique constraint. For example, to find
-a row by its primary key:
+Finds and returns a single row based on supplied criteria. Takes either a
+hashref with the same format as L</create> (including inference of foreign
+keys from related objects), or a list of primary key values in the same
+order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
+declaration on the L</result_source>.
+
+In either case an attempt is made to combine conditions already existing on
+the resultset with the condition passed to this method.
+
+To aid with preparing the correct query for the storage you may supply the
+C<key> attribute, which is the name of a
+L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
+unique constraint corresponding to the
+L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
+C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
+to construct a query that satisfies the named unique constraint fully (
+non-NULL values for each column member of the constraint) an exception is
+thrown.
+
+If no C<key> is specified, the search is carried over all unique constraints
+which are fully defined by the available condition.
+
+If no such constraint is found, C<find> currently defaults to a simple
+C<< search->(\%column_values) >> which may or may not do what you expect.
+Note that this fallback behavior may be deprecated in further versions. If
+you need to search with arbitrary conditions - use L</search>. If the query
+resulting from this fallback produces more than one row, a warning to the
+effect is issued, though only the first row is constructed and returned as
+C<$result_object>.
- my $cd = $schema->resultset('CD')->find(5);
+In addition to C<key>, L</find> recognizes and applies standard
+L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
-You can also find a row by a specific unique constraint using the C<key>
-attribute. For example:
+Note that if you have extra concerns about the correctness of the resulting
+query you need to specify the C<key> attribute and supply the entire condition
+as an argument to find (since it is not always possible to perform the
+combination of the resultset condition with the supplied one, especially if
+the resultset condition contains literal sql).
- my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', {
- key => 'cd_artist_title'
- });
+For example, to find a row by its primary key:
+
+ my $cd = $schema->resultset('CD')->find(5);
-Additionally, you can specify the columns explicitly by name:
+You can also find a row by a specific unique constraint:
my $cd = $schema->resultset('CD')->find(
{
{ key => 'cd_artist_title' }
);
-If the C<key> is specified as C<primary>, it searches only on the primary key.
-
-If no C<key> is specified, it searches on all unique constraints defined on the
-source for which column data is provided, including the primary key.
-
-If your table does not have a primary key, you B<must> provide a value for the
-C<key> attribute matching one of the unique constraints on the source.
-
-In addition to C<key>, L</find> recognizes and applies standard
-L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
-
-Note: If your query does not return only one row, a warning is generated:
-
- Query returned more than one row
-
-See also L</find_or_create> and L</update_or_create>. For information on how to
-declare unique constraints, see
-L<DBIx::Class::ResultSource/add_unique_constraint>.
+See also L</find_or_create> and L</update_or_create>.
=cut
my $self = shift;
my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
- # Default to the primary key, but allow a specific key
- my @cols = exists $attrs->{key}
- ? $self->result_source->unique_constraint_columns($attrs->{key})
- : $self->result_source->primary_columns;
- $self->throw_exception(
- "Can't find unless a primary key is defined or unique constraint is specified"
- ) unless @cols;
+ my $rsrc = $self->result_source;
- # Parse out a hashref from input
- my $input_query;
- if (ref $_[0] eq 'HASH') {
- $input_query = { %{$_[0]} };
+ my $constraint_name;
+ if (exists $attrs->{key}) {
+ $constraint_name = defined $attrs->{key}
+ ? $attrs->{key}
+ : $self->throw_exception("An undefined 'key' resultset attribute makes no sense")
+ ;
}
- elsif (@_ == @cols) {
- $input_query = {};
- @{$input_query}{@cols} = @_;
+
+ # Parse out the condition from input
+ my $call_cond;
+
+ if (ref $_[0] eq 'HASH') {
+ $call_cond = { %{$_[0]} };
}
else {
- # Compatibility: Allow e.g. find(id => $value)
- carp "Find by key => value deprecated; please use a hashref instead";
- $input_query = {@_};
- }
-
- my (%related, $info);
-
- KEY: foreach my $key (keys %$input_query) {
- if (ref($input_query->{$key})
- && ($info = $self->result_source->relationship_info($key))) {
- my $val = delete $input_query->{$key};
- next KEY if (ref($val) eq 'ARRAY'); # has_many for multi_create
- my $rel_q = $self->result_source->_resolve_condition(
- $info->{cond}, $val, $key
- );
- die "Can't handle OR join condition in find" if ref($rel_q) eq 'ARRAY';
+ # if only values are supplied we need to default to 'primary'
+ $constraint_name = 'primary' unless defined $constraint_name;
+
+ my @c_cols = $rsrc->unique_constraint_columns($constraint_name);
+
+ $self->throw_exception(
+ "No constraint columns, maybe a malformed '$constraint_name' constraint?"
+ ) unless @c_cols;
+
+ $self->throw_exception (
+ 'find() expects either a column/value hashref, or a list of values '
+ . "corresponding to the columns of the specified unique constraint '$constraint_name'"
+ ) unless @c_cols == @_;
+
+ $call_cond = {};
+ @{$call_cond}{@c_cols} = @_;
+ }
+
+ my %related;
+ for my $key (keys %$call_cond) {
+ if (
+ my $keyref = ref($call_cond->{$key})
+ and
+ my $relinfo = $rsrc->relationship_info($key)
+ ) {
+ my $val = delete $call_cond->{$key};
+
+ next if $keyref eq 'ARRAY'; # has_many for multi_create
+
+ my $rel_q = $rsrc->_resolve_condition(
+ $relinfo->{cond}, $val, $key, $key
+ );
+ die "Can't handle complex relationship conditions in find" if ref($rel_q) ne 'HASH';
@related{keys %$rel_q} = values %$rel_q;
}
}
- if (my @keys = keys %related) {
- @{$input_query}{@keys} = values %related;
- }
+ # relationship conditions take precedence (?)
+ @{$call_cond}{keys %related} = values %related;
- # Build the final query: Default to the disjunction of the unique queries,
- # but allow the input query in case the ResultSet defines the query or the
- # user is abusing find
my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
- my $query;
- if (exists $attrs->{key}) {
- my @unique_cols = $self->result_source->unique_constraint_columns($attrs->{key});
- my $unique_query = $self->_build_unique_query($input_query, \@unique_cols);
- $query = $self->_add_alias($unique_query, $alias);
+ my $final_cond;
+ if (defined $constraint_name) {
+ $final_cond = $self->_qualify_cond_columns (
+
+ $self->_build_unique_cond (
+ $constraint_name,
+ $call_cond,
+ ),
+
+ $alias,
+ );
}
elsif ($self->{attrs}{accessor} and $self->{attrs}{accessor} eq 'single') {
# This means that we got here after a merger of relationship conditions
# relationship
}
else {
- my @unique_queries = $self->_unique_queries($input_query, $attrs);
- $query = @unique_queries
- ? [ map { $self->_add_alias($_, $alias) } @unique_queries ]
- : $self->_add_alias($input_query, $alias);
+ # no key was specified - fall down to heuristics mode:
+ # run through all unique queries registered on the resultset, and
+ # 'OR' all qualifying queries together
+ my (@unique_queries, %seen_column_combinations);
+ for my $c_name ($rsrc->unique_constraint_names) {
+ next if $seen_column_combinations{
+ join "\x00", sort $rsrc->unique_constraint_columns($c_name)
+ }++;
+
+ push @unique_queries, try {
+ $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
+ } || ();
+ }
+
+ $final_cond = @unique_queries
+ ? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
+ : $self->_non_unique_find_fallback ($call_cond, $attrs)
+ ;
}
- # Run the query
- my $rs = $self->search ($query, {result_class => $self->result_class, %$attrs});
+ # Run the query, passing the result_class since it should propagate for find
+ my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
if ($rs->_resolved_attrs->{collapse}) {
my $row = $rs->next;
carp "Query returned more than one row" if $rs->next;
}
}
-# _add_alias
+# This is a stop-gap method as agreed during the discussion on find() cleanup:
+# http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
#
-# Add the specified alias to the specified query hash. A copy is made so the
-# original query is not modified.
+# It is invoked when find() is called in legacy-mode with insufficiently-unique
+# condition. It is provided for overrides until a saner way forward is devised
+#
+# *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
+# the road. Please adjust your tests accordingly to catch this situation early
+# DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
+#
+# The method will not be removed without an adequately complete replacement
+# for strict-mode enforcement
+sub _non_unique_find_fallback {
+ my ($self, $cond, $attrs) = @_;
+
+ return $self->_qualify_cond_columns(
+ $cond,
+ exists $attrs->{alias}
+ ? $attrs->{alias}
+ : $self->{attrs}{alias}
+ );
+}
-sub _add_alias {
- my ($self, $query, $alias) = @_;
- my %aliased = %$query;
- foreach my $col (grep { ! m/\./ } keys %aliased) {
- $aliased{"$alias.$col"} = delete $aliased{$col};
+sub _qualify_cond_columns {
+ my ($self, $cond, $alias) = @_;
+
+ my %aliased = %$cond;
+ for (keys %aliased) {
+ $aliased{"$alias.$_"} = delete $aliased{$_}
+ if $_ !~ /\./;
}
return \%aliased;
}
-# _unique_queries
-#
-# Build a list of queries which satisfy unique constraints.
-
-sub _unique_queries {
- my ($self, $query, $attrs) = @_;
-
- my @constraint_names = exists $attrs->{key}
- ? ($attrs->{key})
- : $self->result_source->unique_constraint_names;
+sub _build_unique_cond {
+ my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
- my $where = $self->_collapse_cond($self->{attrs}{where} || {});
- my $num_where = scalar keys %$where;
+ my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
- my (@unique_queries, %seen_column_combinations);
- foreach my $name (@constraint_names) {
- my @constraint_cols = $self->result_source->unique_constraint_columns($name);
-
- my $constraint_sig = join "\x00", sort @constraint_cols;
- next if $seen_column_combinations{$constraint_sig}++;
-
- my $unique_query = $self->_build_unique_query($query, \@constraint_cols);
+ # combination may fail if $self->{cond} is non-trivial
+ my ($final_cond) = try {
+ $self->_merge_with_rscond ($extra_cond)
+ } catch {
+ +{ %$extra_cond }
+ };
- my $num_cols = scalar @constraint_cols;
- my $num_query = scalar keys %$unique_query;
+ # trim out everything not in $columns
+ $final_cond = { map {
+ exists $final_cond->{$_}
+ ? ( $_ => $final_cond->{$_} )
+ : ()
+ } @c_cols };
- my $total = $num_query + $num_where;
- if ($num_query && ($num_query == $num_cols || $total == $num_cols)) {
- # The query is either unique on its own or is unique in combination with
- # the existing where clause
- push @unique_queries, $unique_query;
- }
+ if (my @missing = grep
+ { ! ($croak_on_null ? defined $final_cond->{$_} : exists $final_cond->{$_}) }
+ (@c_cols)
+ ) {
+ $self->throw_exception( sprintf ( "Unable to satisfy requested constraint '%s', no values for column(s): %s",
+ $constraint_name,
+ join (', ', map { "'$_'" } @missing),
+ ) );
}
- return @unique_queries;
-}
-
-# _build_unique_query
-#
-# Constrain the specified query hash based on the specified column names.
-
-sub _build_unique_query {
- my ($self, $query, $unique_cols) = @_;
+ if (
+ !$croak_on_null
+ and
+ !$ENV{DBIC_NULLABLE_KEY_NOWARN}
+ and
+ my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
+ ) {
+ carp_unique ( sprintf (
+ "NULL/undef values supplied for requested unique constraint '%s' (NULL "
+ . 'values in column(s): %s). This is almost certainly not what you wanted, '
+ . 'though you can set DBIC_NULLABLE_KEY_NOWARN to disable this warning.',
+ $constraint_name,
+ join (', ', map { "'$_'" } @undefs),
+ ));
+ }
- return {
- map { $_ => $query->{$_} }
- grep { exists $query->{$_} }
- @$unique_cols
- };
+ return $final_cond;
}
=head2 search_related
=over 4
-=item Arguments: $rel, $cond, \%attrs?
+=item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
-=item Return Value: $new_resultset
+=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
=back
Searches the specified relationship, optionally specifying a condition and
attributes for matching records. See L</ATTRIBUTES> for more information.
+In list context, C<< ->all() >> is called implicitly on the resultset, thus
+returning a list of result objects instead. To avoid that, use L</search_related_rs>.
+
+See also L</search_related_rs>.
+
=cut
sub search_related {
=item Arguments: none
-=item Return Value: $cursor
+=item Return Value: L<$cursor|DBIx::Class::Cursor>
=back
=cut
sub cursor {
- my ($self) = @_;
-
- my $attrs = $self->_resolved_attrs_copy;
+ my $self = shift;
- return $self->{cursor}
- ||= $self->result_source->storage->select($attrs->{from}, $attrs->{select},
- $attrs->{where},$attrs);
+ return $self->{cursor} ||= do {
+ my $attrs = $self->_resolved_attrs;
+ $self->result_source->storage->select(
+ $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
+ );
+ };
}
=head2 single
=over 4
-=item Arguments: $cond?
+=item Arguments: L<$cond?|DBIx::Class::SQLMaker>
-=item Return Value: $row_object?
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
=back
my $cd = $schema->resultset('CD')->single({ year => 2001 });
Inflates the first result without creating a cursor if the resultset has
-any records in it; if not returns nothing. Used by L</find> as a lean version of
-L</search>.
+any records in it; if not returns C<undef>. Used by L</find> as a lean version
+of L</search>.
While this method can take an optional search condition (just like L</search>)
being a fast-code-path it does not recognize search attributes. If you need to
$self->throw_exception('single() only takes search conditions, no attributes. You want ->search( $cond, $attrs )->single()');
}
- my $attrs = $self->_resolved_attrs_copy;
+ my $attrs = { %{$self->_resolved_attrs} };
- if ($attrs->{collapse}) {
- $self->throw_exception(
- 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
- );
- }
+ $self->throw_exception(
+ 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
+ ) if $attrs->{collapse};
if ($where) {
if (defined $attrs->{where}) {
}
}
-# XXX: Disabled since it doesn't infer uniqueness in all cases
-# unless ($self->_is_unique_query($attrs->{where})) {
-# carp "Query not guaranteed to return a single row"
-# . "; please declare your unique constraints or use search instead";
-# }
-
- my @data = $self->result_source->storage->select_single(
+ my $data = [ $self->result_source->storage->select_single(
$attrs->{from}, $attrs->{select},
$attrs->{where}, $attrs
- );
+ )];
- return @data
- ? ($self->_construct_objects(@data))[0]
- : undef
- ;
+ return undef unless @$data;
+ $self->{_stashed_rows} = [ $data ];
+ $self->_construct_results->[0];
}
-# _is_unique_query
-#
-# Try to determine if the specified query is guaranteed to be unique, based on
-# the declared unique constraints.
