use warnings;
use base qw/DBIx::Class/;
use DBIx::Class::Carp;
-use DBIx::Class::Exception;
use DBIx::Class::ResultSetColumn;
-use Scalar::Util qw/blessed weaken/;
+use Scalar::Util qw/blessed weaken reftype/;
use Try::Tiny;
use Data::Compare (); # no imports!!! guard against insane architecture
'bool' => "_bool",
fallback => 1;
+# 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 result_source/);
=head1 NAME
=head1 SYNOPSIS
- my $users_rs = $schema->resultset('User');
+ 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 $registered_users_rs = $schema->resultset('User')->search({ registered => 1 });
my @cds_in_2005 = $schema->resultset('CD')->search({ year => 2005 })->all();
=head1 DESCRIPTION
=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</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
=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 = $schema->resultset('CD')->new_result({ title => 'Spoon' });
+
+Please also keep in mind that many internals call L</new_result> directly,
+so overloading this method with the idea of intercepting new result object
+creation B<will not work>. See also warning pertaining to L</create>.
+
+=back
=cut
my ($source, $attrs) = @_;
$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;
=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
# 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>.
+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>.
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
+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:
=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] ) {
- @_ = ();
- }
+ my $rsrc = $self->result_source;
+ my ($call_cond, $call_attrs);
- my $call_attrs = {};
- if (@_ > 1) {
- if (ref $_[-1] eq 'HASH') {
- # copy for _normalize_selection
- $call_attrs = { %{ pop @_ } };
- }
- elsif (! defined $_[-1] ) {
- pop @_; # search({}, undef)
+ # Special-case handling for (undef, undef) or (undef)
+ # Note that (foo => undef) is valid deprecated syntax
+ @_ = () if not scalar grep { defined $_ } @_;
+
+ # 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 '');
}
+
+ $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 $_[0]
+ ! defined $call_cond
or
- ref $_[0] eq 'HASH' && ! keys %{$_[0]}
+ ref $call_cond eq 'HASH' && ! keys %$call_cond
or
- ref $_[0] eq 'ARRAY' && ! @{$_[0]}
+ ref $call_cond eq 'ARRAY' && ! @$call_cond
)) {
$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 $old_attrs->{where};
+ my ($old_having, $old_where) = delete @{$old_attrs}{qw(having where)};
my $new_attrs = { %$old_attrs };
# take care of call attrs (only if anything is changing)
- if (keys %$call_attrs) {
+ if ($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/;
# 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'";
}
}
- # rip apart the rest of @_, parse a condition
- my $call_cond = do {
-
- if (ref $_[0] eq 'HASH') {
- (keys %{$_[0]}) ? $_[0] : undef
- }
- elsif (@_ == 1) {
- $_[0]
- }
- elsif (@_ % 2) {
- $self->throw_exception('Odd number of arguments to search')
- }
- else {
- +{ @_ }
- }
-
- } 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} = $self->_stack_cond (
my ($self, $attrs) = @_;
# legacy syntax
- $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
- if exists $attrs->{include_columns};
+ 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
=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: \%columns_values | @pk_values, \%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
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<$row_object>.
+C<$result_object>.
In addition to C<key>, L</find> recognizes and applies standard
L<resultset attributes|/ATTRIBUTES> in the same way as L</search> does.
and
!$ENV{DBIC_NULLABLE_KEY_NOWARN}
and
- my @undefs = grep { ! defined $final_cond->{$_} } (keys %$final_cond)
+ my @undefs = sort grep { ! defined $final_cond->{$_} } (keys %$final_cond)
) {
carp_unique ( sprintf (
"NULL/undef values supplied for requested unique constraint '%s' (NULL "
=over 4
-=item Arguments: $rel, $cond?, \%attrs?
+=item Arguments: $rel_name, $cond?, L<\%attrs?|/ATTRIBUTES>
-=item Return Value: $new_resultset (scalar context) || @row_objs (list context)
+=item Return Value: L<$resultset|/search> (scalar context) | L<@result_objs|DBIx::Class::Manual::ResultClass> (list context)
=back
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>.
+returning a list of result objects instead. To avoid that, use L</search_related_rs>.
See also L</search_related_rs>.
