=head1 OVERLOADING
If a resultset is used in a numeric context it returns the L</count>.
-However, if it is used in a booleand context it is always true. So if
+However, if it is used in a boolean context it is always true. So if
you want to check if a resultset has any results use C<if $rs != 0>.
C<if $rs> will always be true.
$rows = $self->get_cache;
}
+ # reset the selector list
+ if (List::Util::first { exists $attrs->{$_} } qw{columns select as}) {
+ delete @{$our_attrs}{qw{select as columns +select +as +columns include_columns}};
+ }
+
my $new_attrs = { %{$our_attrs}, %{$attrs} };
# merge new attrs into inherited
- foreach my $key (qw/join prefetch +select +as bind/) {
+ foreach my $key (qw/join prefetch +select +as +columns include_columns bind/) {
next unless exists $attrs->{$key};
$new_attrs->{$key} = $self->_merge_attr($our_attrs->{$key}, $attrs->{$key});
}
# in ::Relationship::Base::search_related (the row method), and furthermore
# the relationship is of the 'single' type. This means that the condition
# provided by the relationship (already attached to $self) is sufficient,
- # as there can be only one row in the databse that would satisfy the
+ # as there can be only one row in the database that would satisfy the
# relationship
}
else {
=head2 search_related_rs
This method works exactly the same as search_related, except that
-it guarantees a restultset, even in list context.
+it guarantees a resultset, even in list context.
=cut
=item B<Note>
-As of 0.08100, this method enforces the assumption that the preceeding
+As of 0.08100, this method enforces the assumption that the preceding
query returns only one row. If more than one row is returned, you will receive
a warning:
# extra selectors do not go in the subquery and there is no point of ordering it
delete $sub_attrs->{$_} for qw/collapse select _prefetch_select as order_by/;
- # if we prefetch, we group_by primary keys only 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 %{$attrs->{collapse}} ) {
+ # if we multi-prefetch we group_by primary keys only as this is what we would
+ # get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
+ if ( keys %{$attrs->{collapse}} ) {
$sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } ($rsrc->primary_columns) ]
}
$sub_attrs->{select} = $rsrc->storage->_subq_count_select ($rsrc, $sub_attrs);
# this is so that the query can be simplified e.g.
- # * non-limiting joins can be pruned
# * ordering can be thrown away in things like Top limit
$sub_attrs->{-for_count_only} = 1;
],
},
{ artistid => 5, name => 'Angsty-Whiny Girl', cds => [
- { title => 'My parents sold me to a record company' ,year => 2005 },
+ { title => 'My parents sold me to a record company', year => 2005 },
{ title => 'Why Am I So Ugly?', year => 2006 },
{ title => 'I Got Surgery and am now Popular', year => 2007 }
],
[qw/artistid name/],
[100, 'A Formally Unknown Singer'],
[101, 'A singer that jumped the shark two albums ago'],
- [102, 'An actually cool singer.'],
+ [102, 'An actually cool singer'],
]);
Please note an important effect on your data when choosing between void and
B<keyed on the relationship name>. If the relationship is of type C<multi>
(L<DBIx::Class::Relationship/has_many>) - pass an arrayref of hashrefs.
The process will correctly identify columns holding foreign keys, and will
-transparrently populate them from the keys of the corresponding relation.
+transparently populate them from the keys of the corresponding relation.
This can be applied recursively, and will work correctly for a structure
with an arbitrary depth and width, as long as the relationships actually
exists and the correct column data has been supplied.
return !!$self->{attrs}{page};
}
+=head2 is_ordered
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: true, if the resultset has been ordered with C<order_by>.
+
+=back
+
+=cut
+
+sub is_ordered {
+ my ($self) = @_;
+ return scalar $self->result_source->storage->_parse_order_by($self->{attrs}{order_by});
+}
+
=head2 related_resultset
=over 4
->relname_to_table_alias($rel, $join_count);
# since this is search_related, and we already slid the select window inwards
- # (the select/as attrs were deleted in the beginning), we need to flip all
+ # (the select/as attrs were deleted in the beginning), we need to flip all
# left joins to inner, so we get the expected results
# read the comment on top of the actual function to see what this does
$attrs->{from} = $rsrc->schema->storage->_straight_join_to_node ($attrs->{from}, $alias);
return ($self->{attrs} || {})->{alias} || 'me';
}
+=head2 as_subselect_rs
+
+=over 4
+
+=item Arguments: none
+
+=item Return Value: $resultset
+
+=back
+
+Act as a barrier to SQL symbols. The resultset provided will be made into a
+"virtual view" by including it as a subquery within the from clause. From this
+point on, any joined tables are inaccessible to ->search on the resultset (as if
+it were simply where-filtered without joins). For example:
+
+ my $rs = $schema->resultset('Bar')->search({'x.name' => 'abc'},{ join => 'x' });
+
+ # 'x' now pollutes the query namespace
+
+ # So the following works as expected
+ my $ok_rs = $rs->search({'x.other' => 1});
+
+ # But this doesn't: instead of finding a 'Bar' related to two x rows (abc and
+ # def) we look for one row with contradictory terms and join in another table
+ # (aliased 'x_2') which we never use
+ my $broken_rs = $rs->search({'x.name' => 'def'});
+
+ my $rs2 = $rs->as_subselect_rs;
+
+ # doesn't work - 'x' is no longer accessible in $rs2, having been sealed away
+ my $not_joined_rs = $rs2->search({'x.other' => 1});
+
+ # works as expected: finds a 'table' row related to two x rows (abc and def)
+ my $correctly_joined_rs = $rs2->search({'x.name' => 'def'});
+
+Another example of when one might use this would be to select a subset of
+columns in a group by clause:
+
+ my $rs = $schema->resultset('Bar')->search(undef, {
+ group_by => [qw{ id foo_id baz_id }],
+ })->as_subselect_rs->search(undef, {
+ columns => [qw{ id foo_id }]
+ });
+
+In the above example normally columns would have to be equal to the group by,
+but because we isolated the group by into a subselect the above works.