-
-sub _is_unique_query {
- my ($self, $query) = @_;
-
- my $collapsed = $self->_collapse_query($query);
- my $alias = $self->{attrs}{alias};
-
- foreach my $name ($self->result_source->unique_constraint_names) {
- my @unique_cols = map {
- "$alias.$_"
- } $self->result_source->unique_constraint_columns($name);
-
- # Count the values for each unique column
- my %seen = map { $_ => 0 } @unique_cols;
-
- foreach my $key (keys %$collapsed) {
- my $aliased = $key =~ /\./ ? $key : "$alias.$key";
- next unless exists $seen{$aliased}; # Additional constraints are okay
- $seen{$aliased} = scalar keys %{ $collapsed->{$key} };
- }
-
- # If we get 0 or more than 1 value for a column, it's not necessarily unique
- return 1 unless grep { $_ != 1 } values %seen;
- }
-
- return 0;
-}
-
# _collapse_query
#
# Recursively collapse the query, accumulating values for each column.
=over 4
-=item Arguments: $cond?
+=item Arguments: L<$cond?|DBIx::Class::SQLMaker>
-=item Return Value: $resultsetcolumn
+=item Return Value: L<$resultsetcolumn|DBIx::Class::ResultSetColumn>
=back
=over 4
-=item Arguments: $cond, \%attrs?
+=item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
-=item Return Value: $resultset (scalar context), @row_objs (list context)
+=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
=back
sub search_like {
my $class = shift;
- carp (
+ carp_unique (
'search_like() is deprecated and will be removed in DBIC version 0.09.'
.' Instead use ->search({ x => { -like => "y%" } })'
.' (note the outer pair of {}s - they are important!)'
=item Arguments: $first, $last
-=item Return Value: $resultset (scalar context), @row_objs (list context)
+=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
=back
$attrs->{offset} = $self->{attrs}{offset} || 0;
$attrs->{offset} += $min;
$attrs->{rows} = ($max ? ($max - $min + 1) : 1);
- return $self->search(undef(), $attrs);
+ return $self->search(undef, $attrs);
#my $slice = (ref $self)->new($self->result_source, $attrs);
#return (wantarray ? $slice->all : $slice);
}
=over 4
-=item Arguments: none
-
-=item Return Value: $result?
-
-=back
-
-Returns the next element in the resultset (C<undef> is there is none).
-
-Can be used to efficiently iterate over records in the resultset:
-
- my $rs = $schema->resultset('CD')->search;
- while (my $cd = $rs->next) {
- print $cd->title;
- }
-
-Note that you need to store the resultset object, and call C<next> on it.
-Calling C<< resultset('Table')->next >> repeatedly will always return the
-first record from the resultset.
-
-=cut
-
-sub next {
- my ($self) = @_;
- if (my $cache = $self->get_cache) {
- $self->{all_cache_position} ||= 0;
- return $cache->[$self->{all_cache_position}++];
- }
- if ($self->{attrs}{cache}) {
- $self->{all_cache_position} = 1;
- return ($self->all)[0];
- }
- if ($self->{stashed_objects}) {
- my $obj = shift(@{$self->{stashed_objects}});
- delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
- return $obj;
- }
- my @row = (
- exists $self->{stashed_row}
- ? @{delete $self->{stashed_row}}
- : $self->cursor->next
- );
- return undef unless (@row);
- my ($row, @more) = $self->_construct_objects(@row);
- $self->{stashed_objects} = \@more if @more;
- return $row;
-}
-
-# takes a single DBI-row of data and coinstructs as many objects
-# as the resultset attributes call for.
-# This can be a bit of an action at a distance - it takes as an argument
-# the *current* cursor-row (already taken off the $sth), but if
-# collapsing is requested it will keep advancing the cursor either
-# until the current row-object is assembled (the collapser was able to
-# order the result sensibly) OR until the cursor is exhausted (an
-# unordered collapsing resultset effectively triggers ->all)
-
-# FIXME: why the *FUCK* do we pass around DBI data by copy?! Sadly needs
-# assessment before changing...
-#
-sub _construct_objects {
- my ($self, @row) = @_;
- my $attrs = $self->_resolved_attrs;
- my $keep_collapsing = $attrs->{collapse};
-
- my $res_index;
-=begin
- do {
- my $me_pref_col = $attrs->{_row_parser}->($row_ref);
-
- my $container;
- if ($keep_collapsing) {
-
- # FIXME - we should be able to remove these 2 checks after the design validates
- $self->throw_exception ('Collapsing without a top-level collapse-set... can not happen')
- unless @{$me_ref_col->[2]};
- $self->throw_exception ('Top-level collapse-set contains a NULL-value... can not happen')
- if grep { ! defined $_ } @{$me_pref_col->[2]};
-
- my $main_ident = join "\x00", @{$me_pref_col->[2]};
-
- if (! $res_index->{$main_ident}) {
- # this is where we bail out IFF we are ordered, and the $main_ident changes
-
- $res_index->{$main_ident} = {
- all_me_pref => [,
- index => scalar keys %$res_index,
- };
- }
- }
-
-
-
- $container = $res_index->{$main_ident}{container};
- };
-
- push @$container, [ @{$me_pref_col}[0,1] ];
-
-
-
- } while (
- $keep_collapsing
- &&
- do { $row_ref = [$self->cursor->next]; $self->{stashed_row} = $row_ref if @$row_ref; scalar @$row_ref }
- );
-
- # attempt collapse all rows with same collapse identity
- if (@to_collapse > 1) {
- my @collapsed;
- while (@to_collapse) {
- $self->_merge_result(\@collapsed, shift @to_collapse);
- }
- }
-=cut
-
- my $mepref_structs = $self->_collapse_result($attrs->{as}, \@row, $keep_collapsing)
- or return ();
-
- my $rsrc = $self->result_source;
- my $res_class = $self->result_class;
- my $inflator = $res_class->can ('inflate_result');
-
- my @objs =
- $res_class->$inflator ($rsrc, @$mepref_structs);
-
- if (my $f = $attrs->{record_filter}) {
- @objs = map { $f->($_) } @objs;
- }
-
- return @objs;
-}
-
-
-sub _collapse_result {
- my ( $self, $as_proto, $row_ref, $keep_collapsing ) = @_;
- my $collapse = $self->_resolved_attrs->{collapse};
- my $parser = $self->result_source->_mk_row_parser( $as_proto, $collapse );
- my $result = [];
- my $register = {};
- my $rel_register = {};
-
- my @row = @$row_ref;
- do {
- my $row = $parser->( \@row );
-
- # init register
- $self->_check_register( $register, $row ) unless ( keys %$register );
-
- $self->_merge_result( $result, $row, $rel_register )
- if ( !$collapse
- || ( $collapse = $self->_check_register( $register, $row ) ) );
+=item Arguments: none
- } while (
- $collapse
- && do { @row = $self->cursor->next; $self->{stashed_row} = \@row if @row; }
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
- # run this as long as there is a next row and we are not yet done collapsing
- );
- return $result;
-}
+=back
+Returns the next element in the resultset (C<undef> is there is none).
+Can be used to efficiently iterate over records in the resultset:
-# Taubenschlag
-sub _check_register {
- my ( $self, $register, $obj ) = @_;
- return undef unless ( ref $obj eq 'ARRAY' && ref $obj->[2] eq 'ARRAY' );
- my @ids = @{ $obj->[2] };
- while ( defined( my $id = shift @ids ) ) {
- return $register->{$id} if ( exists $register->{$id} && !@ids );
- $register->{$id} = @ids ? {} : $obj unless ( exists $register->{$id} );
- $register = $register->{$id};
+ my $rs = $schema->resultset('CD')->search;
+ while (my $cd = $rs->next) {
+ print $cd->title;
}
- return undef;
-}
+Note that you need to store the resultset object, and call C<next> on it.
+Calling C<< resultset('Table')->next >> repeatedly will always return the
+first record from the resultset.
+
+=cut
-sub _merge_result {
- my ( $self, $result, $row, $register ) = @_;
- return @$result = @$row if ( @$result == 0 ); # initialize with $row
+sub next {
+ my ($self) = @_;
- my ( undef, $rels, $ids ) = @$result;
- my ( undef, $new_rels, $new_ids ) = @$row;
+ if (my $cache = $self->get_cache) {
+ $self->{all_cache_position} ||= 0;
+ return $cache->[$self->{all_cache_position}++];
+ }
- use List::MoreUtils;
- my @rels = List::MoreUtils::uniq( keys %$rels, keys %$new_rels );
- foreach my $rel (@rels) {
- $register = $register->{$rel} ||= {};
+ if ($self->{attrs}{cache}) {
+ delete $self->{pager};
+ $self->{all_cache_position} = 1;
+ return ($self->all)[0];
+ }
- my $new_data = $new_rels->{$rel};
- my $data = $rels->{$rel};
- @$data = [@$data] unless ( ref $data->[0] eq 'ARRAY' );
+ return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
- $self->_check_register( $register, $data->[0] )
- unless ( keys %$register );
+ $self->{_stashed_results} = $self->_construct_results
+ or return undef;
- if ( my $found = $self->_check_register( $register, $new_data ) ) {
- $self->_merge_result( $found, $new_data, $register );
- }
- else {
- push( @$data, $new_data );
- }
- }
- return 1;
+ return shift @{$self->{_stashed_results}};
}
+# Constructs as many results as it can in one pass while respecting
+# cursor laziness. Several modes of operation:
+#
+# * Always builds everything present in @{$self->{_stashed_rows}}
+# * If called with $fetch_all true - pulls everything off the cursor and
+# builds all result structures (or objects) in one pass
+# * If $self->_resolved_attrs->{collapse} is true, checks the order_by
+# and if the resultset is ordered properly by the left side:
+# * Fetches stuff off the cursor until the "master object" changes,
+# and saves the last extra row (if any) in @{$self->{_stashed_rows}}
+# OR
+# * Just fetches, and collapses/constructs everything as if $fetch_all
+# was requested (there is no other way to collapse except for an
+# eager cursor)
+# * If no collapse is requested - just get the next row, construct and
+# return
+sub _construct_results {
+ my ($self, $fetch_all) = @_;
+ my $rsrc = $self->result_source;
+ my $attrs = $self->_resolved_attrs;
+ if (
+ ! $fetch_all
+ and
+ ! $attrs->{order_by}
+ and
+ $attrs->{collapse}
+ and
+ my @pcols = $rsrc->primary_columns
+ ) {
+ # default order for collapsing unless the user asked for something
+ $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
+ $attrs->{_ordered_for_collapse} = 1;
+ $attrs->{_order_is_artificial} = 1;
+ }
-=begin
+ # this will be used as both initial raw-row collector AND as a RV of
+ # _construct_results. Not regrowing the array twice matters a lot...
+ # a surprising amount actually
+ my $rows = delete $self->{_stashed_rows};
-# two arguments: $as_proto is an arrayref of column names,
-# $row_ref is an arrayref of the data. If none of the row data
-# is defined we return undef (that's copied from the old
-# _collapse_result). Next we decide whether we need to collapse
-# the resultset (i.e. we prefetch something) or not. $collapse
-# indicates that. The do-while loop will run once if we do not need
-# to collapse the result and will run as long as _merge_result returns
-# a true value. It will return undef if the current added row does not
-# match the previous row. A bit of stashing and cursor magic is
-# required so that the cursor is not mixed up.
+ my $cursor; # we may not need one at all
-# "$rows" is a bit misleading. In the end, there should only be one
-# element in this arrayref.
+ my $did_fetch_all = $fetch_all;
-sub _collapse_result {
- my ( $self, $as_proto, $row_ref ) = @_;
- my $has_def;
- for (@$row_ref) {
- if ( defined $_ ) {
- $has_def++;
- last;
- }
+ if ($fetch_all) {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
+ }
+ elsif( $attrs->{collapse} ) {
+
+ # a cursor will need to be closed over in case of collapse
+ $cursor = $self->cursor;
+
+ $attrs->{_ordered_for_collapse} = (
+ (
+ $attrs->{order_by}
+ and
+ $rsrc->schema
+ ->storage
+ ->_main_source_order_by_portion_is_stable($rsrc, $attrs->{order_by}, $attrs->{where})
+ ) ? 1 : 0
+ ) unless defined $attrs->{_ordered_for_collapse};
+
+ if (! $attrs->{_ordered_for_collapse}) {
+ $did_fetch_all = 1;
+
+ # instead of looping over ->next, use ->all in stealth mode
+ # *without* calling a ->reset afterwards
+ # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
+ if (! $cursor->{_done}) {
+ $rows = [ ($rows ? @$rows : ()), $cursor->all ];
+ $cursor->{_done} = 1;
+ }
}
- return undef unless $has_def;
-
- my $collapse = $self->_resolved_attrs->{collapse};
- my $rows = [];
- my @row = @$row_ref;
- do {
- my $i = 0;
- my $row = { map { $_ => $row[ $i++ ] } @$as_proto };
- $row = $self->result_source->_parse_row($row, $collapse);
- unless ( scalar @$rows ) {
- push( @$rows, $row );
- }
- $collapse = undef unless ( $self->_merge_result( $rows, $row ) );
- } while (
- $collapse
- && do { @row = $self->cursor->next; $self->{stashed_row} = \@row if @row; }
- );
-
- return $rows->[0];
-
-}
+ }
-# _merge_result accepts an arrayref of rows objects (again, an arrayref of two elements)
-# and a row object which should be merged into the first object.
-# First we try to find out whether $row is already in $rows. If this is the case
-# we try to merge them by iteration through their relationship data. We call
-# _merge_result again on them, so they get merged.
+ if (! $did_fetch_all and ! @{$rows||[]} ) {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ $cursor ||= $self->cursor;
+ if (scalar (my @r = $cursor->next) ) {
+ $rows = [ \@r ];
+ }
+ }
-# If we don't find the $row in $rows, we append it to $rows and return undef.
-# _merge_result returns 1 otherwise (i.e. $row has been found in $rows).
