use strict;
use warnings;
use base qw/DBIx::Class/;
-use Carp::Clan qw/^DBIx::Class/;
+use DBIx::Class::Carp;
use DBIx::Class::Exception;
-use Data::Page;
-use Storable;
use DBIx::Class::ResultSetColumn;
-use DBIx::Class::ResultSourceHandle;
-use List::Util ();
use Scalar::Util qw/blessed weaken/;
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
'bool' => "_bool",
fallback => 1;
-__PACKAGE__->mk_group_accessors('simple' => qw/_result_class _source_handle/);
+__PACKAGE__->mk_group_accessors('simple' => qw/_result_class result_source/);
=head1 NAME
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
=head2 Chaining resultsets
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();
}
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 C<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||{}} };
if ($attrs->{page}) {
$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},
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
=item Arguments: $cond, \%attrs?
-=item Return Value: $resultset (scalar context), @row_objs (list context)
+=item Return Value: $resultset (scalar context) || @row_objs (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 row 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>
+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>, 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
}
my $call_attrs = {};
- $call_attrs = pop(@_) if @_ > 1 and ref $_[-1] eq 'HASH';
+ if (@_ > 1) {
+ if (ref $_[-1] eq 'HASH') {
+ # copy for _normalize_selection
+ $call_attrs = { %{ pop @_ } };
+ }
+ elsif (! defined $_[-1] ) {
+ pop @_; # search({}, undef)
+ }
+ }
# see if we can keep the cache (no $rs changes)
my $cache;
$cache = $self->get_cache;
}
+ my $rsrc = $self->result_source;
+
my $old_attrs = { %{$self->{attrs}} };
my $old_having = delete $old_attrs->{having};
my $old_where = delete $old_attrs->{where};
- # reset the selector list
- if (List::Util::first { exists $call_attrs->{$_} } qw{columns select as}) {
- delete @{$old_attrs}{qw{select as columns +select +as +columns include_columns}};
- }
+ my $new_attrs = { %$old_attrs };
+
+ # take care of call attrs (only if anything is changing)
+ if (keys %$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 $new_attrs->{cols}) {
+ if ($new_attrs->{columns}) {
+ carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
+ }
+ else {
+ $new_attrs->{columns} = $c;
+ }
+ }
- my $new_attrs = { %{$old_attrs}, %{$call_attrs} };
- # merge new attrs into inherited
- foreach my $key (qw/join prefetch +select +as +columns include_columns bind/) {
- next unless exists $call_attrs->{$key};
- $new_attrs->{$key} = $self->_merge_attr($old_attrs->{$key}, $call_attrs->{$key});
+ # 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} || [] } ];
}
+
# rip apart the rest of @_, parse a condition
my $call_cond = do {
} if @_;
+ if( @_ > 1 and ! $rsrc->result_class->isa('DBIx::Class::CDBICompat') ) {
+ carp_unique 'search( %condition ) is deprecated, use search( \%condition ) instead';
+ }
+
for ($old_where, $call_cond) {
if (defined $_) {
$new_attrs->{where} = $self->_stack_cond (
)
}
- my $rs = (ref $self)->new($self->result_source, $new_attrs);
+ my $rs = (ref $self)->new($rsrc, $new_attrs);
$rs->set_cache($cache) if ($cache);
return $rs;
}
+my $dark_sel_dumper;
+sub _normalize_selection {
+ my ($self, $attrs) = @_;
+
+ # legacy syntax
+ $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
+ if exists $attrs->{include_columns};
+
+ # columns are always placed first, however
+
+ # Keep the X vs +X separation until _resolved_attrs time - this allows to
+ # delay the decision on whether to use a default select list ($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 { -and => [ map
- { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
- ($left, $right)
- ]};
+ elsif (! defined $left) {
+ return undef;
+ }
+ else {
+ return { -and => [ $left, $right ] };
}
-
- return undef;
}
=head2 search_literal
=item Arguments: $sql_fragment, @bind_values
-=item Return Value: $resultset (scalar context), @row_objs (list context)
+=item Return Value: $resultset (scalar context) || @row_objs (list context)
=back
=over 4
-=item Arguments: @values | \%cols, \%attrs?