+
+=cut
+
+sub as_subselect_rs {
+ my $self = shift;
+
+ return $self->result_source->resultset->search( undef, {
+ alias => $self->current_source_alias,
+ from => [{
+ $self->current_source_alias => $self->as_query,
+ -alias => $self->current_source_alias,
+ -source_handle => $self->result_source->handle,
+ }]
+ });
+}
+
# This code is called by search_related, and makes sure there
# is clear separation between the joins before, during, and
# after the relationship. This information is needed later
# we consider the last one thus reverse
for my $j (reverse @requested_joins) {
- if ($rel eq $j->[0]{-join_path}[-1]) {
+ my ($last_j) = keys %{$j->[0]{-join_path}[-1]};
+ if ($rel eq $last_j) {
$j->[0]{-relation_chain_depth}++;
$already_joined++;
last;
}
}
-# alternative way to scan the entire chain - not backwards compatible
-# for my $j (reverse @$from) {
-# next unless ref $j eq 'ARRAY';
-# if ($j->[0]{-join_path} && $j->[0]{-join_path}[-1] eq $rel) {
-# $j->[0]{-relation_chain_depth}++;
-# $already_joined++;
-# last;
-# }
-# }
unless ($already_joined) {
push @$from, $source->_resolve_join(
# build columns (as long as select isn't set) into a set of as/select hashes
unless ( $attrs->{select} ) {
- my @cols = ( ref($attrs->{columns}) eq 'ARRAY' )
- ? @{ delete $attrs->{columns}}
- : (
- ( delete $attrs->{columns} )
- ||
- $source->columns
- )
- ;
+ my @cols;
+ if ( ref $attrs->{columns} eq 'ARRAY' ) {
+ @cols = @{ delete $attrs->{columns}}
+ } elsif ( defined $attrs->{columns} ) {
+ @cols = delete $attrs->{columns}
+ } else {
+ @cols = $source->columns
+ }
- @colbits = map {
- ( ref($_) eq 'HASH' )
- ? $_
- : {
- (
- /^\Q${alias}.\E(.+)$/
- ? "$1"
- : "$_"
- )
- =>
- (
- /\./
- ? "$_"
- : "${alias}.$_"
- )
- }
- } @cols;
+ for (@cols) {
+ if ( ref $_ eq 'HASH' ) {
+ push @colbits, $_
+ } else {
+ my $key = /^\Q${alias}.\E(.+)$/
+ ? "$1"
+ : "$_";
+ my $value = /\./
+ ? "$_"
+ : "${alias}.$_";
+ push @colbits, { $key => $value };
+ }
+ }
}
# add the additional columns on
- foreach ( 'include_columns', '+columns' ) {
- push @colbits, map {
- ( ref($_) eq 'HASH' )
- ? $_
- : { ( split( /\./, $_ ) )[-1] => ( /\./ ? $_ : "${alias}.$_" ) }
- } ( ref($attrs->{$_}) eq 'ARRAY' ) ? @{ delete $attrs->{$_} } : delete $attrs->{$_} if ( $attrs->{$_} );
+ 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 };
+ }
+ }
+ }
}
# start with initial select items
( ref $attrs->{select} eq 'ARRAY' )
? [ @{ $attrs->{select} } ]
: [ $attrs->{select} ];
- $attrs->{as} = (
- $attrs->{as}
- ? (
- ref $attrs->{as} eq 'ARRAY'
- ? [ @{ $attrs->{as} } ]
- : [ $attrs->{as} ]
+
+ if ( $attrs->{as} ) {
+ $attrs->{as} =
+ (
+ ref $attrs->{as} eq 'ARRAY'
+ ? [ @{ $attrs->{as} } ]
+ : [ $attrs->{as} ]
)
- : [ map { m/^\Q${alias}.\E(.+)$/ ? $1 : $_ } @{ $attrs->{select} } ]
- );
+ } else {
+ $attrs->{as} = [ map {
+ m/^\Q${alias}.\E(.+)$/
+ ? $1
+ : $_
+ } @{ $attrs->{select} }
+ ]
+ }
}
else {
}
# now add colbits to select/as
- push( @{ $attrs->{select} }, map { values( %{$_} ) } @colbits );
- push( @{ $attrs->{as} }, map { keys( %{$_} ) } @colbits );
+ push @{ $attrs->{select} }, map values %{$_}, @colbits;
+ push @{ $attrs->{as} }, map keys %{$_}, @colbits;
- my $adds;
- if ( $adds = delete $attrs->{'+select'} ) {
+ if ( my $adds = delete $attrs->{'+select'} ) {
$adds = [$adds] unless ref $adds eq 'ARRAY';
- push(
- @{ $attrs->{select} },
- map { /\./ || ref $_ ? $_ : "${alias}.$_" } @$adds
- );
+ push @{ $attrs->{select} },
+ map { /\./ || ref $_ ? $_ : "$alias.$_" } @$adds;
}
- if ( $adds = delete $attrs->{'+as'} ) {
