use strict;
use warnings;
+use Carp qw/croak/;
use overload
'0+' => 'count',
+ 'bool' => sub { 1; },
fallback => 1;
use Data::Page;
+use Storable;
+
+=head1 NAME
+
+DBIx::Class::ResultSet - Responsible for fetching and creating resultset.
+
+=head1 SYNOPSIS
+
+ my $rs = $schema->resultset('User')->search(registered => 1);
+ my @rows = $schema->resultset('Foo')->search(bar => 'baz');
+
+=head1 DESCRIPTION
+
+The resultset is also known as an iterator. It is responsible for handling
+queries that may return an arbitrary number of rows, e.g. via L</search>
+or a C<has_many> relationship.
+
+In the examples below, the following table classes are used:
+
+ package MyApp::Schema::Artist;
+ use base qw/DBIx::Class/;
+ __PACKAGE__->table('artist');
+ __PACKAGE__->add_columns(qw/artistid name/);
+ __PACKAGE__->set_primary_key('artistid');
+ __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
+ 1;
+
+ package MyApp::Schema::CD;
+ use base qw/DBIx::Class/;
+ __PACKAGE__->table('artist');
+ __PACKAGE__->add_columns(qw/cdid artist title year/);
+ __PACKAGE__->set_primary_key('cdid');
+ __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
+ 1;
+
+=head1 METHODS
+
+=head2 new($source, \%$attrs)
+
+The resultset constructor. Takes a source object (usually a
+L<DBIx::Class::TableInstance>) and an attribute hash (see L</ATRRIBUTES>
+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:
+
+ my $rs = $schema->resultset('CD')->search({ title => '100th Window' });
+
+=cut
sub new {
- my ($it_class, $db_class, $attrs) = @_;
- #use Data::Dumper; warn Dumper(@_);
- $it_class = ref $it_class if ref $it_class;
- $attrs = { %{ $attrs || {} } };
+ my $class = shift;
+ return $class->new_result(@_) if ref $class;
+ my ($source, $attrs) = @_;
+ #use Data::Dumper; warn Dumper($attrs);
+ $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
my %seen;
- $attrs->{cols} ||= [ map { "me.$_" } $db_class->_select_columns ];
- $attrs->{from} ||= [ { 'me' => $db_class->_table_name } ];
- if ($attrs->{join}) {
- foreach my $j (ref $attrs->{join} eq 'ARRAY'
- ? (@{$attrs->{join}}) : ($attrs->{join})) {
+ my $alias = ($attrs->{alias} ||= 'me');
+ if ($attrs->{cols} || !$attrs->{select}) {
+ delete $attrs->{as} if $attrs->{cols};
+ my @cols = ($attrs->{cols}
+ ? @{delete $attrs->{cols}}
+ : $source->columns);
+ $attrs->{select} = [ map { m/\./ ? $_ : "${alias}.$_" } @cols ];
+ }
+ $attrs->{as} ||= [ map { m/^$alias\.(.*)$/ ? $1 : $_ } @{$attrs->{select}} ];
+ #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/});
+ $attrs->{from} ||= [ { $alias => $source->from } ];
+ if (my $join = delete $attrs->{join}) {
+ foreach my $j (ref $join eq 'ARRAY'
+ ? (@{$join}) : ($join)) {
if (ref $j eq 'HASH') {
$seen{$_} = 1 foreach keys %$j;
} else {
$seen{$j} = 1;
}
}
- push(@{$attrs->{from}}, $db_class->_resolve_join($attrs->{join}, 'me'));
+ push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}));
}
- foreach my $pre (@{$attrs->{prefetch} || []}) {
- push(@{$attrs->{from}}, $db_class->_resolve_join($pre, 'me'))
+ $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct};
+ foreach my $pre (@{delete $attrs->{prefetch} || []}) {
+ push(@{$attrs->{from}}, $source->resolve_join($pre, $attrs->{alias}))
unless $seen{$pre};
- push(@{$attrs->{cols}},
+ my @pre =
map { "$pre.$_" }
- $db_class->_relationships->{$pre}->{class}->_select_columns);
+ $source->related_source($pre)->columns;
+ push(@{$attrs->{select}}, @pre);
+ push(@{$attrs->{as}}, @pre);
+ }
+ if ($attrs->{page}) {
+ $attrs->{rows} ||= 10;
+ $attrs->{offset} ||= 0;