=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: $row_object | undef
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
=back
$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} };
$self->throw_exception(
- 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
+ 'single() can not be used on resultsets collapsing a has_many. Use find( \%cond ) or next() instead'
) if $attrs->{collapse};
if ($where) {
$attrs->{from}, $attrs->{select},
$attrs->{where}, $attrs
)];
+
return undef unless @$data;
- $self->{stashed_rows} = [ $data ];
- $self->_construct_objects->[0];
+ $self->{_stashed_rows} = [ $data ];
+ $self->_construct_results->[0];
}
=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
=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
=item Arguments: none
-=item Return Value: $result | undef
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
=back
return ($self->all)[0];
}
- return shift(@{$self->{stashed_objects}}) if @{ $self->{stashed_objects}||[] };
+ return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
- $self->{stashed_objects} = $self->_construct_objects
+ $self->{_stashed_results} = $self->_construct_results
or return undef;
- return shift @{$self->{stashed_objects}};
+ return shift @{$self->{_stashed_results}};
}
-# Constructs as many objects as it can in one pass while respecting
+# Constructs as many results as it can in one pass while respecting
# cursor laziness. Several modes of operation:
#
-# * Always builds everything present in @{$self->{stashed_rows}}
+# * Always builds everything present in @{$self->{_stashed_rows}}
# * If called with $fetch_all true - pulls everything off the cursor and
-# builds all objects in one pass
+# 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}}
+# and saves the last extra row (if any) in @{$self->{_stashed_rows}}
# OR
# * Just fetches, and collapses/constructs everything as if $fetch_all
# was requested (there is no other way to collapse except for an
# eager cursor)
# * If no collapse is requested - just get the next row, construct and
# return
-sub _construct_objects {
+sub _construct_results {
my ($self, $fetch_all) = @_;
my $rsrc = $self->result_source;
my $attrs = $self->_resolved_attrs;
- my $cursor = $self->cursor;
+
+ 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;
+ }
# this will be used as both initial raw-row collector AND as a RV of
- # _construct_objects. Not regrowing the array twice matters a lot...
- # a suprising amount actually
- my $rows = (delete $self->{stashed_rows}) || [];
+ # _construct_results. Not regrowing the array twice matters a lot...
+ # a surprising amount actually
+ my $rows = delete $self->{_stashed_rows};
+
+ my $cursor; # we may not need one at all
+
+ my $did_fetch_all = $fetch_all;
+
if ($fetch_all) {
# FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
- $rows = [ @$rows, $cursor->all ];
+ $rows = [ ($rows ? @$rows : ()), $self->cursor->all ];
}
- elsif (!$attrs->{collapse}) {
+ 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;
+ }
+ }
+ }
+
+ if (! $did_fetch_all and ! @{$rows||[]} ) {
# FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
- push @$rows, do { my @r = $cursor->next; @r ? \@r : () }
- unless @$rows;
+ $cursor ||= $self->cursor;
+ if (scalar (my @r = $cursor->next) ) {
+ $rows = [ \@r ];
+ }
}
- else {
- $attrs->{_ordered_for_collapse} ||= (!$attrs->{order_by}) ? undef : do {
- my $st = $rsrc->schema->storage;
- my @ord_cols = map
- { $_->[0] }
- ( $st->_extract_order_criteria($attrs->{order_by}) )
- ;
- my $colinfos = $st->_resolve_column_info($attrs->{from}, \@ord_cols);
+ return undef unless @{$rows||[]};
- for (0 .. $#ord_cols) {
- if (
- ! $colinfos->{$ord_cols[$_]}
- or
- $colinfos->{$ord_cols[$_]}{-result_source} != $rsrc
- ) {
- splice @ord_cols, $_;
- last;
- }
+ # sanity check - people are too clever for their own good
+ if ($attrs->{collapse} and my $aliastypes = $attrs->{_sqlmaker_select_args}[3]{_aliastypes} ) {
+
+ 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}}
}
+ }
- # since all we check here are the start of the order_by belonging to the
- # top level $rsrc, a present identifying set will mean that the resultset
- # is ordered by its leftmost table in a tsable manner
- (@ord_cols and $rsrc->_identifying_column_set({ map
- { $colinfos->{$_}{-colname} => $colinfos->{$_} }
- @ord_cols
- })) ? 1 : 0;
- };
+ for my $i (0 .. $#{$attrs->{as}} ) {
+ my $sel = $attrs->{select}[$i];
- if ($attrs->{_ordered_for_collapse}) {
- push @$rows, do { my @r = $cursor->next; @r ? \@r : () };
- }
- # instead of looping over ->next, use ->all in stealth mode
- # FIXME - encapsulation breach, got to be a better way
- elsif (! $cursor->{done}) {
- push @$rows, $cursor->all;
- $cursor->{done} = 1;
- $fetch_all = 1;
+ if (ref $sel eq 'SCALAR') {
+ $sel = $$sel;
+ }
+ elsif( ref $sel eq 'REF' and ref $$sel eq 'ARRAY' ) {
+ $sel = $$sel->[0];
+ }
+
+ $self->throw_exception(
+ 'Result collapse not possible - selection from a has_many source redirected to the main object'
+ ) if ($multiplied_selectors->{$sel} and $attrs->{as}[$i] !~ /\./);
}
}
- return undef unless @$rows;