+ return undef unless @{$rows||[]};
-sub _merge_result {
- my ( $self, $rows, $row ) = @_;
- my ( $columns, $rels ) = @$row;
- my $found = undef;
- foreach my $seen (@$rows) {
- my $match = 1;
- foreach my $column ( keys %$columns ) {
- if ( defined $seen->[0]->{$column} ^ defined $columns->{$column}
- or defined $columns->{$column}
- && $seen->[0]->{$column} ne $columns->{$column} )
- {
+ # sanity check - people are too clever for their own good
+ if ($attrs->{collapse} and my $aliastypes = $attrs->{_sqlmaker_select_args}[3]{_aliastypes} ) {
- $match = 0;
- last;
- }
- }
- if ($match) {
- $found = $seen;
- last;
- }
+ my $multiplied_selectors;
+ for my $sel_alias ( grep { $_ ne $attrs->{alias} } keys %{ $aliastypes->{selecting} } ) {
+ if (
+ $aliastypes->{multiplying}{$sel_alias}
+ or
+ scalar grep { $aliastypes->{multiplying}{(values %$_)[0]} } @{ $aliastypes->{selecting}{$sel_alias}{-parents} }
+ ) {
+ $multiplied_selectors->{$_} = 1 for values %{$aliastypes->{selecting}{$sel_alias}{-seen_columns}}
+ }
}
- if ($found) {
- foreach my $rel ( keys %$rels ) {
- my $old_rows = $found->[1]->{$rel};
- $self->_merge_result(
- ref $found->[1]->{$rel}->[0] eq 'HASH' ? [ $found->[1]->{$rel} ]
- : $found->[1]->{$rel},
- ref $rels->{$rel}->[0] eq 'HASH' ? [ $rels->{$rel}->[0], $rels->{$rel}->[1] ]
- : $rels->{$rel}->[0]
- );
-
- my $attrs = $self->_resolved_attrs;
- my ($keep_collapsing, $set_ident) = @{$attrs}{qw/collapse _collapse_ident/};
-
- # FIXME this is temporary, need to calculate in _resolved_attrs
- $set_ident ||= { me => [ $self->result_source->_pri_cols ], pref => {} };
-
- my @cur_row = @$row_ref;
- my (@to_collapse, $last_ident);
-
- do {
- my $row_hr = { map { $as_proto->[$_] => $cur_row[$_] } (0 .. $#$as_proto) };
-
- # see if we are switching to another object
- # this can be turned off and things will still work
- # since _merge_prefetch knows about _collapse_ident
-# my $cur_ident = [ @{$row_hr}{@$set_ident} ];
- my $cur_ident = [];
- $last_ident ||= $cur_ident;
-
-# if ($keep_collapsing = Test::Deep::eq_deeply ($cur_ident, $last_ident)) {
-# push @to_collapse, $self->result_source->_parse_row (
-# $row_hr,
-# );
-# }
- } while (
- $keep_collapsing
- &&
- do { @cur_row = $self->cursor->next; $self->{stashed_row} = \@cur_row if @cur_row; }
- );
- die Dumper \@to_collapse;
+ for my $i (0 .. $#{$attrs->{as}} ) {
+ my $sel = $attrs->{select}[$i];
+ if (ref $sel eq 'SCALAR') {
+ $sel = $$sel;
+ }
+ elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
+ $sel = $$sel->[0];
+ }
- # attempt collapse all rows with same collapse identity
- if (@to_collapse > 1) {
- my @collapsed;
- while (@to_collapse) {
- $self->_merge_result(\@collapsed, shift @to_collapse);
+ $self->throw_exception(
+ 'Result collapse not possible - selection from a has_many source redirected to the main object'
+ ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
}
- @to_collapse = @collapsed;
}
- # still didn't fully collapse
- $self->throw_exception ('Resultset collapse failed (theoretically impossible). Maybe a wrong collapse_ident...?')
- if (@to_collapse > 1);
+ # hotspot - skip the setter
+ my $res_class = $self->_result_class;
- return $to_collapse[0];
-}
-
-
-# two arguments: $as_proto is an arrayref of 'as' column names,
-# $row_ref is an arrayref of the data. The do-while loop will run
-# once if we do not need to collapse the result and will run as long as
-# _merge_result returns a true value. It will return undef if the
-# current added row does not match the previous row, which in turn
-# means we need to stash the row for the subsequent ->next call
-sub _collapse_result {
- my ( $self, $as_proto, $row_ref ) = @_;
+ my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
+ $res_class->can ('inflate_result')
+ or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
+ };
- my $attrs = $self->_resolved_attrs;
- my ($keep_collapsing, $set_ident) = @{$attrs}{qw/collapse _collapse_ident/};
+ my $infmap = $attrs->{as};
- die Dumper [$as_proto, $row_ref, $keep_collapsing, $set_ident ];
+ $self->{_result_inflator}{is_core_row} = ( (
+ $inflator_cref
+ ==
+ ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
+ ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
+ $self->{_result_inflator}{is_hri} = ( (
+ ! $self->{_result_inflator}{is_core_row}
+ and
+ $inflator_cref == (
+ require DBIx::Class::ResultClass::HashRefInflator
+ &&
+ DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
+ )
+ ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
+
+
+ if (! $attrs->{_related_results_construction}) {
+ # construct a much simpler array->hash folder for the one-table cases right here
+ if ($self->{_result_inflator}{is_hri}) {
+ for my $r (@$rows) {
+ $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
+ }
+ }
+ # FIXME SUBOPTIMAL this is a very very very hot spot
+ # while rather optimal we can *still* do much better, by
+ # building a smarter Row::inflate_result(), and
+ # switch to feeding it data via a much leaner interface
+ #
+ # crude unscientific benchmarking indicated the shortcut eval is not worth it for
+ # this particular resultset size
+ elsif (@$rows < 60) {
+ for my $r (@$rows) {
+ $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
+ }
+ }
+ else {
+ eval sprintf (
+ '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
+ join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
+ );
+ }
+ }
+ else {
+ my $parser_type =
+ $self->{_result_inflator}{is_hri} ? 'hri'
+ : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
+ : 'classic_nonpruning'
+ ;
- my @cur_row = @$row_ref;
- my (@to_collapse, $last_ident);
+ # $args and $attrs to _mk_row_parser are seperated to delineate what is
+ # core collapser stuff and what is dbic $rs specific
+ @{$self->{_row_parser}{$parser_type}}{qw(cref nullcheck)} = $rsrc->_mk_row_parser({
+ eval => 1,
+ inflate_map => $infmap,
+ collapse => $attrs->{collapse},
+ premultiplied => $attrs->{_main_source_premultiplied},
+ hri_style => $self->{_result_inflator}{is_hri},
+ prune_null_branches => $self->{_result_inflator}{is_hri} || $self->{_result_inflator}{is_core_row},
+ }, $attrs) unless $self->{_row_parser}{$parser_type}{cref};
+
+ # column_info metadata historically hasn't been too reliable.
+ # We need to start fixing this somehow (the collapse resolver
+ # can't work without it). Add an explicit check for the *main*
+ # result, hopefully this will gradually weed out such errors
+ #
+ # FIXME - this is a temporary kludge that reduces perfromance
+ # It is however necessary for the time being
+ my ($unrolled_non_null_cols_to_check, $err);
+
+ if (my $check_non_null_cols = $self->{_row_parser}{$parser_type}{nullcheck} ) {
+
+ $err =
+ 'Collapse aborted due to invalid ResultSource metadata - the following '
+ . 'selections are declared non-nullable but NULLs were retrieved: '
+ ;
- do {
- my $row_hr = { map { $as_proto->[$_] => $cur_row[$_] } (0 .. $#$as_proto) };
+ my @violating_idx;
+ COL: for my $i (@$check_non_null_cols) {
+ ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
+ }
- # see if we are switching to another object
- # this can be turned off and things will still work
- # since _merge_prefetch knows about _collapse_ident
-# my $cur_ident = [ @{$row_hr}{@$set_ident} ];
- my $cur_ident = [];
- $last_ident ||= $cur_ident;
+ $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
+ if @violating_idx;
-# if ($keep_collapsing = eq_deeply ($cur_ident, $last_ident)) {
-# push @to_collapse, $self->result_source->_parse_row (
-# $row_hr,
-# );
-# }
- } while (
- $keep_collapsing
- &&
- do { @cur_row = $self->cursor->next; $self->{stashed_row} = \@cur_row if @cur_row; }
- );
+ $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
+ }
- # attempt collapse all rows with same collapse identity
+ my $next_cref =
+ ($did_fetch_all or ! $attrs->{collapse}) ? undef
+ : defined $unrolled_non_null_cols_to_check ? eval sprintf <<'EOS', $unrolled_non_null_cols_to_check
+sub {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ my @r = $cursor->next or return;
+ if (my @violating_idx = grep { ! defined $r[$_] } (%s) ) {
+ $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
+ }
+ \@r
}
-=cut
+EOS
+ : sub {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ my @r = $cursor->next or return;
+ \@r
+ }
+ ;
-# Takes an arrayref of me/pref pairs and a new me/pref pair that should
-# be merged on a preexisting matching me (or should be pushed into $merged
-# as a new me/pref pair for further invocations). It should be possible to
-# use this function to collapse complete ->all results, provided _collapse_result() is adjusted
-# to provide everything to this sub not to barf when $merged contains more than one
-# arrayref)
-sub _merge_prefetch {
- my ($self, $merged, $next_row) = @_;
+ $self->{_row_parser}{$parser_type}{cref}->(
+ $rows,
+ $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
+ );
- unless (@$merged) {
- push @$merged, $next_row;
- return;
+ # Special-case multi-object HRI - there is no $inflator_cref pass
+ unless ($self->{_result_inflator}{is_hri}) {
+ $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows
+ }
}
+ # The @$rows check seems odd at first - why wouldn't we want to warn
+ # regardless? The issue is things like find() etc, where the user
+ # *knows* only one result will come back. In these cases the ->all
+ # is not a pessimization, but rather something we actually want
+ carp_unique(
+ 'Unable to properly collapse has_many results in iterator mode due '
+ . 'to order criteria - performed an eager cursor slurp underneath. '
+ . 'Consider using ->all() instead'
+ ) if ( ! $fetch_all and @$rows > 1 );
+
+ return $rows;
}
=head2 result_source
=over 4
-=item Arguments: $result_source?
+=item Arguments: L<$result_source?|DBIx::Class::ResultSource>
-=item Return Value: $result_source
+=item Return Value: L<$result_source|DBIx::Class::ResultSource>
=back
=back
-An accessor for the class to use when creating row objects. Defaults to
+An accessor for the class to use when creating result objects. Defaults to
C<< result_source->result_class >> - which in most cases is the name of the
L<"table"|DBIx::Class::Manual::Glossary/"ResultSource"> class.
sub result_class {
my ($self, $result_class) = @_;
if ($result_class) {
- $self->ensure_class_loaded($result_class);
+
+ # don't fire this for an object
+ $self->ensure_class_loaded($result_class)
+ unless ref($result_class);
+
+ if ($self->get_cache) {
+ carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
+ }
+ # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
+ elsif ($self->{cursor} && $self->{cursor}{_pos}) {
+ $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
+ }
+
$self->_result_class($result_class);
- $self->{attrs}{result_class} = $result_class if ref $self;
+
+ delete $self->{_result_inflator};
}
$self->_result_class;
}
=over 4
-=item Arguments: $cond, \%attrs??
+=item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
=item Return Value: $count
return $self->search(@_)->count if @_ and defined $_[0];
return scalar @{ $self->get_cache } if $self->get_cache;
- my $attrs = $self->_resolved_attrs_copy;
+ my $attrs = { %{ $self->_resolved_attrs } };
# this is a little optimization - it is faster to do the limit
# adjustments in software, instead of a subquery
- my $rows = delete $attrs->{rows};
- my $offset = delete $attrs->{offset};
+ my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
my $crs;
if ($self->_has_resolved_attr (qw/collapse group_by/)) {
=over 4
-=item Arguments: $cond, \%attrs??
+=item Arguments: L<$cond|DBIx::Class::SQLMaker>, L<\%attrs?|/ATTRIBUTES>
-=item Return Value: $count_rs
+=item Return Value: L<$count_rs|DBIx::Class::ResultSetColumn>
=back
# software based limiting can not be ported if this $rs is to be used
# in a subquery itself (i.e. ->as_query)
if ($self->_has_resolved_attr (qw/collapse group_by offset rows/)) {
- return $self->_count_subq_rs;
+ return $self->_count_subq_rs($self->{_attrs});
}
else {
- return $self->_count_rs;
+ return $self->_count_rs($self->{_attrs});
}
}
my ($self, $attrs) = @_;
my $rsrc = $self->result_source;
- $attrs ||= $self->_resolved_attrs;
my $tmp_attrs = { %$attrs };
-
- # take off any limits, record_filter is cdbi, and no point of ordering a count
- delete $tmp_attrs->{$_} for (qw/select as rows offset order_by record_filter/);
+ # take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
+ delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
# overwrite the selector (supplied by the storage)
- $tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $tmp_attrs);
- $tmp_attrs->{as} = 'count';
-
- my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
-
- return $tmp_rs;
+ $rsrc->resultset_class->new($rsrc, {
+ %$tmp_attrs,
+ select => $rsrc->storage->_count_select ($rsrc, $attrs),
+ as => 'count',
+ })->get_column ('count');
}
#
my ($self, $attrs) = @_;
my $rsrc = $self->result_source;
- $attrs ||= $self->_resolved_attrs_copy;
my $sub_attrs = { %$attrs };
+ # extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
+ delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
- # extra selectors do not go in the subquery and there is no point of ordering it
- delete $sub_attrs->{$_} for qw/collapse select _prefetch_select as order_by/;
-
- # if we multi-prefetch we group_by primary keys only as this is what we would
+ # if we multi-prefetch we group_by something unique, as this is what we would
# get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
if ( $attrs->{collapse} ) {
- $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->_pri_cols) ]
+ $sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
+ $rsrc->_identifying_column_set || $self->throw_exception(
+ 'Unable to construct a unique group_by criteria properly collapsing the '
+ . 'has_many prefetch before count()'
+ );
+ } ]
}
- $sub_attrs->{select} = $rsrc->storage->_subq_count_select ($rsrc, $attrs);
+ # Calculate subquery selector
+ if (my $g = $sub_attrs->{group_by}) {
- # this is so that the query can be simplified e.g.