+ $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1));
}
my $new = {
- class => $db_class,
- cols => $attrs->{cols} || [ $db_class->_select_columns ],
+ source => $source,
cond => $attrs->{where},
- from => $attrs->{from} || $db_class->_table_name,
+ from => $attrs->{from},
count => undef,
+ page => delete $attrs->{page},
pager => undef,
attrs => $attrs };
- bless ($new, $it_class);
- $new->pager if ($attrs->{page});
+ bless ($new, $class);
return $new;
}
+=head2 search
+
+ my @obj = $rs->search({ foo => 3 }); # "... WHERE foo = 3"
+ my $new_rs = $rs->search({ foo => 3 });
+
+If you need to pass in additional attributes but no additional condition,
+call it as C<search({}, \%attrs);>.
+
+ # "SELECT foo, bar FROM $class_table"
+ my @all = $class->search({}, { cols => [qw/foo bar/] });
+
+=cut
+
+sub search {
+ my $self = shift;
+
+ #use Data::Dumper;warn Dumper(@_);
+
+ my $attrs = { %{$self->{attrs}} };
+ if (@_ > 1 && ref $_[$#_] eq 'HASH') {
+ $attrs = { %$attrs, %{ pop(@_) } };
+ }
+
+ my $where = (@_ ? ((@_ == 1 || ref $_[0] eq "HASH") ? shift : {@_}) : undef());
+ if (defined $where) {
+ $where = (defined $attrs->{where}
+ ? { '-and' =>
+ [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
+ $where, $attrs->{where} ] }
+ : $where);
+ $attrs->{where} = $where;
+ }
+
+ my $rs = (ref $self)->new($self->{source}, $attrs);
+
+ return (wantarray ? $rs->all : $rs);
+}
+
+=head2 search_literal
+
+ my @obj = $rs->search_literal($literal_where_cond, @bind);
+ my $new_rs = $rs->search_literal($literal_where_cond, @bind);
+
+Pass a literal chunk of SQL to be added to the conditional part of the
+resultset.
+
+=cut
+
+sub search_literal {
+ my ($self, $cond, @vals) = @_;
+ my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {});
+ $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ];
+ return $self->search(\$cond, $attrs);
+}
+
+=head2 find(@colvalues), find(\%cols, \%attrs?)
+
+Finds a row based on its primary key or unique constraint. For example:
+
+ my $cd = $schema->resultset('CD')->find(5);
+
+Also takes an optional C<key> attribute, to search by a specific key or unique
+constraint. For example:
+
+ my $cd = $schema->resultset('CD')->find_or_create(
+ {
+ artist => 'Massive Attack',
+ title => 'Mezzanine',
+ },
+ { key => 'artist_title' }
+ );
+
+See also L</find_or_create> and L</update_or_create>.
+
+=cut
+
+sub find {
+ my ($self, @vals) = @_;
+ my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
+
+ my @cols = $self->{source}->primary_columns;
+ if (exists $attrs->{key}) {
+ my %uniq = $self->{source}->unique_constraints;
+ $self->( "Unknown key " . $attrs->{key} . " on " . $self->name )
+ unless exists $uniq{$attrs->{key}};
+ @cols = @{ $uniq{$attrs->{key}} };
+ }
+ #use Data::Dumper; warn Dumper($attrs, @vals, @cols);
+ $self->{source}->result_class->throw( "Can't find unless a primary key or unique constraint is defined" )
+ unless @cols;
+
+ my $query;
+ if (ref $vals[0] eq 'HASH') {
+ $query = $vals[0];
+ } elsif (@cols == @vals) {
+ $query = {};
+ @{$query}{@cols} = @vals;
+ } else {
+ $query = {@vals};
+ }
+ #warn Dumper($query);
+ # Useless -> disabled
+ #$self->{source}->result_class->throw( "Can't find unless all primary keys are specified" )
+ # unless (keys %$query >= @pk); # If we check 'em we run afoul of uc/lc
+ # column names etc. Not sure what to do yet
+ return $self->search($query)->next;
+}
+
+=head2 search_related
+
+ $rs->search_related('relname', $cond?, $attrs?);
+
+Search the specified relationship. Optionally specify a condition for matching
+records.