+=item Arguments: \%columns_values | @pk_values, \%attrs?
=item Return Value: $row_object | undef
=back
-Finds a row based on its primary key or unique constraint. For example, to find
-a row by its primary key:
+Finds and returns a single row based on supplied criteria. Takes either a
+hashref with the same format as L</create> (including inference of foreign
+keys from related objects), or a list of primary key values in the same
+order as the L<primary columns|DBIx::Class::ResultSource/primary_columns>
+declaration on the L</result_source>.
+
+In either case an attempt is made to combine conditions already existing on
+the resultset with the condition passed to this method.
+
+To aid with preparing the correct query for the storage you may supply the
+C<key> attribute, which is the name of a
+L<unique constraint|DBIx::Class::ResultSource/add_unique_constraint> (the
+unique constraint corresponding to the
+L<primary columns|DBIx::Class::ResultSource/primary_columns> is always named
+C<primary>). If the C<key> attribute has been supplied, and DBIC is unable
+to construct a query that satisfies the named unique constraint fully (
+non-NULL values for each column member of the constraint) an exception is
+thrown.
+
+If no C<key> is specified, the search is carried over all unique constraints
+which are fully defined by the available condition.
+
+If no such constraint is found, C<find> currently defaults to a simple
+C<< search->(\%column_values) >> which may or may not do what you expect.
+Note that this fallback behavior may be deprecated in further versions. If
+you need to search with arbitrary conditions - use L</search>. If the query
+resulting from this fallback produces more than one row, a warning to the
+effect is issued, though only the first row is constructed and returned as
+C<$row_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 $rsrc = $self->result_source;
+ 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")
+ ;
+ }
+
# Parse out the condition from input
my $call_cond;
+
if (ref $_[0] eq 'HASH') {
$call_cond = { %{$_[0]} };
}
else {
- my $constraint = exists $attrs->{key} ? $attrs->{key} : 'primary';
- my @c_cols = $rsrc->unique_constraint_columns($constraint);
+ # 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' constraint?"
+ "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'"
+ . "corresponding to the columns of the specified unique constraint '$constraint_name'"
) unless @c_cols == @_;
$call_cond = {};
next if $keyref eq 'ARRAY'; # has_many for multi_create
my $rel_q = $rsrc->_resolve_condition(
- $relinfo->{cond}, $val, $key
+ $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;
my $alias = exists $attrs->{alias} ? $attrs->{alias} : $self->{attrs}{alias};
my $final_cond;
- if (exists $attrs->{key}) {
+ if (defined $constraint_name) {
$final_cond = $self->_qualify_cond_columns (
$self->_build_unique_cond (
- $attrs->{key},
+ $constraint_name,
$call_cond,
),
}++;
push @unique_queries, try {
- $self->_build_unique_cond ($c_name, $call_cond)
+ $self->_build_unique_cond ($c_name, $call_cond, 'croak_on_nulls')
} || ();
}
$final_cond = @unique_queries
? [ map { $self->_qualify_cond_columns($_, $alias) } @unique_queries ]
- : $self->_qualify_cond_columns($call_cond, $alias)
+ : $self->_non_unique_find_fallback ($call_cond, $attrs)
;
}
}
}
+# This is a stop-gap method as agreed during the discussion on find() cleanup:
+# http://lists.scsys.co.uk/pipermail/dbix-class/2010-October/009535.html
+#
+# It is invoked when find() is called in legacy-mode with insufficiently-unique
+# condition. It is provided for overrides until a saner way forward is devised
+#