+ # hotspot - skip the setter
+ my $res_class = $self->_result_class;
- my $res_class = $self->result_class;
- my $inflator = $res_class->can ('inflate_result')
- or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
+ 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 $infmap = $attrs->{as};
- if (!$attrs->{collapse} and $attrs->{_single_object_inflation}) {
- # construct a much simpler array->hash folder for the one-table cases right here
+ $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|HRI]::inflate_result(), and
+ # 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
- if (@$rows < 60) {
- my @as_idx = 0..$#$infmap;
+ elsif (@$rows < 60) {
for my $r (@$rows) {
- $r = $inflator->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } @as_idx } );
+ $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
}
}
else {
eval sprintf (
- '$_ = $inflator->($res_class, $rsrc, { %s }) for @$rows',
+ '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
);
}
}
else {
- ($self->{_row_parser} ||= eval sprintf 'sub { %s }', $rsrc->_mk_row_parser({
+ my $parser_type =
+ $self->{_result_inflator}{is_hri} ? 'hri'
+ : $self->{_result_inflator}{is_core_row} ? 'classic_pruning'
+ : 'classic_nonpruning'
+ ;
+
+ # $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,
- selection => $attrs->{select},
collapse => $attrs->{collapse},
- }) or die $@)->($rows, $fetch_all ? () : (
- # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
- sub { my @r = $cursor->next or return; \@r }, # how the collapser gets more rows
- ($self->{stashed_rows} = []), # where does it stuff excess
- )); # modify $rows in-place, shrinking/extending as necessary
+ 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} ) {
- $_ = $inflator->($res_class, $rsrc, @$_) for @$rows;
+ $err =
+ 'Collapse aborted due to invalid ResultSource metadata - the following '
+ . 'selections are declared non-nullable but NULLs were retrieved: '
+ ;
+ my @violating_idx;
+ COL: for my $i (@$check_non_null_cols) {
+ ! defined $_->[$i] and push @violating_idx, $i and next COL for @$rows;
+ }
+
+ $self->throw_exception( $err . join (', ', map { "'$infmap->[$_]'" } @violating_idx ) )
+ if @violating_idx;
+
+ $unrolled_non_null_cols_to_check = join (',', @$check_non_null_cols);
+ }
+
+ 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
+}
+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
+ }
+ ;
+
+ $self->{_row_parser}{$parser_type}{cref}->(
+ $rows,
+ $next_cref ? ( $next_cref, $self->{_stashed_rows} = [] ) : (),
+ );
- # CDBI compat stuff
- if ($attrs->{record_filter}) {
- $_ = $attrs->{record_filter}->($_) for @$rows;
+ # 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;
}
=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) {
- unless (ref $result_class) { # don't fire this for an object
- $self->ensure_class_loaded($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);
- # THIS LINE WOULD BE A BUG - this accessor specifically exists to
- # permit the user to set result class on one result set only; it only
- # chains if provided to search()
- #$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
=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 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, $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;
my $sub_attrs = { %$attrs };
# extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
- delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
+ delete @{$sub_attrs}{qw/collapse columns as select order_by for/};
# 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
my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
- my $sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
+ my $having_sql = $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} });
+ my %seen_having;
# search for both a proper quoted qualified string, for a naive unquoted scalarref
# and if all fails for an utterly naive quoted scalar-with-function
- while ($sql =~ /
+ while ($having_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
+ my $part = $1 || $2 || $3; # one of them matched if we got here
+ unless ($seen_having{$part}++) {
+ push @parts, $part;
+ }
}
}
->get_column ('count');
}
-sub _bool {
- return 1;
-}
=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
$self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
}
- delete @{$self}{qw/stashed_rows stashed_objects/};
+ delete @{$self}{qw/_stashed_rows _stashed_results/};
if (my $c = $self->get_cache) {
return @$c;
$self->cursor->reset;
- my $objs = $self->_construct_objects('fetch_all') || [];
+ my $objs = $self->_construct_results('fetch_all') || [];
$self->set_cache($objs) if $self->{attrs}{cache};
sub reset {
my ($self) = @_;
- delete @{$self}{qw/_attrs stashed_rows stashed_objects/};
-
+ delete @{$self}{qw/_stashed_rows _stashed_results/};
$self->{all_cache_position} = 0;
$self->cursor->reset;
return $self;
=item Arguments: none
-=item Return Value: $object | undef
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass> | undef
=back
-Resets the resultset and returns an object for the first result (or C<undef>
-if the resultset is empty).