+
+=cut
+
+sub search_related {
+ my ($self, $rel, @rest) = @_;
+ my $rel_obj = $self->{source}->relationship_info($rel);
+ $self->{source}->result_class->throw(
+ "No such relationship ${rel} in search_related")
+ unless $rel_obj;
+ my $rs = $self->search(undef, { join => $rel });
+ return $self->{source}->schema->resultset($rel_obj->{class}
+ )->search( undef,
+ { %{$rs->{attrs}},
+ alias => $rel,
+ select => undef(),
+ as => undef() }
+ )->search(@rest);
+}
+
+=head2 cursor
+
+Returns a storage-driven cursor to the given resultset.
+
+=cut
+
sub cursor {
my ($self) = @_;
- my ($db_class, $attrs) = @{$self}{qw/class attrs/};
- if ($attrs->{page}) {
- $attrs->{rows} = $self->pager->entries_per_page;
- $attrs->{offset} = $self->pager->skipped;
- }
+ my ($source, $attrs) = @{$self}{qw/source attrs/};
+ $attrs = { %$attrs };
return $self->{cursor}
- ||= $db_class->storage->select($self->{from}, $self->{cols},
+ ||= $source->storage->select($self->{from}, $attrs->{select},
$attrs->{where},$attrs);
}
+=head2 search_like
+
+Perform a search, but use C<LIKE> instead of equality as the condition. Note
+that this is simply a convenience method; you most likely want to use
+L</search> with specific operators.
+
+For more information, see L<DBIx::Class::Manual::Cookbook>.
+
+=cut
+
+sub search_like {
+ my $class = shift;
+ my $attrs = { };
+ if (@_ > 1 && ref $_[$#_] eq 'HASH') {
+ $attrs = pop(@_);
+ }
+ my $query = ref $_[0] eq "HASH" ? { %{shift()} }: {@_};
+ $query->{$_} = { 'like' => $query->{$_} } for keys %$query;
+ return $class->search($query, { %$attrs });
+}
+
+=head2 slice($first, $last)
+
+Returns a subset of elements from the resultset.
+
+=cut
+
sub slice {
my ($self, $min, $max) = @_;
my $attrs = { %{ $self->{attrs} || {} } };
- $self->{class}->throw("Can't slice without where") unless $attrs->{where};
- $attrs->{offset} = $min;
+ $attrs->{offset} ||= 0;
+ $attrs->{offset} += $min;
$attrs->{rows} = ($max ? ($max - $min + 1) : 1);
- my $slice = $self->new($self->{class}, $attrs);
+ my $slice = (ref $self)->new($self->{source}, $attrs);
return (wantarray ? $slice->all : $slice);
}
+=head2 next
+
+Returns the next element in the resultset (C<undef> is there is none).