+# *NOTE* This is not a public method, and it's *GUARANTEED* to disappear down
+# the road. Please adjust your tests accordingly to catch this situation early
+# DBIx::Class::ResultSet->can('_non_unique_find_fallback') is reasonable
+#
+# The method will not be removed without an adequately complete replacement
+# for strict-mode enforcement
+sub _non_unique_find_fallback {
+ my ($self, $cond, $attrs) = @_;
+
+ return $self->_qualify_cond_columns(
+ $cond,
+ exists $attrs->{alias}
+ ? $attrs->{alias}
+ : $self->{attrs}{alias}
+ );
+}
+
+
sub _qualify_cond_columns {
my ($self, $cond, $alias) = @_;
}
sub _build_unique_cond {
- my ($self, $constraint_name, $extra_cond) = @_;
+ my ($self, $constraint_name, $extra_cond, $croak_on_null) = @_;
my @c_cols = $self->result_source->unique_constraint_columns($constraint_name);
};
# trim out everything not in $columns
- $final_cond = { map { $_ => $final_cond->{$_} } @c_cols };
-
- if (my @missing = grep { ! defined $final_cond->{$_} } (@c_cols) ) {
- $self->throw_exception( sprintf ( "Unable to satisfy constraint '%s', no values for column(s): %s",
+ $final_cond = { map {
+ exists $final_cond->{$_}
+ ? ( $_ => $final_cond->{$_} )
+ : ()
+ } @c_cols };
+
+ 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),
) );
}
+ if (
+ !$croak_on_null
+ and
+ !$ENV{DBIC_NULLABLE_KEY_NOWARN}
+ and
+ my @undefs = 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 $final_cond;
}
=over 4
-=item Arguments: $rel, $cond, \%attrs?
+=item Arguments: $rel, $cond?, \%attrs?
-=item Return Value: $new_resultset
+=item Return Value: $new_resultset (scalar context) || @row_objs (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 row objects instead. To avoid that, use L</search_related_rs>.
+
+See also L</search_related_rs>.
+
=cut
sub search_related {
=item Arguments: $cond, \%attrs?
-=item Return Value: $resultset (scalar context), @row_objs (list context)
+=item Return Value: $resultset (scalar context) || @row_objs (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: $resultset (scalar context) || @row_objs (list context)
=back
# overwrite the selector (supplied by the storage)
$tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
$tmp_attrs->{as} = 'count';
+ delete @{$tmp_attrs}{qw/columns/};
my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
my $sub_attrs = { %$attrs };
# extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
- delete @{$sub_attrs}{qw/collapse select _prefetch_select as order_by for/};
+ delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
- # 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 ( keys %{$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()'
+ );
+ } ]
}
# Calculate subquery selector
if (ref $sel eq 'HASH' and $sel->{-as});
}
- for my $g_part (@$g) {
- my $colpiece = $sel_index->{$g_part} || $g_part;
+ # anything from the original select mentioned on the group-by needs to make it to the inner selector
+ # also look for named aggregates referred in the having clause
+ # having often contains scalarrefs - thus parse it out entirely
+ my @parts = @$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 }
+ $sql_maker->{name_sep} = '';
+ }
+
+ my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
+
+ my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
+
+ # search for both a proper quoted qualified string, for a naive unquoted scalarref
+ # and if all fails for an utterly naive quoted scalar-with-function
+ while ($sql =~ /
+ $rquote $sep $lquote (.+?) $rquote
+ |
+ [\s,] \w+ \. (\w+) [\s,]
+ |
+ [\s,] $lquote (.+?) $rquote [\s,]
+ /gx) {
+ push @parts, ($1 || $2 || $3); # one of them matched if we got here
+ }
+ }
+
+ for (@parts) {
+ my $colpiece = $sel_index->{$_} || $_;