+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
sub _rs_update_delete {
my ($self, $op, $values) = @_;
- my $cond = $self->{cond};
my $rsrc = $self->result_source;
my $storage = $rsrc->schema->storage;
my $attrs = { %{$self->_resolved_attrs} };
- # "needs" is a strong word here - if the subquery is part of an IN clause - no point of
- # even adding the group_by. It will really be used only when composing a poor-man's
- # multicolumn-IN equivalent OR set
- my $needs_group_by_subq = defined $attrs->{group_by};
-
- # simplify the joinmap and maybe decide if a grouping (and thus subquery) is necessary
- my $relation_classifications;
- if (ref($attrs->{from}) eq 'ARRAY') {
- if (@{$attrs->{from}} == 1) {
- # not a fucking JOIN at all, quit with the dickery
- $relation_classifications = {};
- } else {
- $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
- ) unless $needs_group_by_subq; # we already know we need a group, no point of resolving them
- }
- }
- else {
- $needs_group_by_subq ||= 1; # if {from} is unparseable assume the worst
- }
-
- $needs_group_by_subq ||= exists $relation_classifications->{multiplying};
+ my $join_classifications;
+ my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
- # if no subquery - life is easy-ish
- unless (
- $needs_group_by_subq
+ # do we need a subquery for any reason?
+ my $needs_subq = (
+ defined $existing_group_by
or
- keys %$relation_classifications # if any joins at all - need to wrap a subq
+ # if {from} is unparseable wrap a subq
+ ref($attrs->{from}) ne 'ARRAY'
or
- $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 $sqla = $rsrc->storage->sql_maker;
- local $sqla->{_dequalify_idents} = 1;
- return $rsrc->storage->$op(
- $rsrc,
- $op eq 'update' ? $values : (),
- $self->{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,
- )
+ # limits call for a subq
+ $self->_has_resolved_attr(qw/rows offset/)
);
- my $existing_group_by = delete $attrs->{group_by};
- # make a new $rs selecting only the PKs (that's all we really need for the subq)
- delete @{$attrs}{qw/collapse 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, $attrs);
+ # simplify the joinmap, so we can further decide if a subq is necessary
+ if (!$needs_subq and @{$attrs->{from}} > 1) {
- if (@$idcols == 1) {
- return $storage->$op (
- $rsrc,
- $op eq 'update' ? $values : (),
- { $idcols->[0] => { -in => $subrs->as_query } },
- );
+ ($attrs->{from}, $join_classifications) =
+ $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $self->{cond}, $attrs);
+
+ # any non-pruneable non-local restricting joins imply subq
+ $needs_subq = defined List::Util::first { $_ ne $attrs->{alias} } keys %{ $join_classifications->{restricting} || {} };
}
- elsif ($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,
- );
- return $storage->$op (
- $rsrc,
- $op eq 'update' ? $values : (),
- \[$sql, @bind],
- );
+ # 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]{ $attrs->{from}[0]{-alias} }
+ );
+
+ my ($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 {
- # 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
- my $subq_group_by;
- if ($needs_group_by_subq) {
- $subq_group_by = $attrs->{columns};
-
- # make sure if there is a supplied group_by it matches the columns compiled above
- # perfectly. Anything else can not be sanely executed on most databases so croak
- # right then and there
- if ($existing_group_by) {
- my @current_group_by = map
- { $_ =~ /\./ ? $_ : "$attrs->{alias}.$_" }
- @$existing_group_by
- ;
+ # 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,
+ $rsrc->source_name,
+ )
+ );
- if (
- join ("\x00", sort @current_group_by)
- ne
- join ("\x00", sort @$subq_group_by )
- ) {
- $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.'