+
+Can be used to efficiently iterate over records in the resultset:
+
+ my $rs = $schema->resultset('CD')->search({});
+ while (my $cd = $rs->next) {
+ print $cd->title;
+ }
+
+=cut
+
sub next {
my ($self) = @_;
my @row = $self->cursor->next;
+# warn Dumper(\@row); use Data::Dumper;
return unless (@row);
return $self->_construct_object(@row);
}
sub _construct_object {
my ($self, @row) = @_;
- my @cols = $self->{class}->_select_columns;
- my $new;
- unless ($self->{attrs}{prefetch}) {
- $new = $self->{class}->_row_to_object(\@cols, \@row);
- } else {
- my @main = splice(@row, 0, scalar @cols);
- $new = $self->{class}->_row_to_object(\@cols, \@main);
- PRE: foreach my $pre (@{$self->{attrs}{prefetch}}) {
- my $rel_obj = $self->{class}->_relationships->{$pre};
- my @pre_cols = $rel_obj->{class}->columns;
- my @vals = splice(@row, 0, scalar @pre_cols);
- my $fetched = $rel_obj->{class}->_row_to_object(\@pre_cols, \@vals);
- $self->{class}->throw("No accessor for prefetched $pre")
- unless defined $rel_obj->{attrs}{accessor};
- if ($rel_obj->{attrs}{accessor} eq 'single') {
- foreach my $pri ($rel_obj->{class}->primary_columns) {
- next PRE unless defined $fetched->get_column($pri);
- }
- $new->{_relationship_data}{$pre} = $fetched;
- } elsif ($rel_obj->{attrs}{accessor} eq 'filter') {
- $new->{_inflated_column}{$pre} = $fetched;
- } else {
- $self->{class}->throw("Don't know to to store prefetched $pre");
- }
+ my @cols = @{ $self->{attrs}{as} };
+ #warn "@cols -> @row";
+ my (%me, %pre);
+ foreach my $col (@cols) {
+ if ($col =~ /([^\.]+)\.([^\.]+)/) {
+ $pre{$1}[0]{$2} = shift @row;
+ } else {
+ $me{$col} = shift @row;
}
}
+ my $new = $self->{source}->result_class->inflate_result(
+ $self->{source}, \%me, \%pre);
$new = $self->{attrs}{record_filter}->($new)
if exists $self->{attrs}{record_filter};
return $new;
}
+=head2 count
+
+Performs an SQL C<COUNT> with the same query as the resultset was built
+with to find the number of elements. If passed arguments, does a search
+on the resultset and counts the results of that.
+
+=cut
+
sub count {
- my ($self) = @_;
- my $db_class = $self->{class};
- my $attrs = { %{ $self->{attrs} } };
- unless ($self->{count}) {
- # offset and order by are not needed to count
- delete $attrs->{$_} for qw/offset order_by/;
+ my $self = shift;
+ return $self->search(@_)->count if @_ && defined $_[0];
+ croak "Unable to ->count with a GROUP BY" if defined $self->{attrs}{group_by};
+ unless (defined $self->{count}) {
+ my $attrs = { %{ $self->{attrs} },
+ select => { 'count' => '*' },
+ as => [ 'count' ] };
+ # offset, order by and page are not needed to count. record_filter is cdbi
+ delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/;
- my @cols = 'COUNT(*)';
- $self->{count} = $db_class->storage->select_single($self->{from}, \@cols,
- $self->{cond}, $attrs);
+ ($self->{count}) = (ref $self)->new($self->{source}, $attrs)->cursor->next;
}
return 0 unless $self->{count};
- return $self->{pager}->entries_on_this_page if ($self->{pager});
- return ( $attrs->{rows} && $attrs->{rows} < $self->{count} )
- ? $attrs->{rows}
- : $self->{count};
+ my $count = $self->{count};
+ $count -= $self->{attrs}{offset} if $self->{attrs}{offset};
+ $count = $self->{attrs}{rows} if
+ ($self->{attrs}{rows} && $self->{attrs}{rows} < $count);
+ return $count;
}
+=head2 count_literal
+
+Calls L</search_literal> with the passed arguments, then L</count>.
+
+=cut
+
+sub count_literal { shift->search_literal(@_)->count; }
+
+=head2 all
+
+Returns all elements in the resultset. Called implictly if the resultset
+is returned in list context.
+
+=cut
+
sub all {
my ($self) = @_;
return map { $self->_construct_object(@$_); }
$self->cursor->all;
}
+=head2 reset
+
+Resets the resultset's cursor, so you can iterate through the elements again.