- # disqualify join-based group_by's. Arcane but possible query
+ # unqualify join-based group_by's. Arcane but possible query
# also horrible horrible hack to alias a column (not a func.)
# (probably need to introduce SQLA syntax)
if ($colpiece =~ /\./ && $colpiece !~ /^$attrs->{alias}\./) {
=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 _rs_update_delete {
my ($self, $op, $values) = @_;
+ my $cond = $self->{cond};
my $rsrc = $self->result_source;
+ my $storage = $rsrc->schema->storage;
- # 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});
+ my $attrs = { %{$self->_resolved_attrs} };
- 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/rows offset/);
+ my $existing_group_by = delete $attrs->{group_by};
+ my $needs_subq = defined $existing_group_by;
- if ($needs_group_by_subq or $needs_subq) {
+ # simplify the joinmap and maybe decide if a subquery is necessary
+ my $relation_classifications = {};
- # make a new $rs selecting only the PKs (that's all we really need)
- my $attrs = $self->_resolved_attrs_copy;
+ if (ref($attrs->{from}) eq 'ARRAY') {
+ # if we already know we need a subq, no point of classifying relations
+ if (!$needs_subq and @{$attrs->{from}} > 1) {
+ $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs);
+ $relation_classifications = $storage->_resolve_aliastypes_from_select_args (
+ [ @{$attrs->{from}}[1 .. $#{$attrs->{from}}] ],
+ $attrs->{select},
+ $cond,
+ $attrs
+ );
+ }
+ }
+ else {
+ $needs_subq ||= 1; # if {from} is unparseable assume the worst
+ }
- delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_select as/;
- $attrs->{columns} = [ map { "$attrs->{alias}.$_" } ($self->result_source->_pri_cols) ];
+ # do we need anything like a subquery?
+ if (
+ ! $needs_subq
+ and
+ ! keys %{ $relation_classifications->{restricting} || {} }
+ and
+ ! $self->_has_resolved_attr(qw/rows offset/) # limits call for a 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.
+ my $cond = do {
+ my $sqla = $rsrc->storage->sql_maker;
+ local $sqla->{_dequalify_idents} = 1;
+ \[ $sqla->_recurse_where($self->{cond}) ];
+ };
+ return $rsrc->storage->$op(
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ $cond,
+ );
+ }
+
+ # 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,
+ )
+ );
+
+ # make a new $rs selecting only the PKs (that's all we really need for the subq)
+ delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
+ $attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
+ $attrs->{group_by} = \ ''; # FIXME - this is an evil hack, it causes the optimiser to kick in and throw away the LEFT joins
+ my $subrs = (ref $self)->new($rsrc, $attrs);
- if ($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
+ if (@$idcols == 1) {
+ return $storage->$op (
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ { $idcols->[0] => { -in => $subrs->as_query } },
+ );
+ }
+ elsif ($storage->_use_multicolumn_in) {
+ # This is hideously ugly, but SQLA does not understand multicol IN expressions
+ my $sql_maker = $storage->sql_maker;
+ my ($sql, @bind) = @${$subrs->as_query};
+ $sql = sprintf ('(%s) IN %s', # the as_query already comes with a set of parenthesis
+ join (', ', map { $sql_maker->_quote ($_) } @$idcols),
+ $sql,
+ );
- if (my $g = $attrs->{group_by}) {
+ return $storage->$op (
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ \[$sql, @bind],
+ );
+ }
+ 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 starts to matter
+ if (
+ $existing_group_by
+ or
+ keys %{ $relation_classifications->{multiplying} || {} }
+ ) {
+ # make sure if there is a supplied group_by it matches the columns compiled above
+ # perfectly. Anything else can not be sanely executed on most databases so croak
+ # right then and there
+ if ($existing_group_by) {
my @current_group_by = map
{ $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
- @$g
+ @$existing_group_by
;
if (
);
}
}
- else {
- $attrs->{group_by} = $attrs->{columns};
- }
+
+ $subrs = $subrs->search({}, { group_by => $attrs->{columns} });
}
- my $subrs = (ref $self)->new($rsrc, $attrs);
- return $self->result_source->storage->_subq_update_delete($subrs, $op, $values);
- }
- else {
- return $rsrc->storage->$op(
+ my $guard = $storage->txn_scope_guard;
+
+ my @op_condition;
+ for my $row ($subrs->cursor->all) {
+ push @op_condition, { map
+ { $idcols->[$_] => $row->[$_] }
+ (0 .. $#$idcols)
+ };
+ }
+
+ my $res = $storage->$op (
$rsrc,
$op eq 'update' ? $values : (),
- $cond,
+ \@op_condition,
);
+
+ $guard->commit;
+
+ return $res;
}
}
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>.