+ if ( my $adds = delete $attrs->{'+as'} ) {
$adds = [$adds] unless ref $adds eq 'ARRAY';
- push( @{ $attrs->{as} }, @$adds );
+ push @{ $attrs->{as} }, @$adds;
}
- $attrs->{from} ||= [ {
+ $attrs->{from} ||= [{
-source_handle => $source->handle,
-alias => $self->{attrs}{alias},
$self->{attrs}{alias} => $source->from,
- } ];
+ }];
if ( $attrs->{join} || $attrs->{prefetch} ) {
$join,
$alias,
{ %{ $attrs->{seen_join} || {} } },
- ($attrs->{seen_join} && keys %{$attrs->{seen_join}})
+ ( $attrs->{seen_join} && keys %{$attrs->{seen_join}})
? $attrs->{from}[-1][0]{-join_path}
: []
,
my %already_grouped = map { $_ => 1 } (@{$attrs->{group_by}});
my $storage = $self->result_source->schema->storage;
+
my $rs_column_list = $storage->_resolve_column_info ($attrs->{from});
- my @chunks = $storage->sql_maker->_order_by_chunks ($attrs->{order_by});
- for my $chunk (map { ref $_ ? @$_ : $_ } (@chunks) ) {
- $chunk =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
+ for my $chunk ($storage->_parse_order_by($attrs->{order_by})) {
if ($rs_column_list->{$chunk} && not $already_grouped{$chunk}++) {
push @{$attrs->{group_by}}, $chunk;
}
my $prefetch_ordering = [];
- my $join_map = $self->_joinpath_aliases ($attrs->{from}, $attrs->{seen_join});
+ # this is a separate structure (we don't look in {from} directly)
+ # as the resolver needs to shift things off the lists to work
+ # properly (identical-prefetches on different branches)
+ my $join_map = {};
+ if (ref $attrs->{from} eq 'ARRAY') {
+
+ my $start_depth = $attrs->{seen_join}{-relation_chain_depth} || 0;
+
+ for my $j ( @{$attrs->{from}}[1 .. $#{$attrs->{from}} ] ) {
+ next unless $j->[0]{-alias};
+ next unless $j->[0]{-join_path};
+ next if ($j->[0]{-relation_chain_depth} || 0) < $start_depth;
+
+ my @jpath = map { keys %$_ } @{$j->[0]{-join_path}};
+
+ my $p = $join_map;
+ $p = $p->{$_} ||= {} for @jpath[ ($start_depth/2) .. $#jpath]; #only even depths are actual jpath boundaries
+ push @{$p->{-join_aliases} }, $j->[0]{-alias};
+ }
+ }
my @prefetch =
$source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
return $self->{_attrs} = $attrs;
}
-sub _joinpath_aliases {
- my ($self, $fromspec, $seen) = @_;
-
- my $paths = {};
- return $paths unless ref $fromspec eq 'ARRAY';
-
- my $cur_depth = $seen->{-relation_chain_depth} || 0;
-
- if ($cur_depth % 2) {
- $self->throw_exception ("-relation_chain_depth is not even, something went horribly wrong ($cur_depth)");
- }
-
- for my $j (@$fromspec) {
-
- next if ref $j ne 'ARRAY';
- next if ($j->[0]{-relation_chain_depth} || 0) < $cur_depth;
-
- my $jpath = $j->[0]{-join_path};
-
- my $p = $paths;
- $p = $p->{$_} ||= {} for @{$jpath}[$cur_depth/2 .. $#$jpath]; #only even depths are actual jpath boundaries
- push @{$p->{-join_aliases} }, $j->[0]{-alias};
- }
-
- return $paths;
-}
-
sub _rollout_attr {
my ($self, $attr) = @_;
will fail miserably.
To get around this limitation, you can supply literal SQL to your
-C<select> attibute that contains the C<AS alias> text, eg:
+C<select> attribute that contains the C<AS alias> text, e.g.
select => [\'myfield AS alias']
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 associted
+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):
my $rs = $schema->resultset('Artist')->search(
=back
-Specifes the maximum number of rows for direct retrieval or the number of
+Specifies the maximum number of rows for direct retrieval or the number of
rows per page if the page attribute or method is used.
=head2 offset
projects / dbsrgits/DBIx-Class.git / blobdiff