+
+=cut
+
sub reset {
my ($self) = @_;
$self->cursor->reset;
return $self;
}
+=head2 first
+
+Resets the resultset and returns the first element.
+
+=cut
+
sub first {
return $_[0]->reset->next;
}
+=head2 update(\%values)
+
+Sets the specified columns in the resultset to the supplied values.
+
+=cut
+
+sub update {
+ my ($self, $values) = @_;
+ croak "Values for update must be a hash" unless ref $values eq 'HASH';
+ return $self->{source}->storage->update(
+ $self->{source}->from, $values, $self->{cond});
+}
+
+=head2 update_all(\%values)
+
+Fetches all objects and updates them one at a time. Note that C<update_all>
+will run cascade triggers while L</update> will not.
+
+=cut
+
+sub update_all {
+ my ($self, $values) = @_;
+ croak "Values for update must be a hash" unless ref $values eq 'HASH';
+ foreach my $obj ($self->all) {
+ $obj->set_columns($values)->update;
+ }
+ return 1;
+}
+
+=head2 delete
+
+Deletes the contents of the resultset from its result source.
+
+=cut
+
sub delete {
my ($self) = @_;
+ $self->{source}->storage->delete($self->{source}->from, $self->{cond});
+ return 1;
+}
+
+=head2 delete_all
+
+Fetches all objects and deletes them one at a time. Note that C<delete_all>
+will run cascade triggers while L</delete> will not.
+
+=cut
+
+sub delete_all {
+ my ($self) = @_;
$_->delete for $self->all;
return 1;
}
-*delete_all = \&delete; # Yeah, yeah, yeah ...
+=head2 pager
+
+Returns a L<Data::Page> object for the current resultset. Only makes
+sense for queries with a C<page> attribute.
+
+=cut
sub pager {
my ($self) = @_;
my $attrs = $self->{attrs};
- delete $attrs->{offset};
- my $rows_per_page = delete $attrs->{rows} || 10;
- $self->{pager} ||= Data::Page->new(
- $self->count, $rows_per_page, $attrs->{page} || 1);
- $attrs->{rows} = $rows_per_page;
- return $self->{pager};
+ croak "Can't create pager for non-paged rs" unless $self->{page};
+ $attrs->{rows} ||= 10;
+ $self->count;
+ return $self->{pager} ||= Data::Page->new(
+ $self->{count}, $attrs->{rows}, $self->{page});
}
+=head2 page($page_num)
+
+Returns a new resultset for the specified page.
+
+=cut
+
sub page {
my ($self, $page) = @_;
- my $attrs = $self->{attrs};
+ my $attrs = { %{$self->{attrs}} };
$attrs->{page} = $page;
- return $self->new($self->{class}, $attrs);
+ return (ref $self)->new($self->{source}, $attrs);
+}
+
+=head2 new_result(\%vals)
+
+Creates a result in the resultset's result class.
+
+=cut
+
+sub new_result {
+ my ($self, $values) = @_;
+ $self->{source}->result_class->throw( "new_result needs a hash" )
+ unless (ref $values eq 'HASH');
+ $self->{source}->result_class->throw( "Can't abstract implicit construct, condition not a hash" )
+ if ($self->{cond} && !(ref $self->{cond} eq 'HASH'));
+ my %new = %$values;
+ my $alias = $self->{attrs}{alias};
+ foreach my $key (keys %{$self->{cond}||{}}) {
+ $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:$alias\.)?([^\.]+)$/);
+ }
+ my $obj = $self->{source}->result_class->new(\%new);
+ $obj->result_source($self->{source}) if $obj->can('result_source');
+ $obj;
+}
+
+=head2 create(\%vals)
+
+Inserts a record into the resultset and returns the object.
+
+Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
+
+=cut
+
+sub create {
+ my ($self, $attrs) = @_;
+ $self->{source}->result_class->throw( "create needs a hashref" ) unless ref $attrs eq 'HASH';
+ return $self->new_result($attrs)->insert;
+}
+
+=head2 find_or_create(\%vals, \%attrs?)