+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
sub update {
unless ref $values eq 'HASH';
my $guard = $self->result_source->schema->txn_scope_guard;
- $_->update($values) for $self->all;
+ $_->update({%$values}) for $self->all; # shallow copy - update will mangle it
$guard->commit;
return 1;
}
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>.
+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.
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.
+for submitting to a $resultset->create(...) method.
In void context, C<insert_bulk> in L<DBIx::Class::Storage::DBI> is used
to insert the data, as this is a faster method.
# 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));
}
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]->{$rel};
my @inherit_data = values %$rs_data;
## do bulk insert on current row
- $self->result_source->storage->insert_bulk(
- $self->result_source,
+ $rsrc->storage->insert_bulk(
+ $rsrc,
[@columns, @inherit_cols],
[ map { [ @$_{@columns}, @inherit_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') {
=cut
-# make a wizard good for both a scalar and a hashref
-my $mk_lazy_count_wizard = sub {
- require Variable::Magic;
-
- my $stash = { total_rs => shift };
- my $slot = shift; # only used by the hashref magic
-
- my $magic = Variable::Magic::wizard (
- data => sub { $stash },
-
- (!$slot)
- ? (
- # the scalar magic
- get => sub {
- # set value lazily, and dispell for good
- ${$_[0]} = $_[1]{total_rs}->count;
- Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref});
- return 1;
- },
- set => sub {
- # an explicit set implies dispell as well
- # the unless() is to work around "fun and giggles" below
- Variable::Magic::dispell (${$_[0]}, $_[1]{magic_selfref})
- unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
- return 1;
- },
- )
- : (
- # the uvar magic
- fetch => sub {
- if ($_[2] eq $slot and !$_[1]{inactive}) {
- my $cnt = $_[1]{total_rs}->count;
- $_[0]->{$slot} = $cnt;
-
- # attempting to dispell in a fetch handle (works in store), seems
- # to invariable segfault on 5.10, 5.12, 5.13 :(
- # so use an inactivator instead
- #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
- $_[1]{inactive}++;
- }
- return 1;
- },
- store => sub {
- if (! $_[1]{inactive} and $_[2] eq $slot) {
- #Variable::Magic::dispell (%{$_[0]}, $_[1]{magic_selfref});
- $_[1]{inactive}++
- unless (caller(2))[3] eq 'DBIx::Class::ResultSet::pager';
- }
- return 1;
- },
- ),
- );
-
- $stash->{magic_selfref} = $magic;
- weaken ($stash->{magic_selfref}); # this fails on 5.8.1
-
- return $magic;
-};
-
-# the tie class for 5.8.1
-{
- package DBIx::Class::__DBIC_LAZY_RS_COUNT__;
- use base qw/Tie::Hash/;
-
- sub FIRSTKEY { my $dummy = scalar keys %{$_[0]{data}}; each %{$_[0]{data}} }
- sub NEXTKEY { each %{$_[0]{data}} }
- sub EXISTS { exists $_[0]{data}{$_[1]} }
- sub DELETE { delete $_[0]{data}{$_[1]} }
- sub CLEAR { %{$_[0]{data}} = () }
- sub SCALAR { scalar %{$_[0]{data}} }
-
- sub TIEHASH {
- $_[1]{data} = {%{$_[1]{selfref}}};
- %{$_[1]{selfref}} = ();
- Scalar::Util::weaken ($_[1]{selfref});
- return bless ($_[1], $_[0]);
- };
-
- sub FETCH {
- if ($_[1] eq $_[0]{slot}) {
- my $cnt = $_[0]{data}{$_[1]} = $_[0]{total_rs}->count;
- untie %{$_[0]{selfref}};
- %{$_[0]{selfref}} = %{$_[0]{data}};