- );
+ # 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 ];
+
+ # this will be consumed by the pruner waaaaay down the stack
+ $attrs->{_force_prune_multiplying_joins} = 1;
+
+ 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} });
}
- }
- my $guard = $storage->txn_scope_guard;
+ $guard = $storage->txn_scope_guard;
- my @op_condition;
- for my $row ($subrs->search({}, { group_by => $subq_group_by })->cursor->all) {
- push @op_condition, { map
- { $idcols->[$_] => $row->[$_] }
- (0 .. $#$idcols)
- };
+ $cond = [];
+ for my $row ($subrs->cursor->all) {
+ push @$cond, { map
+ { $idcols->[$_] => $row->[$_] }
+ (0 .. $#$idcols)
+ };
+ }
}
+ }
- my $res = $storage->$op (
- $rsrc,
- $op eq 'update' ? $values : (),
- \@op_condition,
- );
+ my $res = $storage->$op (
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ $cond,
+ );
- $guard->commit;
+ $guard->commit if $guard;
- return $res;
- }
+ 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. Note that this will not run any accessor/set_column/update
-triggers, nor will it update any row object instances derived from this
+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
=item Arguments: none
-=item Return Value: $storage_rv
+=item Return Value: $underlying_storage_rv
=back
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 row object instances
+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
=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
-for submitting 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
-Example: Assuming an Artist Class that has many CDs Classes relating:
+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.
- my $Artist_rs = $schema->resultset("Artist");
+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:
- ## Void Context Example
- $Artist_rs->populate([
+ $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' ],
+ ]);
+
+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.
+
+ $schema->resultset("Artist")->populate([
{ artistid => 4, name => 'Manufactured Crap', cds => [
{ title => 'My First CD', year => 2006 },
{ title => 'Yet More Tweeny-Pop crap', year => 2007 },
},
]);
- ## Array Context Example
- my ($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:
-
- $Arstist_rs->populate([
- [qw/artistid name/],
- [100, 'A Formally Unknown Singer'],
- [101, 'A singer that jumped the shark two albums ago'],
- [102, 'An actually cool singer'],
- ]);
-
-Please note an important effect on your data when choosing between void and
-wantarray context. Since void context goes straight to C<insert_bulk> in
-L<DBIx::Class::Storage::DBI> this will skip any component that is overriding
-C<insert>. So if you are using something like L<DBIx-Class-UUIDColumns> to
-create primary keys for you, you will find that your PKs are empty. In this
-case you will have to use the wantarray context in order to create those
-values.
+If you attempt a void-context multi-create as in the example above (each
+Artist also has the related list of CDs), and B<do not> supply the
+necessary autoinc foreign key information, this method will proxy to the
+less efficient L</create>, and then throw the Result objects away. In this
+case there are obviously no benefits to using this method over L</create>.
=cut
return unless @$data;
if(defined wantarray) {
- my @created;
- foreach my $item (@$data) {
- push(@created, $self->create($item));
- }
+ my @created = map { $self->create($_) } @$data;
return wantarray ? @created : \@created;
}
else {
## inherit the data locked in the conditions of the resultset
my ($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
$rsrc->storage->insert_bulk(
$rsrc,
- [@columns, @inherit_cols],
- [ map { [ @$_{@columns}, @inherit_data ] } @$data ],
+ [@columns, keys %$rs_data],
+ [ map { [ @$_{@columns}, values %$rs_data ] } @$data ],
);
## do the has_many relationships
=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
=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) = $self->_merge_with_rscond($values);
- my %new = (
+ my $new = $self->result_class->new({
%$merged_cond,
- @$cols_from_relations
+ ( @$cols_from_relations
? (-cols_from_relations => $cols_from_relations)
- : (),
+ : ()
+ ),
-result_source => $self->result_source, # DO NOT REMOVE THIS, REQUIRED
- );
+ });
- return $self->result_class->new(\%new);
+ if (
+ reftype($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,
+ ));
+ }
+
+ $new;
}
# _merge_with_rscond
=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 using L</find>. if none exists,
instantiate a new result object and return it. The object will not be saved
=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.