- # * ordering can be thrown away in things like Top limit
- $sub_attrs->{-for_count_only} = 1;
+ my $sql_maker = $rsrc->storage->sql_maker;
- my $sub_rs = $rsrc->resultset_class->new ($rsrc, $sub_attrs);
+ # necessary as the group_by may refer to aliased functions
+ my $sel_index;
+ for my $sel (@{$attrs->{select}}) {
+ $sel_index->{$sel->{-as}} = $sel
+ if (ref $sel eq 'HASH' and $sel->{-as});
+ }
- $attrs->{from} = [{
- -alias => 'count_subq',
- -source_handle => $rsrc->handle,
- count_subq => $sub_rs->as_query,
- }];
+ # anything from the original select mentioned on the group-by needs to make it to the inner selector
+ # also look for named aggregates referred in the having clause
+ # having often contains scalarrefs - thus parse it out entirely
+ my @parts = @$g;
+ if ($attrs->{having}) {
+ local $sql_maker->{having_bind};
+ local $sql_maker->{quote_char} = $sql_maker->{quote_char};
+ local $sql_maker->{name_sep} = $sql_maker->{name_sep};
+ unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
+ $sql_maker->{quote_char} = [ "\x00", "\xFF" ];
+ # if we don't unset it we screw up retarded but unfortunately working
+ # 'MAX(foo.bar)' => { '>', 3 }
+ $sql_maker->{name_sep} = '';
+ }
- # the subquery replaces this
- delete $attrs->{$_} for qw/where bind collapse group_by having having_bind rows offset/;
+ my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
+
+ my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
+ my %seen_having;
+
+ # search for both a proper quoted qualified string, for a naive unquoted scalarref
+ # and if all fails for an utterly naive quoted scalar-with-function
+ while ($having_sql =~ /
+ $rquote $sep $lquote (.+?) $rquote
+ |
+ [\s,] \w+ \. (\w+) [\s,]
+ |
+ [\s,] $lquote (.+?) $rquote [\s,]
+ /gx) {
+ my $part = $1 || $2 || $3; # one of them matched if we got here
+ unless ($seen_having{$part}++) {
+ push @parts, $part;
+ }
+ }
+ }
- return $self->_count_rs ($attrs);
-}
+ for (@parts) {
+ my $colpiece = $sel_index->{$_} || $_;
-sub _bool {
- return 1;
+ # unqualify join-based group_by's. Arcane but possible query
+ # also horrible horrible hack to alias a column (not a func.)
+ # (probably need to introduce SQLA syntax)
+ if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
+ my $as = $colpiece;
+ $as =~ s/\./__/;
+ $colpiece = \ sprintf ('%s AS %s', map { $sql_maker->_quote ($_) } ($colpiece, $as) );
+ }
+ push @{$sub_attrs->{select}}, $colpiece;
+ }
+ }
+ else {
+ my @pcols = map { "$attrs->{alias}.$_" } ($rsrc->primary_columns);
+ $sub_attrs->{select} = @pcols ? \@pcols : [ 1 ];
+ }
+
+ return $rsrc->resultset_class
+ ->new ($rsrc, $sub_attrs)
+ ->as_subselect_rs
+ ->search ({}, { columns => { count => $rsrc->storage->_count_select ($rsrc, $attrs) } })
+ ->get_column ('count');
}
+
=head2 count_literal
+B<CAVEAT>: C<count_literal> is provided for Class::DBI compatibility and
+should only be used in that context. See L</search_literal> for further info.
+
=over 4
-=item Arguments: $sql_fragment, @bind_values
+=item Arguments: $sql_fragment, @standalone_bind_values
=item Return Value: $count
=item Arguments: none
-=item Return Value: @objects
+=item Return Value: L<@result_objs|DBIx::Class::Manual::ResultClass>
=back
-Returns all elements in the resultset. Called implicitly if the resultset
-is returned in list context.
+Returns all elements in the resultset.
=cut
sub all {
my $self = shift;
if(@_) {
- $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
+ $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
}
+ delete @{$self}{qw/_stashed_rows _stashed_results/};
+
if (my $c = $self->get_cache) {
return @$c;
}
- my @objects;
+ $self->cursor->reset;
- if ($self->_resolved_attrs->{collapse}) {
- # Using $self->cursor->all is really just an optimisation.
- # If we're collapsing has_many prefetches it probably makes
- # very little difference, and this is cleaner than hacking
- # _construct_objects to survive the approach
- $self->cursor->reset;
- my @row = $self->cursor->next;
- while (@row) {
- push(@objects, $self->_construct_objects(@row));
- @row = (exists $self->{stashed_row}
- ? @{delete $self->{stashed_row}}
- : $self->cursor->next);
- }
- } else {
- @objects = map { $self->_construct_objects(@$_) } $self->cursor->all;
- }
+ my $objs = $self->_construct_results('fetch_all') || [];
- $self->set_cache(\@objects) if $self->{attrs}{cache};
+ $self->set_cache($objs) if $self->{attrs}{cache};
- return @objects;
+ return @$objs;
}
=head2 reset
sub reset {
my ($self) = @_;
- delete $self->{_attrs} if exists $self->{_attrs};
+
+ delete @{$self}{qw/_stashed_rows _stashed_results/};
$self->{all_cache_position} = 0;
$self->cursor->reset;
return $self;
=item Arguments: none
-=item Return Value: $object?
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
=back
-Resets the resultset and returns an object for the first result (if the
-resultset returns anything).
+L<Resets|/reset> the resultset (causing a fresh query to storage) and returns
+an object for the first result (or C<undef> if the resultset is empty).
=cut
my ($self, $op, $values) = @_;
my $rsrc = $self->result_source;
+ my $storage = $rsrc->schema->storage;
+
+ my $attrs = { %{$self->_resolved_attrs} };
+
+ my $join_classifications;
+ my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
+
+ # do we need a subquery for any reason?
+ my $needs_subq = (
+ defined $existing_group_by
+ or
+ # if {from} is unparseable wrap a subq
+ ref($attrs->{from}) ne 'ARRAY'
+ or
+ # limits call for a subq
+ $self->_has_resolved_attr(qw/rows offset/)
+ );
- # if a condition exists we need to strip all table qualifiers
- # if this is not possible we'll force a subquery below
- my $cond = $rsrc->schema->storage->_strip_cond_qualifiers ($self->{cond});
+ # simplify the joinmap, so we can further decide if a subq is necessary
+ if (!$needs_subq and @{$attrs->{from}} > 1) {
- my $needs_group_by_subq = $self->_has_resolved_attr (qw/collapse group_by -join/);
- my $needs_subq = $needs_group_by_subq || (not defined $cond) || $self->_has_resolved_attr(qw/row offset/);
+ ($attrs->{from}, $join_classifications) =
+ $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $self->{cond}, $attrs);
- if ($needs_group_by_subq or $needs_subq) {
+ # any non-pruneable non-local restricting joins imply subq
+ $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
+ }
- # make a new $rs selecting only the PKs (that's all we really need)
- my $attrs = $self->_resolved_attrs_copy;
+ # check if the head is composite (by now all joins are thrown out unless $needs_subq)
+ $needs_subq ||= (
+ (ref $attrs->{from}[0]) ne 'HASH'
+ or
+ ref $attrs->{from}[0]{ $attrs->{from}[0]{-alias} }
+ );
- delete $attrs->{$_} for qw/collapse select as/;
- $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
+ my ($cond, $guard);
+ # do we need anything like a subquery?
+ if (! $needs_subq) {
+ # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus
+ # a condition containing 'me' or other table prefixes will not work
+ # at all. Tell SQLMaker to dequalify idents via a gross hack.
+ $cond = do {
+ my $sqla = $rsrc->storage->sql_maker;
+ local $sqla->{_dequalify_idents} = 1;
+ \[ $sqla->_recurse_where($self->{cond}) ];
+ };
+ }
+ else {
+ # we got this far - means it is time to wrap a subquery
+ my $idcols = $rsrc->_identifying_column_set || $self->throw_exception(
+ sprintf(
+ "Unable to perform complex resultset %s() without an identifying set of columns on source '%s'",
+ $op,
+ $rsrc->source_name,
+ )
+ );
- if ($needs_group_by_subq) {
- # make sure no group_by was supplied, or if there is one - make sure it matches
- # the columns compiled above perfectly. Anything else can not be sanely executed
- # on most databases so croak right then and there
+ # make a new $rs selecting only the PKs (that's all we really need for the subq)
+ delete $attrs->{$_} for qw/select as collapse/;
+ $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
- if (my $g = $attrs->{group_by}) {
- my @current_group_by = map
- { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
- @$g
- ;
+ # this will be consumed by the pruner waaaaay down the stack
+ $attrs->{_force_prune_multiplying_joins} = 1;
- if (
- join ("\x00", sort @current_group_by)
- ne
- join ("\x00", sort @{$attrs->{columns}} )
- ) {
- $self->throw_exception (
- "You have just attempted a $op operation on a resultset which does group_by"
- . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
- . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
- . ' kind of queries. Please retry the operation with a modified group_by or'
- . ' without using one at all.'
- );
+ my $subrs = (ref $self)->new($rsrc, $attrs);
+
+ if (@$idcols == 1) {
+ $cond = { $idcols->[0] => { -in => $subrs->as_query } };
+ }
+ elsif ($storage->_use_multicolumn_in) {
+ # no syntax for calling this properly yet
+ # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
+ $cond = $storage->sql_maker->_where_op_multicolumn_in (
+ $idcols, # how do I convey a list of idents...? can binds reside on lhs?
+ $subrs->as_query
+ ),
+ }
+ else {
+ # if all else fails - get all primary keys and operate over a ORed set
+ # wrap in a transaction for consistency
+ # this is where the group_by/multiplication starts to matter
+ if (
+ $existing_group_by
+ or
+ keys %{ $join_classifications->{multiplying} || {} }
+ ) {
+ # make sure if there is a supplied group_by it matches the columns compiled above
+ # perfectly. Anything else can not be sanely executed on most databases so croak
+ # right then and there
+ if ($existing_group_by) {
+ my @current_group_by = map
+ { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
+ @$existing_group_by
+ ;
+
+ if (
+ join ("\x00", sort @current_group_by)
+ ne
+ join ("\x00", sort @{$attrs->{columns}} )
+ ) {
+ $self->throw_exception (
+ "You have just attempted a $op operation on a resultset which does group_by"
+ . ' on columns other than the primary keys, while DBIC internally needs to retrieve'
+ . ' the primary keys in a subselect. All sane RDBMS engines do not support this'
+ . ' kind of queries. Please retry the operation with a modified group_by or'
+ . ' without using one at all.'
+ );
+ }
}
+
+ $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
}
- else {
- $attrs->{group_by} = $attrs->{columns};
+
+ $guard = $storage->txn_scope_guard;
+
+ $cond = [];
+ for my $row ($subrs->cursor->all) {
+ push @$cond, { map
+ { $idcols->[$_] => $row->[$_] }
+ (0 .. $#$idcols)
+ };
}
}
+ }
- my $subrs = (ref $self)->new($rsrc, $attrs);
+ my $res = $storage->$op (
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ $cond,
+ );
- return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
- }
- else {
- return $rsrc->storage->$op(
- $rsrc,
- $op eq 'update' ? $values : (),
- $cond,
- );
- }
+ $guard->commit if $guard;
+
+ return $res;
}
=head2 update
=item Arguments: \%values
-=item Return Value: $storage_rv
+=item Return Value: $underlying_storage_rv
=back
Sets the specified columns in the resultset to the supplied values in a
-single query. Return value will be true if the update succeeded or false
-if no records were updated; exact type of success value is storage-dependent.
+single query. Note that this will not run any accessor/set_column/update
+triggers, nor will it update any result object instances derived from this
+resultset (this includes the contents of the L<resultset cache|/set_cache>
+if any). See L</update_all> if you need to execute any on-update
+triggers or cascades defined either by you or a
+L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
+
+The return value is a pass through of what the underlying
+storage backend returned, and may vary. See L<DBI/execute> for the most
+common case.
+
+=head3 CAVEAT
+
+Note that L</update> does not process/deflate any of the values passed in.
+This is unlike the corresponding L<DBIx::Class::Row/update>. The user must
+ensure manually that any value passed to this method will stringify to
+something the RDBMS knows how to deal with. A notable example is the
+handling of L<DateTime> objects, for more info see:
+L<DBIx::Class::Manual::Cookbook/Formatting DateTime objects in queries>.
=cut
=back
-Fetches all objects and updates them one at a time. Note that C<update_all>
-will run DBIC cascade triggers, while L</update> will not.
+Fetches all objects and updates them one at a time via
+L<DBIx::Class::Row/update>. Note that C<update_all> will run DBIC defined
+triggers, while L</update> will not.
=cut
my ($self, $values) = @_;
$self->throw_exception('Values for update_all must be a hash')
unless ref $values eq 'HASH';
- foreach my $obj ($self->all) {
- $obj->set_columns($values)->update;
- }
+
+ my $guard = $self->result_source->schema->txn_scope_guard;
+ $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
+ $guard->commit;
return 1;
}
=item Arguments: none
-=item Return Value: $storage_rv
+=item Return Value: $underlying_storage_rv
=back
-Deletes the contents of the resultset from its result source. Note that this
-will not run DBIC cascade triggers. See L</delete_all> if you need triggers
-to run. See also L<DBIx::Class::Row/delete>.
+Deletes the rows matching this resultset in a single query. Note that this
+will not run any delete triggers, nor will it alter the
+L<in_storage|DBIx::Class::Row/in_storage> status of any result object instances
+derived from this resultset (this includes the contents of the
+L<resultset cache|/set_cache> if any). See L</delete_all> if you need to
+execute any on-delete triggers or cascades defined either by you or a
+L<result component|DBIx::Class::Manual::Component/WHAT IS A COMPONENT>.
-Return value will be the amount of rows deleted; exact type of return value
-is storage-dependent.
+The return value is a pass through of what the underlying storage backend
+returned, and may vary. See L<DBI/execute> for the most common case.
=cut
=back
-Fetches all objects and deletes them one at a time. Note that C<delete_all>
-will run DBIC cascade triggers, while L</delete> will not.
+Fetches all objects and deletes them one at a time via
+L<DBIx::Class::Row/delete>. Note that C<delete_all> will run DBIC defined
+triggers, while L</delete> will not.
=cut
$self->throw_exception('delete_all does not accept any arguments')
if @_;
+ my $guard = $self->result_source->schema->txn_scope_guard;
$_->delete for $self->all;
+ $guard->commit;
return 1;
}
=over 4
-=item Arguments: \@data;
+=item Arguments: [ \@column_list, \@row_values+ ] | [ \%col_data+ ]
+
+=item Return Value: L<\@result_objects|DBIx::Class::Manual::ResultClass> (scalar context) | L<@result_objects|DBIx::Class::Manual::ResultClass> (list context)
=back
-Accepts either an arrayref of hashrefs or alternatively an arrayref of arrayrefs.
-For the arrayref of hashrefs style each hashref should be a structure suitable
-forsubmitting to a $resultset->create(...) method.
+Accepts either an arrayref of hashrefs or alternatively an arrayref of
+arrayrefs.
+
+=over
+
+=item NOTE
-In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
-to insert the data, as this is a faster method.
+The context of this method call has an important effect on what is
+submitted to storage. In void context data is fed directly to fastpath
+insertion routines provided by the underlying storage (most often
+L<DBI/execute_for_fetch>), bypassing the L<new|DBIx::Class::Row/new> and
+L<insert|DBIx::Class::Row/insert> calls on the
+L<Result|DBIx::Class::Manual::ResultClass> class, including any
+augmentation of these methods provided by components. For example if you
+are using something like L<DBIx::Class::UUIDColumns> to create primary
+keys for you, you will find that your PKs are empty. In this case you
+will have to explicitly force scalar or list context in order to create
+those values.