- return $cnt;
- }
- else {
- $_[0]{data}{$_[1]};
- }
- }
-
- sub STORE {
- $_[0]{data}{$_[1]} = $_[2];
- if ($_[1] eq $_[0]{slot}) {
- untie %{$_[0]{selfref}};
- %{$_[0]{selfref}} = %{$_[0]{data}};
- }
- $_[2];
- }
-}
-
sub pager {
my ($self) = @_;
return $self->{pager} if $self->{pager};
- if ($self->get_cache) {
- $self->throw_exception ('Pagers on cached resultsets are not supported');
- }
-
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_rs = (ref $self)->new($self->result_source, $count_attrs);
-
-### the following may seem awkward and dirty, but it's a thought-experiment
-### necessary for future development of DBIx::DS. Do *NOT* change this code
-### before talking to ribasushi/mst
+ my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
- my $pager = Data::Page->new(
- 0, #start with an empty set
+ 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},
);
-
- my $data_slot = 'total_entries';
-
- # Since we are interested in a cached value (once it's set - it's set), every
- # technique will detach from the magic-host once the time comes to fire the
- # ->count (or in the segfaulting case of >= 5.10 it will deactivate itself)
-
- if ($] < 5.008003) {
- # 5.8.1 throws 'Modification of a read-only value attempted' when one tries
- # to weakref the magic container :(
- # tested on 5.8.1
- tie (%$pager, 'DBIx::Class::__DBIC_LAZY_RS_COUNT__',
- { slot => $data_slot, total_rs => $total_rs, selfref => $pager }
- );
- }
- elsif ($] < 5.010) {
- # We can use magic on the hash value slot. It's interesting that the magic is
- # attached to the hash-slot, and does *not* stop working once I do the dummy
- # assignments after the cast()
- # tested on 5.8.3 and 5.8.9
- my $magic = $mk_lazy_count_wizard->($total_rs);
- Variable::Magic::cast ( $pager->{$data_slot}, $magic );
-
- # this is for fun and giggles
- $pager->{$data_slot} = -1;
- $pager->{$data_slot} = 0;
-
- # this does not work for scalars, but works with
- # uvar magic below
- #my %vals = %$pager;
- #%$pager = ();
- #%{$pager} = %vals;
- }
- else {
- # And the uvar magic
- # works on 5.10.1, 5.12.1 and 5.13.4 in its current form,
- # however see the wizard maker for more notes
- my $magic = $mk_lazy_count_wizard->($total_rs, $data_slot);
- Variable::Magic::cast ( %$pager, $magic );
-
- # still works
- $pager->{$data_slot} = -1;
- $pager->{$data_slot} = 0;
-
- # this now works
- my %vals = %$pager;
- %$pager = ();
- %{$pager} = %vals;
- }
-
- return $self->{pager} = $pager;
}
=head2 page
sub new_result {
my ($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) = $self->_merge_with_rscond($values);
@$cols_from_relations
? (-cols_from_relations => $cols_from_relations)
: (),
- -source_handle => $self->_source_handle,
-result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
);
while ( my($col, $value) = each %implied ) {
my $vref = ref $value;
- if ($vref eq 'HASH' && keys(%$value) && (keys %$value)[0] eq '=') {
+ if (
+ $vref eq 'HASH'
+ and
+ keys(%$value) == 1
+ and
+ (keys %$value)[0] eq '='
+ ) {
$new_data{$col} = $value->{'='};
}
elsif( !$vref or $vref eq 'SCALAR' or blessed($value) ) {
$cd->cd_to_producer->find_or_new({ producer => $producer },
{ 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
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.