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
year => 2005,
});
- if( $cd->in_storage ) {
+ if( !$cd->in_storage ) {
# do some stuff
$cd->insert;
}
=over 4
-=item Arguments: \%col_values, { key => $unique_constraint }?
+=item Arguments: \%col_data, { key => $unique_constraint, L<%attrs|/ATTRIBUTES> }?
-=item Return Value: $row_object
+=item Return Value: L<$result|DBIx::Class::Manual::ResultClass>
=back
$resultset->update_or_create({ col => $val, ... });
Like L</find_or_create>, but if a row is found it is immediately updated via
-C<< $found_row->update (\%col_values) >>.
+C<< $found_row->update (\%col_data) >>.
Takes an optional C<key> attribute to search on a specific unique constraint.
to call L<DBIx::Class::Row/insert> to save the newly created row to the
database!
- my $cd = $schema->resultset('CD')->update_or_new(
- {
- artist => 'Massive Attack',
- title => 'Mezzanine',
- year => 1998,
- },
- { key => 'cd_artist_title' }
- );
-
- if( $cd->in_storage ) {
- # do some stuff
- $cd->insert;
- }
-
=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, ... });
Like L</find_or_new> but if a row is found it is immediately updated via
-C<< $found_row->update (\%col_values) >>.
+C<< $found_row->update (\%col_data) >>.
For example:
=item Arguments: none
-=item Return Value: \@cache_objects | undef
+=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
=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);
#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;
+ }
+
$new;
};
}
=cut
sub current_source_alias {
- my ($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
# ->_resolve_join as otherwise they get lost - captainL
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/};
+ delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
return {%$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};
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) {
+ for my $as (sort keys %$c) {
push @sel, $c->{$as};
push @as, $as;
}
carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
}
else {
+ $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->{from},
- $attrs->{select},
- $attrs->{order_by},
- );
+ $attrs->{group_by} = $source->storage->_group_over_selection($attrs);
}
}
my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
- # we need to somehow mark which columns came from prefetch
- if (@prefetch) {
- my $sel_end = $#{$attrs->{select}};
- $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
- }
-
push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
}
- $attrs->{_single_object_inflation} = ! List::Util::first { $_ =~ /\./ } @{$attrs->{as}};
+ 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;
}
}
- if (! $attrs->{order_by} and $attrs->{collapse}) {
- # default order for collapsing unless the user asked for something
- $attrs->{order_by} = [ map { "$alias.$_" } $source->primary_columns ];
- $attrs->{_ordered_for_collapse} = 1;
- $attrs->{_order_is_artificial} = 1;
- }
-
# if both page and offset are specified, produce a combined offset
# even though it doesn't make much sense, this is what pre 081xx has
# been doing
$seen_keys->{$import_key} = 1; # don't merge the same key twice
}
- return $orig;
+ return @$orig ? $orig : ();
}
{
# A cursor in progress can't be serialized (and would make little sense anyway)
# the parser can be regenerated (and can't be serialized)
- delete @{$to_serialize}{qw/cursor _row_parser/};
+ 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') {
}
}
+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>.
=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:-
$schema->resultset('CD')->search(undef, {
'+columns' => ['artist.name'],
=back
-=head2 +as
-
-=over 4
-
-Indicates additional column names for those added via L</+select>. See L</as>.
-
-=back
-
=head2 as
=over 4
You can create your own accessors if required - see
L<DBIx::Class::Manual::Cookbook> for details.
+=head2 +as
+
+=over 4
+
+Indicates additional column names for those added via L</+select>. See L</as>.
+
+=back
+
=head2 join
=over 4
will return a set of all artists that have both a cd with title 'Down
to Earth' and a cd with title 'Popular'.