-Otherwise, each set of data is inserted into the database using
-L<DBIx::Class::ResultSet/create>, and the resulting objects are
-accumulated into an array. The array itself, or an array reference
-is returned depending on scalar or list context.
+=back
+
+In non-void (scalar or list) context, this method is simply a wrapper
+for L</create>. Depending on list or scalar context either a list of
+L<Result|DBIx::Class::Manual::ResultClass> objects or an arrayref
+containing these objects is returned.
+
+When supplying data in "arrayref of arrayrefs" invocation style, the
+first element should be a list of column names and each subsequent
+element should be a data value in the earlier specified column order.
+For example:
-Example: Assuming an Artist Class that has many CDs Classes relating:
+ $Arstist_rs->populate([
+ [ qw( artistid name ) ],
+ [ 100, 'A Formally Unknown Singer' ],
+ [ 101, 'A singer that jumped the shark two albums ago' ],
+ [ 102, 'An actually cool singer' ],
+ ]);
- my $Artist_rs = $schema->resultset("Artist");
+For the arrayref of hashrefs style each hashref should be a structure
+suitable for passing to L</create>. Multi-create is also permitted with
+this syntax.
- ## Void Context Example
- $Artist_rs->populate([
+ $schema->resultset("Artist")->populate([
{ artistid => 4, name => 'Manufactured Crap', cds => [
{ title => 'My First CD', year => 2006 },
{ title => 'Yet More Tweeny-Pop crap', year => 2007 },
},
]);
- ## Array Context Example
- my ($ArtistOne, $ArtistTwo, $ArtistThree) = $Artist_rs->populate([
- { name => "Artist One"},
- { name => "Artist Two"},
- { name => "Artist Three", cds=> [
- { title => "First CD", year => 2007},
- { title => "Second CD", year => 2008},
- ]}
- ]);
-
- print $ArtistOne->name; ## response is 'Artist One'
- print $ArtistThree->cds->count ## reponse is '2'
-
-For the arrayref of arrayrefs style, the first element should be a list of the
-fieldsnames to which the remaining elements are rows being inserted. For
-example:
-
- $Arstist_rs->populate([
- [qw/artistid name/],
- [100, 'A Formally Unknown Singer'],
- [101, 'A singer that jumped the shark two albums ago'],
- [102, 'An actually cool singer'],
- ]);
-
-Please note an important effect on your data when choosing between void and
-wantarray context. Since void context goes straight to C<insert_bulk> in
-L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
-C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
-create primary keys for you, you will find that your PKs are empty. In this
-case you will have to use the wantarray context in order to create those
-values.
+If you attempt a void-context multi-create as in the example above (each
+Artist also has the related list of CDs), and B<do not> supply the
+necessary autoinc foreign key information, this method will proxy to the
+less efficient L</create>, and then throw the Result objects away. In this
+case there are obviously no benefits to using this method over L</create>.
=cut
# cruft placed in standalone method
my $data = $self->_normalize_populate_args(@_);
+ return unless @$data;
+
if(defined wantarray) {
- my @created;
- foreach my $item (@$data) {
- push(@created, $self->create($item));
- }
+ my @created = map { $self->create($_) } @$data;
return wantarray ? @created : \@created;
- } else {
+ }
+ else {
my $first = $data->[0];
# if a column is a registered relationship, and is a non-blessed hash/array, consider
# it relationship data
my (@rels, @columns);
+ my $rsrc = $self->result_source;
+ my $rels = { map { $_ => $rsrc->relationship_info($_) } $rsrc->relationships };
for (keys %$first) {
my $ref = ref $first->{$_};
- $self->result_source->has_relationship($_) && ($ref eq 'ARRAY' or $ref eq 'HASH')
+ $rels->{$_} && ($ref eq 'ARRAY' or $ref eq 'HASH')
? push @rels, $_
: push @columns, $_
;
}
- my @pks = $self->result_source->primary_columns;
+ my @pks = $rsrc->primary_columns;
## do the belongs_to relationships
foreach my $index (0..$#$data) {
foreach my $rel (@rels) {
next unless ref $data->[$index]->{$rel} eq "HASH";
my $result = $self->related_resultset($rel)->create($data->[$index]->{$rel});
- my ($reverse) = keys %{$self->result_source->reverse_relationship_info($rel)};
+ my ($reverse_relname, $reverse_relinfo) = %{$rsrc->reverse_relationship_info($rel)};
my $related = $result->result_source->_resolve_condition(
- $result->result_source->relationship_info($reverse)->{cond},
+ $reverse_relinfo->{cond},
$self,
$result,
+ $rel,
);
delete $data->[$index]->{$rel};
}
## inherit the data locked in the conditions of the resultset
- my ($rs_data) = $self->_merge_cond_with_data({});
+ my ($rs_data) = $self->_merge_with_rscond({});
delete @{$rs_data}{@columns};
- my @inherit_cols = keys %$rs_data;
- my @inherit_data = values %$rs_data;
## do bulk insert on current row
- $self->result_source->storage->insert_bulk(
- $self->result_source,
- [@columns, @inherit_cols],
- [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
+ $rsrc->storage->insert_bulk(
+ $rsrc,
+ [@columns, keys %$rs_data],
+ [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
);
## do the has_many relationships
foreach my $item (@$data) {
+ my $main_row;
+
foreach my $rel (@rels) {
- next unless $item->{$rel} && ref $item->{$rel} eq "ARRAY";
+ next unless ref $item->{$rel} eq "ARRAY" && @{ $item->{$rel} };
- my $parent = $self->find({map { $_ => $item->{$_} } @pks})
- || $self->throw_exception('Cannot find the relating object.');
+ $main_row ||= $self->new_result({map { $_ => $item->{$_} } @pks});
- my $child = $parent->$rel;
+ my $child = $main_row->$rel;
my $related = $child->result_source->_resolve_condition(
- $parent->result_source->relationship_info($rel)->{cond},
+ $rels->{$rel}{cond},
$child,
- $parent,
+ $main_row,
+ $rel,
);
my @rows_to_add = ref $item->{$rel} eq 'ARRAY' ? @{$item->{$rel}} : ($item->{$rel});
my ($self, $arg) = @_;
if (ref $arg eq 'ARRAY') {
- if (ref $arg->[0] eq 'HASH') {
+ if (!@$arg) {
+ return [];
+ }
+ elsif (ref $arg->[0] eq 'HASH') {
return $arg;
}
elsif (ref $arg->[0] eq 'ARRAY') {
=item Arguments: none
-=item Return Value: $pager
+=item Return Value: L<$pager|Data::Page>
=back
-Return Value a L<Data::Page> object for the current resultset. Only makes
+Returns a L<Data::Page> object for the current resultset. Only makes
sense for queries with a C<page> attribute.
To get the full count of entries for a paged resultset, call
return $self->{pager} if $self->{pager};
my $attrs = $self->{attrs};
- $self->throw_exception("Can't create pager for non-paged rs")
- unless $self->{attrs}{page};
+ if (!defined $attrs->{page}) {
+ $self->throw_exception("Can't create pager for non-paged rs");
+ }
+ elsif ($attrs->{page} <= 0) {
+ $self->throw_exception('Invalid page number (page-numbers are 1-based)');
+ }
$attrs->{rows} ||= 10;
# throw away the paging flags and re-run the count (possibly
# with a subselect) to get the real total count
my $count_attrs = { %$attrs };
- delete $count_attrs->{$_} for qw/rows offset page pager/;
- my $total_count = (ref $self)->new($self->result_source, $count_attrs)->count;
+ delete @{$count_attrs}{qw/rows offset page pager/};
- return $self->{pager} = Data::Page->new(
- $total_count,
+ my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
+
+ require DBIx::Class::ResultSet::Pager;
+ return $self->{pager} = DBIx::Class::ResultSet::Pager->new(
+ sub { $total_rs->count }, #lazy-get the total
$attrs->{rows},
- $self->{attrs}{page}
+ $self->{attrs}{page},
);
}
=item Arguments: $page_number
-=item Return Value: $rs
+=item Return Value: L<$resultset|/search>
=back
=over 4
-=item Arguments: \%vals
+=item Arguments: \%col_data
-=item Return Value: $rowobject
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
=back
-Creates a new row object in the resultset's result class and returns
+Creates a new result object in the resultset's result class and returns
it. The row is not inserted into the database at this point, call
L<DBIx::Class::Row/insert> to do that. Calling L<DBIx::Class::Row/in_storage>
-will tell you whether the row object has been inserted or not.
+will tell you whether the result object has been inserted or not.
Passes the hashref of input on to L<DBIx::Class::Row/new>.
sub new_result {
my ($self, $values) = @_;
- $self->throw_exception( "new_result needs a hash" )
+
+ $self->throw_exception( "new_result takes only one argument - a hashref of values" )
+ if @_ > 2;
+
+ $self->throw_exception( "new_result expects a hashref" )
unless (ref $values eq 'HASH');
- my ($merged_cond, $cols_from_relations) = $self->_merge_cond_with_data($values);
+ my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values);
- my %new = (
+ my $new = $self->result_class->new({
%$merged_cond,
- @$cols_from_relations
+ ( @$cols_from_relations
? (-cols_from_relations => $cols_from_relations)
- : (),
- -source_handle => $self->_source_handle,
+ : ()
+ ),
-result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
- );
+ });
+
+ if (
+ reftype($new) eq 'HASH'
+ and
+ ! keys %$new
+ and
+ blessed($new)
+ ) {
+ carp_unique (sprintf (
+ "%s->new returned a blessed empty hashref - a strong indicator something is wrong with its inheritance chain",
+ $self->result_class,
+ ));
+ }
- return $self->result_class->new(\%new);
+ $new;
}
-# _merge_cond_with_data
+# _merge_with_rscond
#
# Takes a simple hash of K/V data and returns its copy merged with the
# condition already present on the resultset. Additionally returns an
# arrayref of value/condition names, which were inferred from related
# objects (this is needed for in-memory related objects)
-sub _merge_cond_with_data {
+sub _merge_with_rscond {
my ($self, $data) = @_;
my (%new_data, @cols_from_relations);
my %implied = %{$self->_remove_alias($collapsed_cond, $alias)};
while ( my($col, $value) = each %implied ) {
- if (ref($value) eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
+ my $vref = ref $value;
+ if (
+ $vref eq 'HASH'
+ and
+ keys(%$value) == 1
+ and
+ (keys %$value)[0] eq '='
+ ) {
$new_data{$col} = $value->{'='};
- next;
}
- $new_data{$col} = $value if $self->_is_deterministic_value($value);
+ elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
+ $new_data{$col} = $value;
+ }
}
}
return (\%new_data, \@cols_from_relations);
}
-# _is_deterministic_value
-#
-# Make an effor to strip non-deterministic values from the condition,
-# to make sure new_result chokes less
-
-sub _is_deterministic_value {
- my $self = shift;
- my $value = shift;
- my $ref_type = ref $value;
- return 1 if $ref_type eq '' || $ref_type eq 'SCALAR';
- return 1 if Scalar::Util::blessed($value);
- return 0;
-}
-
# _has_resolved_attr
#
# determines if the resultset defines at least one
=item Arguments: none
-=item Return Value: \[ $sql, @bind ]
+=item Return Value: \[ $sql, L<@bind_values|/DBIC BIND VALUES> ]
=back
sub as_query {
my $self = shift;
- my $attrs = $self->_resolved_attrs_copy;
+ my $attrs = { %{ $self->_resolved_attrs } };
- # For future use:
- #
- # in list ctx:
- # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
- # $sql also has no wrapping parenthesis in list ctx
- #
- my $sqlbind = $self->result_source->storage
- ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
+ my $aq = $self->result_source->storage->_select_args_to_query (
+ $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
+ );
+
+ $self->{_attrs}{_sqlmaker_select_args} = $attrs->{_sqlmaker_select_args};
- return $sqlbind;
+ $aq;
}
=head2 find_or_new
=over 4
-=item Arguments: \%vals, \%attrs?
+=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
-=item Return Value: $rowobject
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
=back
{ artist => 'fred' }, { key => 'artists' });
$cd->cd_to_producer->find_or_new({ producer => $producer },
- { key => 'primary });
+ { key => 'primary' });
-Find an existing record from this resultset, based on its primary
-key, or a unique constraint. If none exists, instantiate a new result
-object and return it. The object will not be saved into your storage
-until you call L<DBIx::Class::Row/insert> on it.
+Find an existing record from this resultset using L</find>. if none exists,
+instantiate a new result object and return it. The object will not be saved
+into your storage until you call L<DBIx::Class::Row/insert> on it.
-You most likely want this method when looking for existing rows using
-a unique constraint that is not the primary key, or looking for
-related rows.
+You most likely want this method when looking for existing rows using a unique
+constraint that is not the primary key, or looking for related rows.
-If you want objects to be saved immediately, use L</find_or_create>
-instead.
+If you want objects to be saved immediately, use L</find_or_create> instead.
+
+B<Note>: Make sure to read the documentation of L</find> and understand the
+significance of the C<key> attribute, as its lack may skew your search, and
+subsequently result in spurious new objects.
B<Note>: Take care when using C<find_or_new> with a table having
columns with default values that you intend to be automatically
=over 4
-=item Arguments: \%vals
+=item Arguments: \%col_data
-=item Return Value: a L<DBIx::Class::Row> $object
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
=back
with an arbitrary depth and width, as long as the relationships actually
exists and the correct column data has been supplied.
-
Instead of hashrefs of plain related data (key/value pairs), you may
also pass new or inserted objects. New objects (not inserted yet, see
-L</new>), will be inserted into their appropriate tables.
+L</new_result>), will be inserted into their appropriate tables.
-Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
+Effectively a shortcut for C<< ->new_result(\%col_data)->insert >>.
Example of creating a new row.
);
Example of creating a new row and also creating a row in a related
-C<belongs_to>resultset. Note Hashref.
+C<belongs_to> resultset. Note Hashref.
$cd_rs->create({
title=>"Music for Silly Walks",
When subclassing ResultSet never attempt to override this method. Since
it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a
lot of the internals simply never call it, so your override will be
-bypassed more often than not. Override either L<new|DBIx::Class::Row/new>
-or L<insert|DBIx::Class::Row/insert> depending on how early in the
-L</create> process you need to intervene.
+bypassed more often than not. Override either L<DBIx::Class::Row/new>
+or L<DBIx::Class::Row/insert> depending on how early in the
+L</create> process you need to intervene. See also warning pertaining to
+L</new>.