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.
+L</create> process you need to intervene. See also warning pertaining to
+L</new>.
=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 {
=item Arguments: \%col_values, { key => $unique_constraint }?
-=item Return Value: $rowobject
+=item Return Value: $row_object
=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_values) >>.
+
Takes an optional C<key> attribute to search on a specific unique constraint.
For example:
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 {
$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_values) >>.
-Takes an optional C<key> attribute to search on a specific unique constraint.
For example:
# In your application
$cd->insert;
}
+B<Note>: Make sure to read the documentation of L</find> and understand the
+significance of the C<key> attribute, as its lack may skew your search, and
+subsequently result in spurious new objects.
+
B<Note>: Take care when using C<update_or_new> with a table having
columns with default values that you intend to be automatically
supplied by the database (e.g. an auto_increment primary key column).
sub is_ordered {
my ($self) = @_;
- return scalar $self->result_source->storage->_extract_order_columns($self->{attrs}{order_by});
+ return scalar $self->result_source->storage->_extract_order_criteria($self->{attrs}{order_by});
}
=head2 related_resultset
my $me = $self->current_source_alias;
- return $self->search(
+ return $self->search({
"$me.modified" => $user->id,
- );
+ });
}
=cut
return $fresh_rs->search( {}, {
from => [{
$attrs->{alias} => $self->as_query,
- -alias => $attrs->{alias},
- -source_handle => $self->result_source->handle,
+ -alias => $attrs->{alias},
+ -rsrc => $self->result_source,
}],
alias => $attrs->{alias},
});
# 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 group_by distinct select as columns +select +as +columns/};
# 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, qw/where bind/};
}
else {
$from = [{
- -source_handle => $source->handle,
+ -rsrc => $source,
-alias => $attrs->{alias},
$attrs->{alias} => $source->from,
}];
my $source = $self->result_source;
my $alias = $attrs->{alias};
- $attrs->{columns} ||= delete $attrs->{cols} if exists $attrs->{cols};
- my @colbits;
-
- # build columns (as long as select isn't set) into a set of as/select hashes
- unless ( $attrs->{select} ) {
+ # default selection list
+ $attrs->{columns} = [ $source->columns ]
+ unless List::Util::first { exists $attrs->{$_} } qw/columns cols select as/;
- 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 $as (keys %$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} ];
+ # 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;
- 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} }
- ]
- }
- }
- else {
+ 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};
- # otherwise we intialise select & as to empty
- $attrs->{select} = [];
- $attrs->{as} = [];
+ # assume all unqualified selectors to apply to the current alias (legacy stuff)
+ for (@sel) {
+ $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
}
- # 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;
+ # disqualify all $alias.col as-bits (collapser mandated)
+ for (@as) {
+ $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
}
- if ( my $adds = delete $attrs->{'+as'} ) {
- $adds = [$adds] unless ref $adds eq 'ARRAY';
- push @{ $attrs->{as} }, @$adds;
+
+ # 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++;
+ }
}
+ $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 {
- my $storage = $self->result_source->schema->storage;
- my $rs_column_list = $storage->_resolve_column_info ($attrs->{from});
-
- my $group_spec = $attrs->{group_by} = [];
- my %group_index;
-
- for (@{$attrs->{select}}) {
- if (! ref($_) or ref ($_) ne 'HASH' ) {
- push @$group_spec, $_;
- $group_index{$_}++;
- if ($rs_column_list->{$_} and $_ !~ /\./ ) {
- # add a fully qualified version as well
- $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++;
- }
- }
- }
- # 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' } ... ]
- for my $chunk ($storage->_extract_order_columns($attrs->{order_by})) {
-
- # only consider real columns (for functions the user got to do an explicit group_by)
- my $colinfo = $rs_column_list->{$chunk}
- or next;
-
- $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./;
- push @$group_spec, $chunk unless $group_index{$chunk}++;
- }
+ # distinct affects only the main selection part, not what prefetch may
+ # add below.