-If you want to fetch related objects from other tables as well, see C<prefetch>
+If you want to fetch related objects from other tables as well, see L</prefetch>
below.
+ NOTE: An internal join-chain pruner will discard certain joins while
+ constructing the actual SQL query, as long as the joins in question do not
+ affect the retrieved result. This for example includes 1:1 left joins
+ that are not part of the restriction specification (WHERE/HAVING) nor are
+ a part of the query selection.
+
For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
-=head2 prefetch
+=head2 collapse
=over 4
-=item Value: ($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'
- }
- }
- );
-
-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.
-
-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' );
+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:
- My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
+ my $rs = $schema->resultset('CD')->search({}, {
+ '+columns' => [ qw/ tracks.title tracks.position / ],
+ join => 'tracks',
+ collapse => 1,
+ });
+While executing the following query:
- 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
- ]
- }
- );
+ SELECT me.*, tracks.title, tracks.position
+ FROM cd me
+ LEFT JOIN track tracks
+ ON tracks.cdid = me.cdid
-This will produce SQL like the following:
+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.
- 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
+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.
-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.
+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>.
-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.:
+Setting this attribute on a resultset that does not join any has_many
+relations is a no-op.
- my $rs = $schema->resultset('CD')->search(
- undef,
- {
- prefetch => [
- 'tracks', # has_many
- { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
- ]
- }
- );
+For a more in-depth discussion, see L</PREFETCHING>.
-In fact, C<DBIx::Class> will emit the following warning:
+=head2 prefetch
- Prefetching multiple has_many rels tracks and cd_to_producer at top
- level will explode the number of row objects retrievable via ->next
- or ->all. Use at your own risk.
+=over 4
-The collapser currently can't identify duplicate tuples for multiple
-L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
-result the second L<has_many|DBIx::Class::Relationship/has_many>
-relation could contain redundant objects.
+=item Value: ($rel_name | \@rel_names | \%rel_names)
-=head3 Using L</prefetch> with L</join>
+=back
-L</prefetch> implies a L</join> with the equivalent argument, and is
-properly merged with any existing L</join> specification. So the
-following:
+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:
- my $rs = $schema->resultset('CD')->search(
- {'record_label.name' => 'Music Product Ltd.'},
- {
- join => {artist => 'record_label'},
- prefetch => 'artist',
- }
- );
+ my $rs = $schema->resultset('Artist')->search({}, {
+ prefetch => { cds => ['genre', 'tracks' ] },
+ });
-... will work, searching on the record label's name, but only
-prefetching the C<artist>.
+and
-=head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
+ 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
+ ),
+ ],
+ });
-L</prefetch> implies a L</+select>/L</+as> with the fields of the
-prefetched relations. So given:
+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 $rs = $schema->resultset('CD')->search(
- undef,
- {
- select => ['cd.title'],
- as => ['cd_title'],
- prefetch => 'artist',
- }
- );
+Which generates the following SQL:
-The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
-becomes: C<'cd_title', 'artist.*'>.
+ 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
-=head3 CAVEATS
+For a more in-depth discussion, see L</PREFETCHING>.
-Prefetch does a lot of deep magic. As such, it may not behave exactly
-as you might expect.
+=head2 alias
=over 4
-=item *
-
-Prefetch uses the L</cache> to populate the prefetched relationships. This
-may or may not be what you want.
-
-=item *
+=item Value: $source_alias
-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',
- });
+=back
- my $count = $artist_rs->first->cds->count;
+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 $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
+ my $q = $rs
+ ->related_resultset('CDs')
+ ->related_resultset('Tracks')
+ ->search({
+ 'track.id' => { -ident => 'none_search.id' },
+ })
+ ->as_query;
- my $prefetch_count = $artist_rs_prefetch->first->cds->count;
+ my $ids = $self->search({
+ -not_exists => $q,
+ }, {
+ alias => 'none_search',
+ group_by => 'none_search.id',
+ })->get_column('id')->as_query;
- cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
-
-that cmp_ok() may or may not pass depending on the datasets involved. This
-behavior may or may not survive the 0.09 transition.
+ $self->search({ id => { -in => $ids } })
-=back
+This attribute is directly tied to L</current_source_alias>.
=head2 page
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.
=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;
projects / dbsrgits/DBIx-Class.git / blobdiff