=back
=cut
sub create {
- my ($self, $attrs) = @_;
+ my ($self, $col_data) = @_;
$self->throw_exception( "create needs a hashref" )
- unless ref $attrs eq 'HASH';
- return $self->new_result($attrs)->insert;
+ unless ref $col_data eq 'HASH';
+ return $self->new_result($col_data)->insert;
}
=head2 find_or_create
=over 4
-=item Arguments: \%vals, \%attrs?
+=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
-=item Return Value: $rowobject
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
=back
{ key => 'cd_artist_title' }
);
+B<Note>: Make sure to read the documentation of L</find> and understand the
+significance of the C<key> attribute, as its lack may skew your search, and
+subsequently result in spurious row creation.
+
B<Note>: Because find_or_create() reads from the database and then
possibly inserts based on the result, this method is subject to a race
condition. Another process could create a record in the table after
See also L</find> and L</update_or_create>. For information on how to declare
unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
+If you need to know if an existing row was found or a new one created use
+L</find_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
+to call L<DBIx::Class::Row/insert> to save the newly created row to the
+database!
+
+ my $cd = $schema->resultset('CD')->find_or_new({
+ cdid => 5,
+ artist => 'Massive Attack',
+ title => 'Mezzanine',
+ year => 2005,
+ });
+
+ if( !$cd->in_storage ) {
+ # do some stuff
+ $cd->insert;
+ }
+
=cut
sub find_or_create {
=over 4
-=item Arguments: \%col_values, { key => $unique_constraint }?
+=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
-=item Return Value: $rowobject
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
=back
$resultset->update_or_create({ col => $val, ... });
-First, searches for an existing row matching one of the unique constraints
-(including the primary key) on the source of this resultset. If a row is
-found, updates it with the other given column values. Otherwise, creates a new
-row.
+Like L</find_or_create>, but if a row is found it is immediately updated via
+C<< $found_row->update (\%col_data) >>.
+
Takes an optional C<key> attribute to search on a specific unique constraint.
For example:
producer => $producer,
name => 'harry',
}, {
- key => 'primary,
+ key => 'primary',
});
-
-If no C<key> is specified, it searches on all unique constraints defined on the
-source, including the primary key.
-
-If the C<key> is specified as C<primary>, it searches only on the primary key.
-
-See also L</find> and L</find_or_create>. For information on how to declare
-unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
+B<Note>: Make sure to read the documentation of L</find> and understand the
+significance of the C<key> attribute, as its lack may skew your search, and
+subsequently result in spurious row creation.
B<Note>: Take care when using C<update_or_create> with a table having
columns with default values that you intend to be automatically
In normal usage, the value of such columns should NOT be included at
all in the call to C<update_or_create>, even when set to C<undef>.
+See also L</find> and L</find_or_create>. For information on how to declare
+unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
+
+If you need to know if an existing row was updated or a new one created use
+L</update_or_new> and L<DBIx::Class::Row/in_storage> instead. Don't forget
+to call L<DBIx::Class::Row/insert> to save the newly created row to the
+database!
+
=cut
sub update_or_create {
=over 4
-=item Arguments: \%col_values, { key => $unique_constraint }?
+=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
-=item Return Value: $rowobject
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
=back
$resultset->update_or_new({ col => $val, ... });
-First, searches for an existing row matching one of the unique constraints
-(including the primary key) on the source of this resultset. If a row is
-found, updates it with the other given column values. Otherwise, instantiate
-a new result object and return it. The object will not be saved into your storage
-until you call L<DBIx::Class::Row/insert> on it.
+Like L</find_or_new> but if a row is found it is immediately updated via
+C<< $found_row->update (\%col_data) >>.
-Takes an optional C<key> attribute to search on a specific unique constraint.
For example:
# In your application
$cd->insert;
}
+B<Note>: Make sure to read the documentation of L</find> and understand the
+significance of the C<key> attribute, as its lack may skew your search, and
+subsequently result in spurious new objects.
+
B<Note>: Take care when using C<update_or_new> with a table having
columns with default values that you intend to be automatically
supplied by the database (e.g. an auto_increment primary key column).
=item Arguments: none
-=item Return Value: \@cache_objects?
+=item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass> | undef
=back
=over 4
-=item Arguments: \@cache_objects
+=item Arguments: L<\@result_objs|DBIx::Class::Manual::ResultClass>
-=item Return Value: \@cache_objects
+=item Return Value: L<\@result_objs|DBIx::Class::Manual::ResultClass>
=back
Sets the contents of the cache for the resultset. Expects an arrayref
of objects of the same class as those produced by the resultset. Note that
-if the cache is set the resultset will return the cached objects rather
+if the cache is set, the resultset will return the cached objects rather
than re-querying the database even if the cache attr is not set.
The contents of the cache can also be populated by using the
=item Arguments: none
-=item Return Value: []
+=item Return Value: undef
=back
sub is_ordered {
my ($self) = @_;
- return scalar $self->result_source->storage->_parse_order_by($self->{attrs}{order_by});
+ return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
}
=head2 related_resultset
=over 4
-=item Arguments: $relationship_name
+=item Arguments: $rel_name
-=item Return Value: $resultset
+=item Return Value: L<$resultset|/search>
=back
sub related_resultset {
my ($self, $rel) = @_;
- $self->{related_resultsets} ||= {};
- return $self->{related_resultsets}{$rel} ||= do {
+ return $self->{related_resultsets}{$rel}
+ if defined $self->{related_resultsets}{$rel};
+
+ return $self->{related_resultsets}{$rel} = do {
my $rsrc = $self->result_source;
my $rel_info = $rsrc->relationship_info($rel);
# (the select/as attrs were deleted in the beginning), we need to flip all
# left joins to inner, so we get the expected results
# read the comment on top of the actual function to see what this does
- $attrs->{from} = $rsrc->schema->storage->_straight_join_to_node ($attrs->{from}, $alias);
+ $attrs->{from} = $rsrc->schema->storage->_inner_join_to_node ($attrs->{from}, $alias);
#XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
delete @{$attrs}{qw(result_class alias)};
- my $new_cache;
-
- if (my $cache = $self->get_cache) {
- if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
- $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
- @$cache ];
- }
- }
-
my $rel_source = $rsrc->related_source($rel);
my $new = do {
where => $attrs->{where},
});
};
- $new->set_cache($new_cache) if $new_cache;
+
+ if (my $cache = $self->get_cache) {
+ my @related_cache = map
+ { @{$_->related_resultset($rel)->get_cache||[]} }
+ @$cache
+ ;
+
+ $new->set_cache(\@related_cache) if @related_cache;
+ }
+
$new;
};
}
my $me = $self->current_source_alias;
- return $self->search(
+ return $self->search({
"$me.modified" => $user->id,
- );
+ });
}
=cut
sub current_source_alias {
- my ($self) = @_;
-
- return ($self->{attrs} || {})->{alias} || 'me';
+ return (shift->{attrs} || {})->{alias} || 'me';
}
=head2 as_subselect_rs
=item Arguments: none
-=item Return Value: $resultset
+=item Return Value: L<$resultset|/search>
=back
=cut
sub as_subselect_rs {
- my $self = shift;
+ my $self = shift;
+
+ my $attrs = $self->_resolved_attrs;
+
+ my $fresh_rs = (ref $self)->new (
+ $self->result_source
+ );
- return $self->result_source->resultset->search( undef, {
- alias => $self->current_source_alias,
- from => [{
- $self->current_source_alias => $self->as_query,
- -alias => $self->current_source_alias,
- -source_handle => $self->result_source->handle,
- }]
- });
+ # these pieces will be locked in the subquery
+ delete $fresh_rs->{cond};
+ delete @{$fresh_rs->{attrs}}{qw/where bind/};
+
+ return $fresh_rs->search( {}, {
+ from => [{
+ $attrs->{alias} => $self->as_query,
+ -alias => $attrs->{alias},
+ -rsrc => $self->result_source,
+ }],
+ alias => $attrs->{alias},
+ });
}
# This code is called by search_related, and makes sure there
# we need to take the prefetch the attrs into account before we
# ->_resolve_join as otherwise they get lost - captainL
- my $join = $self->_merge_attr( $attrs->{join}, $attrs->{prefetch} );
+ my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
- delete @{$attrs}{qw/join prefetch collapse distinct select as columns +select +as +columns/};
+ delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
# are resolved (prefetch is useless - we are wrapping
# a subquery anyway).
my $rs_copy = $self->search;
- $rs_copy->{attrs}{join} = $self->_merge_attr (
+ $rs_copy->{attrs}{join} = $self->_merge_joinpref_attr (
$rs_copy->{attrs}{join},
delete $rs_copy->{attrs}{prefetch},
);
$from = [{
- -source_handle => $source->handle,
- -alias => $attrs->{alias},
+ -rsrc => $source,
+ -alias => $attrs->{alias},
$attrs->{alias} => $rs_copy->as_query,
}];
- delete @{$attrs}{@force_subq_attrs, 'where'};
+ delete @{$attrs}{@force_subq_attrs, qw/where bind/};
$seen->{-relation_chain_depth} = 0;
}
elsif ($attrs->{from}) { #shallow copy suffices
}
else {
$from = [{
- -source_handle => $source->handle,
+ -rsrc => $source,
-alias => $attrs->{alias},
$attrs->{alias} => $source->from,
}];
return {%$attrs, from => $from, seen_join => $seen};
}
-# too many times we have to do $attrs = { %{$self->_resolved_attrs} }
-sub _resolved_attrs_copy {
- my $self = shift;
- return { %{$self->_resolved_attrs (@_)} };
-}
-
sub _resolved_attrs {
my $self = shift;
return $self->{_attrs} if $self->{_attrs};
my $source = $self->result_source;
my $alias = $attrs->{alias};
- $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
- my @colbits;
+ # default selection list
+ $attrs->{columns} = [ $source->columns ]
+ unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
- # build columns (as long as select isn't set) into a set of as/select hashes
- unless ( $attrs->{select} ) {
-
- my @cols;
- if ( ref $attrs->{columns} eq 'ARRAY' ) {
- @cols = @{ delete $attrs->{columns}}
- } elsif ( defined $attrs->{columns} ) {
- @cols = delete $attrs->{columns}
- } else {
- @cols = $source->columns
- }
-
- for (@cols) {
- if ( ref $_ eq 'HASH' ) {
- push @colbits, $_
- } else {
- my $key = /^\Q${alias}.\E(.+)$/
- ? "$1"
- : "$_";
- my $value = /\./
- ? "$_"
- : "${alias}.$_";
- push @colbits, { $key => $value };
- }
- }
+ # merge selectors together
+ for (qw/columns select as/) {
+ $attrs->{$_} = $self->_merge_attr($attrs->{$_}, delete $attrs->{"+$_"})
+ if $attrs->{$_} or $attrs->{"+$_"};
}
- # add the additional columns on
- foreach (qw{include_columns +columns}) {
- if ( $attrs->{$_} ) {
- my @list = ( ref($attrs->{$_}) eq 'ARRAY' )
- ? @{ delete $attrs->{$_} }
- : delete $attrs->{$_};
- for (@list) {
- if ( ref($_) eq 'HASH' ) {
- push @colbits, $_
- } else {
- my $key = ( split /\./, $_ )[-1];
- my $value = ( /\./ ? $_ : "$alias.$_" );
- push @colbits, { $key => $value };
+ # disassemble columns
+ my (@sel, @as);
+ if (my $cols = delete $attrs->{columns}) {
+ for my $c (ref $cols eq 'ARRAY' ? @$cols : $cols) {
+ if (ref $c eq 'HASH') {
+ for my $as (sort keys %$c) {
+ push @sel, $c->{$as};
+ push @as, $as;
}
}
+ else {
+ push @sel, $c;
+ push @as, $c;
+ }
}
}
- # start with initial select items
- if ( $attrs->{select} ) {
- $attrs->{select} =
- ( ref $attrs->{select} eq 'ARRAY' )
- ? [ @{ $attrs->{select} } ]
- : [ $attrs->{select} ];
-
- if ( $attrs->{as} ) {
- $attrs->{as} =
- (
- ref $attrs->{as} eq 'ARRAY'
- ? [ @{ $attrs->{as} } ]
- : [ $attrs->{as} ]
- )
- } else {
- $attrs->{as} = [ map {
- m/^\Q${alias}.\E(.+)$/
- ? $1
- : $_
- } @{ $attrs->{select} }
- ]
+ # when trying to weed off duplicates later do not go past this point -
+ # everything added from here on is unbalanced "anyone's guess" stuff
+ my $dedup_stop_idx = $#as;
+
+ push @as, @{ ref $attrs->{as} eq 'ARRAY' ? $attrs->{as} : [ $attrs->{as} ] }
+ if $attrs->{as};
+ push @sel, @{ ref $attrs->{select} eq 'ARRAY' ? $attrs->{select} : [ $attrs->{select} ] }
+ if $attrs->{select};
+
+ # assume all unqualified selectors to apply to the current alias (legacy stuff)
+ $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
+
+ # disqualify all $alias.col as-bits (inflate-map mandated)
+ $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
+
+ # de-duplicate the result (remove *identical* select/as pairs)
+ # and also die on duplicate {as} pointing to different {select}s
+ # not using a c-style for as the condition is prone to shrinkage
+ my $seen;
+ my $i = 0;
+ while ($i <= $dedup_stop_idx) {
+ if ($seen->{"$sel[$i] \x00\x00 $as[$i]"}++) {
+ splice @sel, $i, 1;
+ splice @as, $i, 1;
+ $dedup_stop_idx--;
+ }
+ elsif ($seen->{$as[$i]}++) {
+ $self->throw_exception(
+ "inflate_result() alias '$as[$i]' specified twice with different SQL-side {select}-ors"
+ );
+ }
+ else {
+ $i++;
}
}
- else {
- # otherwise we intialise select & as to empty
- $attrs->{select} = [];
- $attrs->{as} = [];
- }
-
- # now add colbits to select/as
- push @{ $attrs->{select} }, map values %{$_}, @colbits;
- push @{ $attrs->{as} }, map keys %{$_}, @colbits;
- if ( my $adds = delete $attrs->{'+select'} ) {
- $adds = [$adds] unless ref $adds eq 'ARRAY';
- push @{ $attrs->{select} },
- map { /\./ || ref $_ ? $_ : "$alias.$_" } @$adds;
- }
- if ( my $adds = delete $attrs->{'+as'} ) {
- $adds = [$adds] unless ref $adds eq 'ARRAY';
- push @{ $attrs->{as} }, @$adds;
- }
+ $attrs->{select} = \@sel;
+ $attrs->{as} = \@as;
$attrs->{from} ||= [{
- -source_handle => $source->handle,
- -alias => $self->{attrs}{alias},
+ -rsrc => $source,
+ -alias => $self->{attrs}{alias},
$self->{attrs}{alias} => $source->from,
}];
$self->throw_exception ('join/prefetch can not be used with a custom {from}')
if ref $attrs->{from} ne 'ARRAY';
- my $join = delete $attrs->{join} || {};
+ my $join = (delete $attrs->{join}) || {};
if ( defined $attrs->{prefetch} ) {
- $join = $self->_merge_attr( $join, $attrs->{prefetch} );
+ $join = $self->_merge_joinpref_attr( $join, $attrs->{prefetch} );
}
$attrs->{from} = # have to copy here to avoid corrupting the original
# subquery (since a group_by is present)
if (delete $attrs->{distinct}) {
if ($attrs->{group_by}) {
- carp ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
+ carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
}
else {
- $attrs->{group_by} = [ grep { !ref($_) || (ref($_) ne 'HASH') } @{$attrs->{select}} ];
-
- # add any order_by parts that are not already present in the group_by
- # we need to be careful not to add any named functions/aggregates
- # i.e. select => [ ... { count => 'foo', -as 'foocount' } ... ]
- my %already_grouped = map { $_ => 1 } (@{$attrs->{group_by}});
-
- my $storage = $self->result_source->schema->storage;
-
- my $rs_column_list = $storage->_resolve_column_info ($attrs->{from});
-
- for my $chunk ($storage->_parse_order_by($attrs->{order_by})) {
- if ($rs_column_list->{$chunk} && not $already_grouped{$chunk}++) {
- push @{$attrs->{group_by}}, $chunk;
- }
- }
+ $attrs->{_grouped_by_distinct} = 1;
+ # distinct affects only the main selection part, not what prefetch may
+ # add below.