+ $attrs->{group_by} = $source->storage->_group_over_selection (
+ $attrs->{from},
+ $attrs->{select},
+ $attrs->{order_by},
+ );
}
}
$attrs->{collapse} ||= {};
- if ( my $prefetch = delete $attrs->{prefetch} ) {
- $prefetch = $self->_merge_attr( {}, $prefetch );
+ if ($attrs->{prefetch}) {
+
+ $self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
+ if $attrs->{_dark_selector};
+
+ my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
my $prefetch_ordering = [];
$source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
# we need to somehow mark which columns came from prefetch
- $attrs->{_prefetch_select} = [ map { $_->[0] } @prefetch ];
+ if (@prefetch) {
+ my $sel_end = $#{$attrs->{select}};
+ $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
+ }
- push @{ $attrs->{select} }, @{$attrs->{_prefetch_select}};
+ push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
push( @{$attrs->{order_by}}, @$prefetch_ordering );
}
}
-sub _merge_attr {
+sub _merge_joinpref_attr {
my ($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;
}
-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)
+ delete $to_serialize->{cursor};
+
+ # nor is it sensical to store a not-yet-fired-count pager
+ if ($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(@_);
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
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 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
If you want to fetch related objects from other tables as well, see C<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
Simple prefetches will be joined automatically, so there is no need
for a C<join> attribute in the above search.
-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):
+L</prefetch> can be used with the 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.
+
+ # Assuming:
+ My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
+ My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
+ My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
+ 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('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
+ ]
+ }
+ );
- my $rs = $schema->resultset('Artist')->search(
+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.
+
+However, there is one caveat to be observed: it can be dangerous to
+prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
+relationship on a given level. e.g.:
+
+ my $rs = $schema->resultset('CD')->search(
undef,
{
prefetch => [
- { cds => 'tracks' },
- { artist_tags => 'tags' }
+ 'tracks', # has_many
+ { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
]
}
);
+In fact, C<DBIx::Class> will emit the following warning:
+
+ Prefetching multiple has_many rels tracks and cd_to_producer at top
+ level will explode the number of row objects retrievable via ->next
+ or ->all. Use at your own risk.
+
+The collapser currently can't identify duplicate tuples for multiple
+L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
+result the second L<has_many|DBIx::Class::Relationship/has_many>
+relation could contain redundant objects.
-B<NOTE:> If you specify a C<prefetch> attribute, the C<join> and C<select>
-attributes will be ignored.
+=head3 Using L</prefetch> with L</join>
+
+L</prefetch> implies a L</join> with the equivalent argument, and is
+properly merged with any existing L</join> specification. So the
+following:
+
+ my $rs = $schema->resultset('CD')->search(
+ {'record_label.name' => 'Music Product Ltd.'},
+ {
+ join => {artist => 'record_label'},
+ prefetch => 'artist',
+ }
+ );
-B<CAVEATs>: Prefetch does a lot of deep magic. As such, it may not behave
-exactly as you might expect.
+... will work, searching on the record label's name, but only
+prefetching the C<artist>.
+
+=head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
+
+L</prefetch> implies a L</+select>/L</+as> with the fields of the
+prefetched relations. So given:
+
+ my $rs = $schema->resultset('CD')->search(
+ undef,
+ {
+ select => ['cd.title'],
+ as => ['cd_title'],
+ prefetch => 'artist',
+ }
+ );
+
+The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
+becomes: C<'cd_title', 'artist.*'>.
+
+=head3 CAVEATS
+
+Prefetch does a lot of deep magic. As such, it may not behave exactly
+as you might expect.
=over 4
identical to creating a non-pages resultset and then calling ->page($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
projects / dbsrgits/DBIx-Class.git / blobdiff