+ $attrs->{group_by} = $source->storage->_group_over_selection($attrs);
}
}
# generate selections based on the prefetch helper
- if ( my $prefetch = delete $attrs->{prefetch} ) {
+ my $prefetch;
+ $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
+ if defined $attrs->{prefetch};
+
+ if ($prefetch) {
+
+ $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
+ if $attrs->{_dark_selector};
+
$attrs->{collapse} = 1;
# this is a separate structure (we don't look in {from} directly)
my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
- # we need to somehow mark which columns came from prefetch
- $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
-
- push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
+ push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
}
+ if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
+ $attrs->{_related_results_construction} = 1;
+ }
+
# run through the resulting joinstructure (starting from our current slot)
# and unset collapse if proven unnesessary
- if ($attrs->{collapse} && ref $attrs->{from} eq 'ARRAY') {
+ #
+ # also while we are at it find out if the current root source has
+ # been premultiplied by previous related_source chaining
+ #
+ # this allows to predict whether a root object with all other relation
+ # data set to NULL is in fact unique
+ if ($attrs->{collapse}) {
- if (@{$attrs->{from}} > 1) {
+ if (ref $attrs->{from} eq 'ARRAY') {
- # find where our table-spec starts and consider only things after us
- my @fromlist = @{$attrs->{from}};
- while (@fromlist) {
- my $t = shift @fromlist;
- $t = $t->[0] if ref $t eq 'ARRAY'; #me vs join from-spec mismatch
- last if ($t->{-alias} && $t->{-alias} eq $alias);
+ if (@{$attrs->{from}} == 1) {
+ # no joins - no collapse
+ $attrs->{collapse} = 0;
}
+ else {
+ # find where our table-spec starts
+ my @fromlist = @{$attrs->{from}};
+ while (@fromlist) {
+ my $t = shift @fromlist;
+
+ my $is_multi;
+ # me vs join from-spec distinction - a ref means non-root
+ if (ref $t eq 'ARRAY') {
+ $t = $t->[0];
+ $is_multi ||= ! $t->{-is_single};
+ }
+ last if ($t->{-alias} && $t->{-alias} eq $alias);
+ $attrs->{_main_source_premultiplied} ||= $is_multi;
+ }
- for (@fromlist) {
- $attrs->{collapse} = ! $_->[0]{-is_single}
- and last;
+ # no non-singles remaining, nor any premultiplication - nothing to collapse
+ if (
+ ! $attrs->{_main_source_premultiplied}
+ and
+ ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
+ ) {
+ $attrs->{collapse} = 0;
+ }
}
}
+
else {
- # no joins - no collapse
- $attrs->{collapse} = 0;
+ # if we can not analyze the from - err on the side of safety
+ $attrs->{_main_source_premultiplied} = 1;
}
}
}
}
-sub _merge_attr {
+sub _merge_joinpref_attr {
my ($self, $orig, $import) = @_;
return $import unless defined($orig);
$position++;
}
my ($import_key) = ( ref $import_element eq 'HASH' ) ? keys %{$import_element} : ($import_element);
+ $import_key = '' if not defined $import_key;
if ($best_candidate->{score} == 0 || exists $seen_keys->{$import_key}) {
push( @{$orig}, $import_element );
$orig->[$best_candidate->{position}] = $import_element;
} elsif (ref $import_element eq 'HASH') {
my ($key) = keys %{$orig_best};
- $orig->[$best_candidate->{position}] = { $key => $self->_merge_attr($orig_best->{$key}, $import_element->{$key}) };
+ $orig->[$best_candidate->{position}] = { $key => $self->_merge_joinpref_attr($orig_best->{$key}, $import_element->{$key}) };
}
}
$seen_keys->{$import_key} = 1; # don't merge the same key twice
}
- return $orig;
+ return @$orig ? $orig : ();
}
-sub result_source {
- my $self = shift;
+{
+ my $hm;
- if (@_) {
- $self->_source_handle($_[0]->handle);
- } else {
- $self->_source_handle->resolve;
- }
+ sub _merge_attr {
+ $hm ||= do {
+ require Hash::Merge;
+ my $hm = Hash::Merge->new;
+
+ $hm->specify_behavior({
+ SCALAR => {
+ SCALAR => sub {
+ my ($defl, $defr) = map { defined $_ } (@_[0,1]);
+
+ if ($defl xor $defr) {
+ return [ $defl ? $_[0] : $_[1] ];
+ }
+ elsif (! $defl) {
+ return [];
+ }
+ elsif (__HM_DEDUP and $_[0] eq $_[1]) {
+ return [ $_[0] ];
+ }
+ else {
+ return [$_[0], $_[1]];
+ }
+ },
+ ARRAY => sub {
+ return $_[1] if !defined $_[0];
+ return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
+ return [$_[0], @{$_[1]}]
+ },
+ HASH => sub {
+ return [] if !defined $_[0] and !keys %{$_[1]};
+ return [ $_[1] ] if !defined $_[0];
+ return [ $_[0] ] if !keys %{$_[1]};
+ return [$_[0], $_[1]]
+ },
+ },
+ ARRAY => {
+ SCALAR => sub {
+ return $_[0] if !defined $_[1];
+ return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
+ return [@{$_[0]}, $_[1]]
+ },
+ ARRAY => sub {
+ my @ret = @{$_[0]} or return $_[1];
+ return [ @ret, @{$_[1]} ] unless __HM_DEDUP;
+ my %idx = map { $_ => 1 } @ret;
+ push @ret, grep { ! defined $idx{$_} } (@{$_[1]});
+ \@ret;
+ },
+ HASH => sub {
+ return [ $_[1] ] if ! @{$_[0]};
+ return $_[0] if !keys %{$_[1]};
+ return $_[0] if __HM_DEDUP and List::Util::first { $_ eq $_[1] } @{$_[0]};
+ return [ @{$_[0]}, $_[1] ];
+ },
+ },
+ HASH => {
+ SCALAR => sub {
+ return [] if !keys %{$_[0]} and !defined $_[1];
+ return [ $_[0] ] if !defined $_[1];
+ return [ $_[1] ] if !keys %{$_[0]};
+ return [$_[0], $_[1]]
+ },
+ ARRAY => sub {
+ return [] if !keys %{$_[0]} and !@{$_[1]};
+ return [ $_[0] ] if !@{$_[1]};
+ return $_[1] if !keys %{$_[0]};
+ return $_[1] if __HM_DEDUP and List::Util::first { $_ eq $_[0] } @{$_[1]};
+ return [ $_[0], @{$_[1]} ];
+ },
+ HASH => sub {
+ return [] if !keys %{$_[0]} and !keys %{$_[1]};
+ return [ $_[0] ] if !keys %{$_[1]};
+ return [ $_[1] ] if !keys %{$_[0]};
+ return [ $_[0] ] if $_[0] eq $_[1];
+ return [ $_[0], $_[1] ];
+ },
+ }
+ } => 'DBIC_RS_ATTR_MERGER');
+ $hm;
+ };
+
+ return $hm->merge ($_[1], $_[2]);
+ }
+}
+
+sub STORABLE_freeze {
+ my ($self, $cloning) = @_;
+ my $to_serialize = { %$self };
+
+ # A cursor in progress can't be serialized (and would make little sense anyway)
+ # the parser can be regenerated (and can't be serialized)
+ delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
+
+ # nor is it sensical to store a not-yet-fired-count pager
+ if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
+ delete $to_serialize->{pager};
+ }
+
+ Storable::nfreeze($to_serialize);
}
+# need this hook for symmetry
+sub STORABLE_thaw {
+ my ($self, $cloning, $serialized) = @_;
+
+ %$self = %{ Storable::thaw($serialized) };
+
+ $self;
+}
+
+
=head2 throw_exception
See L<DBIx::Class::Schema/throw_exception> for details.
sub throw_exception {
my $self=shift;
- if (ref $self && $self->_source_handle->schema) {
- $self->_source_handle->schema->throw_exception(@_)
+ if (ref $self and my $rsrc = $self->result_source) {
+ $rsrc->throw_exception(@_)
}
else {
DBIx::Class::Exception->throw(@_);
}
}
+1;
+
+__END__
+
# XXX: FIXME: Attributes docs need clearing up
=head1 ATTRIBUTES
C<\%attrs> argument. See L</search>, L</search_rs>, L</find>,
L</count>.
+Default attributes can be set on the result class using
+L<DBIx::Class::ResultSource/resultset_attributes>. (Please read
+the CAVEATS on that feature before using it!)
+
These are in no particular order:
=head2 order_by
=over 4
-=item Value: \@columns
+=item Value: \@columns | \%columns | $column
=back
expression). Adds C<me.> onto the start of any column without a C<.> in
it and sets C<select> from that, then auto-populates C<as> from
C<select> as normal. (You may also use the C<cols> attribute, as in
-earlier versions of DBIC.)
+earlier versions of DBIC, but this is deprecated.)
+
+Essentially C<columns> does the same as L</select> and L</as>.
+
+ columns => [ 'foo', { bar => 'baz' } ]
+
+is the same as
+
+ select => [qw/foo baz/],
+ as => [qw/foo bar/]
=head2 +columns
=back
-Indicates additional columns to be selected from storage. Works the same
-as L</columns> but adds columns to the selection. (You may also use the
-C<include_columns> attribute, as in earlier versions of DBIC). For
-example:-
+Indicates additional columns to be selected from storage. Works the same as
+L</columns> but adds columns to the selection. (You may also use the
+C<include_columns> attribute, as in earlier versions of DBIC, but this is
+deprecated). For example:-
$schema->resultset('CD')->search(undef, {
'+columns' => ['artist.name'],
column (or relationship) accessor, and 'name' is the name of the column
accessor in the related table.
+B<NOTE:> You need to explicitly quote '+columns' when defining the attribute.
+Not doing so causes Perl to incorrectly interpret +columns as a bareword with a
+unary plus operator before it.
+
=head2 include_columns
=over 4
select => [
'name',
{ count => 'employeeid' },
- { sum => 'salary' }
+ { max => { length => 'name' }, -as => 'longest_name' }
]
});
-When you use function/stored procedure names and do not supply an C<as>
-attribute, the column names returned are storage-dependent. E.g. MySQL would
-return a column named C<count(employeeid)> in the above example.
+ # Equivalent SQL
+ SELECT name, COUNT( employeeid ), MAX( LENGTH( name ) ) AS longest_name FROM employee
+
+B<NOTE:> You will almost always need a corresponding L</as> attribute when you
+use L</select>, to instruct DBIx::Class how to store the result of the column.
+Also note that the L</as> attribute has nothing to do with the SQL-side 'AS'
+identifier aliasing. You can however alias a function, so you can use it in
+e.g. an C<ORDER BY> clause. This is done via the C<-as> B<select function
+attribute> supplied as shown in the example above.
-B<NOTE:> You will almost always need a corresponding 'as' entry when you use
-'select'.
+B<NOTE:> You need to explicitly quote '+select'/'+as' when defining the attributes.
+Not doing so causes Perl to incorrectly interpret them as a bareword with a
+unary plus operator before it.
=head2 +select
=over 4
Indicates additional columns to be selected from storage. Works the same as
-L</select> but adds columns to the selection.
-
-=back
-
-=head2 +as
-
-=over 4
-
-Indicates additional column names for those added via L</+select>. See L</as>.
+L</select> but adds columns to the default selection, instead of specifying
+an explicit list.
=back
=back
-Indicates column names for object inflation. That is, C<as>
-indicates the name that the column can be accessed as via the
-C<get_column> method (or via the object accessor, B<if one already
-exists>). It has nothing to do with the SQL code C<SELECT foo AS bar>.
-
-The C<as> attribute is used in conjunction with C<select>,
-usually when C<select> contains one or more function or stored
-procedure names:
+Indicates column names for object inflation. That is L</as> indicates the
+slot name in which the column value will be stored within the
+L<Row|DBIx::Class::Row> object. The value will then be accessible via this
+identifier by the C<get_column> method (or via the object accessor B<if one
+with the same name already exists>) as shown below. The L</as> attribute has
+B<nothing to do> with the SQL-side C<AS>. See L</select> for details.
$rs = $schema->resultset('Employee')->search(undef, {
select => [
'name',
- { count => 'employeeid' }
+ { count => 'employeeid' },
+ { max => { length => 'name' }, -as => 'longest_name' }
],
- as => ['name', 'employee_count'],
+ as => [qw/
+ name
+ employee_count
+ max_name_length
+ /],
});
- my $employee = $rs->first(); # get the first Employee
-
If the object against which the search is performed already has an accessor
matching a column name specified in C<as>, the value can be retrieved using
the accessor as normal:
You can create your own accessors if required - see
L<DBIx::Class::Manual::Cookbook> for details.
-Please note: This will NOT insert an C<AS employee_count> into the SQL
-statement produced, it is used for internal access only. Thus
-attempting to use the accessor in an C<order_by> clause or similar
-will fail miserably.
+=head2 +as
+
+=over 4
-To get around this limitation, you can supply literal SQL to your
-C<select> attribute that contains the C<AS alias> text, e.g.
+Indicates additional column names for those added via L</+select>. See L</as>.
- select => [\'myfield AS alias']
+=back
=head2 join
will return a set of all artists that have both a cd with title 'Down
to Earth' and a cd with title 'Popular'.
-If you want to fetch related objects from other tables as well, see C<prefetch>
+If you want to fetch related objects from other tables as well, see L</prefetch>
below.
+ NOTE: An internal join-chain pruner will discard certain joins while
+ constructing the actual SQL query, as long as the joins in question do not
+ affect the retrieved result. This for example includes 1:1 left joins
+ that are not part of the restriction specification (WHERE/HAVING) nor are
+ a part of the query selection.
+
For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
-=head2 prefetch
+=head2 collapse
=over 4
-=item Value: ($rel_name | \@rel_names | \%rel_names)
+=item Value: (0 | 1)
=back
-Contains one or more relationships that should be fetched along with
-the main query (when they are accessed afterwards the data will
-already be available, without extra queries to the database). This is
-useful for when you know you will need the related objects, because it
-saves at least one query:
-
- my $rs = $schema->resultset('Tag')->search(
- undef,
- {
- prefetch => {
- cd => 'artist'
- }
- }
- );
+When set to a true value, indicates that any rows fetched from joined has_many
+relationships are to be aggregated into the corresponding "parent" object. For
+example, the resultset:
-The initial search results in SQL like the following:
+ my $rs = $schema->resultset('CD')->search({}, {
+ '+columns' => [ qw/ tracks.title tracks.position / ],
+ join => 'tracks',
+ collapse => 1,
+ });
- SELECT tag.*, cd.*, artist.* FROM tag
- JOIN cd ON tag.cd = cd.cdid
- JOIN artist ON cd.artist = artist.artistid
+While executing the following query:
-L<DBIx::Class> has no need to go back to the database when we access the
-C<cd> or C<artist> relationships, which saves us two SQL statements in this
-case.
+ SELECT me.*, tracks.title, tracks.position
+ FROM cd me
+ LEFT JOIN track tracks
+ ON tracks.cdid = me.cdid
-Simple prefetches will be joined automatically, so there is no need
-for a C<join> attribute in the above search.
+Will return only as many objects as there are rows in the CD source, even
+though the result of the query may span many rows. Each of these CD objects
+will in turn have multiple "Track" objects hidden behind the has_many
+generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
+of this resultset would be as many CD objects as there are tracks (a "Cartesian
+product"), with each CD object containing exactly one of all fetched Track data.
-C<prefetch> can be used with the following relationship types: C<belongs_to>,
-C<has_one> (or if you're using C<add_relationship>, any relationship declared
-with an accessor type of 'single' or 'filter'). A more complex example that
-prefetches an artists cds, the tracks on those cds, and the tags associated
-with that artist is given below (assuming many-to-many from artists to tags):
+When a collapse is requested on a non-ordered resultset, an order by some
+unique part of the main source (the left-most table) is inserted automatically.
+This is done so that the resultset is allowed to be "lazy" - calling
+L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
+object with all of its related data.
- my $rs = $schema->resultset('Artist')->search(
- undef,
- {
- prefetch => [
- { cds => 'tracks' },
- { artist_tags => 'tags' }
- ]
- }
- );
+If an L</order_by> is already declared, and orders the resultset in a way that
+makes collapsing as described above impossible (e.g. C<< ORDER BY
+has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
+switch to "eager" mode and slurp the entire resultset before consturcting the
+first object returned by L</next>.
+Setting this attribute on a resultset that does not join any has_many
+relations is a no-op.
-B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
-attributes will be ignored.
+For a more in-depth discussion, see L</PREFETCHING>.
-B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
-exactly as you might expect.
+=head2 prefetch
=over 4
-=item *
+=item Value: ($rel_name | \@rel_names | \%rel_names)
-Prefetch uses the L</cache> to populate the prefetched relationships. This
-may or may not be what you want.
+=back
-=item *
+This attribute is a shorthand for specifying a L</join> spec, adding all
+columns from the joined related sources as L</+columns> and setting
+L</collapse> to a true value. For example, the following two queries are
+equivalent:
-If you specify a condition on a prefetched relationship, ONLY those
-rows that match the prefetched condition will be fetched into that relationship.
-This means that adding prefetch to a search() B<may alter> what is returned by
-traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
+ my $rs = $schema->resultset('Artist')->search({}, {
+ prefetch => { cds => ['genre', 'tracks' ] },
+ });
- my $artist_rs = $schema->resultset('Artist')->search({
- 'cds.year' => 2008,
- }, {
- join => 'cds',
+and
+
+ my $rs = $schema->resultset('Artist')->search({}, {
+ join => { cds => ['genre', 'tracks' ] },
+ collapse => 1,
+ '+columns' => [
+ (map
+ { +{ "cds.$_" => "cds.$_" } }
+ $schema->source('Artist')->related_source('cds')->columns
+ ),
+ (map
+ { +{ "cds.genre.$_" => "genre.$_" } }
+ $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
+ ),
+ (map
+ { +{ "cds.tracks.$_" => "tracks.$_" } }
+ $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
+ ),
+ ],
});
- my $count = $artist_rs->first->cds->count;
+Both producing the following SQL:
+
+ SELECT me.artistid, me.name, me.rank, me.charfield,
+ cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
+ genre.genreid, genre.name,
+ tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
+ FROM artist me
+ LEFT JOIN cd cds
+ ON cds.artist = me.artistid
+ LEFT JOIN genre genre
+ ON genre.genreid = cds.genreid
+ LEFT JOIN track tracks
+ ON tracks.cd = cds.cdid
+ ORDER BY me.artistid
+
+While L</prefetch> implies a L</join>, it is ok to mix the two together, as
+the arguments are properly merged and generally do the right thing. For
+example, you may want to do the following:
+
+ my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
+ { 'genre.genreid' => undef },
+ {
+ join => { cds => 'genre' },
+ prefetch => 'cds',
+ }
+ );
- my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
+Which generates the following SQL:
- my $prefetch_count = $artist_rs_prefetch->first->cds->count;
+ SELECT me.artistid, me.name, me.rank, me.charfield,
+ cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
+ FROM artist me
+ LEFT JOIN cd cds
+ ON cds.artist = me.artistid
+ LEFT JOIN genre genre
+ ON genre.genreid = cds.genreid
+ WHERE genre.genreid IS NULL
+ ORDER BY me.artistid
- cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
+For a more in-depth discussion, see L</PREFETCHING>.
+
+=head2 alias
-that cmp_ok() may or may not pass depending on the datasets involved. This
-behavior may or may not survive the 0.09 transition.
+=over 4
+
+=item Value: $source_alias
=back
+Sets the source alias for the query. Normally, this defaults to C<me>, but
+nested search queries (sub-SELECTs) might need specific aliases set to
+reference inner queries. For example:
+
+ my $q = $rs
+ ->related_resultset('CDs')
+ ->related_resultset('Tracks')
+ ->search({
+ 'track.id' => { -ident => 'none_search.id' },
+ })
+ ->as_query;
+
+ my $ids = $self->search({
+ -not_exists => $q,
+ }, {
+ alias => 'none_search',
+ group_by => 'none_search.id',
+ })->get_column('id')->as_query;
+
+ $self->search({ id => { -in => $ids } })
+
+This attribute is directly tied to L</current_source_alias>.
+
=head2 page
=over 4
identical to creating a non-pages resultset and then calling ->page($page)
on it.
-If L<rows> attribute is not specified it defaults to 10 rows per page.
+If L</rows> attribute is not specified it defaults to 10 rows per page.
When you have a paged resultset, L</count> will only return the number
of rows in the page. To get the total, use the L</pager> and call
Specifies the (zero-based) row number for the first row to be returned, or the
of the first row of the first page if paging is used.
+=head2 software_limit
+
+=over 4
+
+=item Value: (0 | 1)
+
+=back
+
+When combined with L</rows> and/or L</offset> the generated SQL will not
+include any limit dialect stanzas. Instead the entire result will be selected
+as if no limits were specified, and DBIC will perform the limit locally, by
+artificially advancing and finishing the resulting L</cursor>.
+
+This is the recommended way of performing resultset limiting when no sane RDBMS
+implementation is available (e.g.
+L<Sybase ASE|DBIx::Class::Storage::DBI::Sybase::ASE> using the
+L<Generic Sub Query|DBIx::Class::SQLMaker::LimitDialects/GenericSubQ> hack)
+
=head2 group_by
=over 4
ORDER BY. It is applied to the after the grouping calculations have been
done.
- having => { 'count(employee)' => { '>=', 100 } }
+ having => { 'count_employee' => { '>=', 100 } }
+
+or with an in-place function in which case literal SQL is required:
+
+ having => \[ 'count(employee) >= ?', [ count => 100 ] ]
=head2 distinct
Adds to the WHERE clause.
# only return rows WHERE deleted IS NULL for all searches
- __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); )
+ __PACKAGE__->resultset_attributes({ where => { deleted => undef } });
Can be overridden by passing C<< { where => undef } >> as an attribute
to a resultset.
+For more complicated where clauses see L<SQL::Abstract/WHERE CLAUSES>.
+
=back
=head2 cache
=over 4
-=item Value: ( 'update' | 'shared' )
+=item Value: ( 'update' | 'shared' | \$scalar )
=back
Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT
-... FOR SHARED.
+... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
+query.
-=cut
+=head1 PREFETCHING
+
+DBIx::Class supports arbitrary related data prefetching from multiple related
+sources. Any combination of relationship types and column sets are supported.
+If L<collapsing|/collapse> is requested, there is an additional requirement of
+selecting enough data to make every individual object uniquely identifiable.
+
+Here are some more involved examples, based on the following relationship map:
+
+ # Assuming:
+ My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
+ My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
+ My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
+
+ My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
+
+ My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
+
+
+
+ my $rs = $schema->resultset('Tag')->search(
+ undef,
+ {
+ prefetch => {
+ cd => 'artist'
+ }
+ }
+ );
+
+The initial search results in SQL like the following:
+
+ SELECT tag.*, cd.*, artist.* FROM tag
+ JOIN cd ON tag.cd = cd.cdid
+ JOIN artist ON cd.artist = artist.artistid
+
+L<DBIx::Class> has no need to go back to the database when we access the
+C<cd> or C<artist> relationships, which saves us two SQL statements in this
+case.
+
+Simple prefetches will be joined automatically, so there is no need
+for a C<join> attribute in the above search.
+
+The L</prefetch> attribute can be used with any of the relationship types
+and multiple prefetches can be specified together. Below is a more complex
+example that prefetches a CD's artist, its liner notes (if present),
+the cover image, the tracks on that CD, and the guests on those
+tracks.
+
+ my $rs = $schema->resultset('CD')->search(
+ undef,
+ {
+ prefetch => [
+ { artist => 'record_label'}, # belongs_to => belongs_to
+ 'liner_note', # might_have
+ 'cover_image', # has_one
+ { tracks => 'guests' }, # has_many => has_many
+ ]
+ }
+ );
+
+This will produce SQL like the following:
+
+ SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
+ tracks.*, guests.*
+ FROM cd me
+ JOIN artist artist
+ ON artist.artistid = me.artistid
+ JOIN record_label record_label
+ ON record_label.labelid = artist.labelid
+ LEFT JOIN track tracks
+ ON tracks.cdid = me.cdid
+ LEFT JOIN guest guests
+ ON guests.trackid = track.trackid
+ LEFT JOIN liner_notes liner_note
+ ON liner_note.cdid = me.cdid
+ JOIN cd_artwork cover_image
+ ON cover_image.cdid = me.cdid
+ ORDER BY tracks.cd
+
+Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
+C<tracks>, and C<guests> of the CD will all be available through the
+relationship accessors without the need for additional queries to the
+database.
+
+=head3 CAVEATS
+
+Prefetch does a lot of deep magic. As such, it may not behave exactly
+as you might expect.
+
+=over 4
+
+=item *
+
+Prefetch uses the L</cache> to populate the prefetched relationships. This
+may or may not be what you want.
+
+=item *
+
+If you specify a condition on a prefetched relationship, ONLY those
+rows that match the prefetched condition will be fetched into that relationship.
+This means that adding prefetch to a search() B<may alter> what is returned by
+traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
+
+ my $artist_rs = $schema->resultset('Artist')->search({
+ 'cds.year' => 2008,
+ }, {
+ join => 'cds',
+ });
+
+ my $count = $artist_rs->first->cds->count;
+
+ my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
+
+ my $prefetch_count = $artist_rs_prefetch->first->cds->count;
+
+ cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
+
+That cmp_ok() may or may not pass depending on the datasets involved. In other
+words the C<WHERE> condition would apply to the entire dataset, just like
+it would in regular SQL. If you want to add a condition only to the "right side"
+of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
+condition|DBIx::Class::Relationship::Base/condition>
+
+=back
+
+=head1 DBIC BIND VALUES
+
+Because DBIC may need more information to bind values than just the column name
+and value itself, it uses a special format for both passing and receiving bind
+values. Each bind value should be composed of an arrayref of
+C<< [ \%args => $val ] >>. The format of C<< \%args >> is currently:
+
+=over 4
+
+=item dbd_attrs
+
+If present (in any form), this is what is being passed directly to bind_param.
+Note that different DBD's expect different bind args. (e.g. DBD::SQLite takes
+a single numerical type, while DBD::Pg takes a hashref if bind options.)
+
+If this is specified, all other bind options described below are ignored.
+
+=item sqlt_datatype
+
+If present, this is used to infer the actual bind attribute by passing to
+C<< $resolved_storage->bind_attribute_by_data_type() >>. Defaults to the
+"data_type" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>.
+
+Note that the data type is somewhat freeform (hence the sqlt_ prefix);
+currently drivers are expected to "Do the Right Thing" when given a common
+datatype name. (Not ideal, but that's what we got at this point.)
+
+=item sqlt_size
+
+Currently used to correctly allocate buffers for bind_param_inout().
+Defaults to "size" from the L<add_columns column info|DBIx::Class::ResultSource/add_columns>,
+or to a sensible value based on the "data_type".
+
+=item dbic_colname
+
+Used to fill in missing sqlt_datatype and sqlt_size attributes (if they are
+explicitly specified they are never overriden). Also used by some weird DBDs,
+where the column name should be available at bind_param time (e.g. Oracle).
+
+=back
+
+For backwards compatibility and convenience, the following shortcuts are
+supported:
+
+ [ $name => $val ] === [ { dbic_colname => $name }, $val ]
+ [ \$dt => $val ] === [ { sqlt_datatype => $dt }, $val ]
+ [ undef, $val ] === [ {}, $val ]
+ $val === [ {}, $val ]
+
+=head1 AUTHOR AND CONTRIBUTORS
+
+See L<AUTHOR|DBIx::Class/AUTHOR> and L<CONTRIBUTORS|DBIx::Class/CONTRIBUTORS> in DBIx::Class
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
-1;
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