+
+ $class->find_or_create({ key => $val, ... });
+
+Searches for a record matching the search condition; if it doesn't find one,
+creates one and returns that instead.
+
+ my $cd = $schema->resultset('CD')->find_or_create({
+ cdid => 5,
+ artist => 'Massive Attack',
+ title => 'Mezzanine',
+ year => 2005,
+ });
+
+Also takes an optional C<key> attribute, to search by a specific key or unique
+constraint. For example:
+
+ my $cd = $schema->resultset('CD')->find_or_create(
+ {
+ artist => 'Massive Attack',
+ title => 'Mezzanine',
+ },
+ { key => 'artist_title' }
+ );
+
+See also L</find> and L</update_or_create>.
+
+=cut
+
+sub find_or_create {
+ my $self = shift;
+ my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
+ my $hash = ref $_[0] eq "HASH" ? shift : {@_};
+ my $exists = $self->find($hash, $attrs);
+ return defined($exists) ? $exists : $self->create($hash);
+}
+
+=head2 update_or_create
+
+ $class->update_or_create({ key => $val, ... });
+
+First, search for an existing row matching one of the unique constraints
+(including the primary key) on the source of this resultset. If a row is
+found, update it with the other given column values. Otherwise, create a new
+row.
+
+Takes an optional C<key> attribute to search on a specific unique constraint.
+For example:
+
+ # In your application
+ my $cd = $schema->resultset('CD')->update_or_create(
+ {
+ artist => 'Massive Attack',
+ title => 'Mezzanine',
+ year => 1998,
+ },
+ { key => 'artist_title' }
+ );
+
+If no C<key> is specified, it searches on all unique constraints defined on the
+source, including the primary key.
+
+If the C<key> is specified as C<primary>, search only on the primary key.
+
+See also L</find> and L</find_or_create>.
+
+=cut
+
+sub update_or_create {
+ my $self = shift;
+
+ my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
+ my $hash = ref $_[0] eq "HASH" ? shift : {@_};
+
+ my %unique_constraints = $self->{source}->unique_constraints;
+ my @constraint_names = (exists $attrs->{key}
+ ? ($attrs->{key})
+ : keys %unique_constraints);
+
+ my @unique_hashes;
+ foreach my $name (@constraint_names) {
+ my @unique_cols = @{ $unique_constraints{$name} };
+ my %unique_hash =
+ map { $_ => $hash->{$_} }
+ grep { exists $hash->{$_} }
+ @unique_cols;
+
+ push @unique_hashes, \%unique_hash
+ if (scalar keys %unique_hash == scalar @unique_cols);
+ }
+
+ my $row;
+ if (@unique_hashes) {
+ $row = $self->search(\@unique_hashes, { rows => 1 })->first;
+ if ($row) {
+ $row->set_columns($hash);
+ $row->update;
+ }
+ }
+
+ unless ($row) {
+ $row = $self->create($hash);
+ }
+
+ return $row;
}
+=head1 ATTRIBUTES
+
+The resultset takes various attributes that modify its behavior. Here's an
+overview of them:
+
+=head2 order_by
+
+Which column(s) to order the results by. This is currently passed through
+directly to SQL, so you can give e.g. C<foo DESC> for a descending order.
+
+=head2 cols (arrayref)
+
+Shortcut to request a particular set of columns to be retrieved. 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.
+
+=head2 select (arrayref)
+
+Indicates which columns should be selected from the storage.
+
+=head2 as (arrayref)
+
+Indicates column names for object inflation.
+
+=head2 join
+
+Contains a list of relationships that should be joined for this query. For
+example:
+
+ # Get CDs by Nine Inch Nails
+ my $rs = $schema->resultset('CD')->search(
+ { 'artist.name' => 'Nine Inch Nails' },
+ { join => 'artist' }
+ );
+
+Can also contain a hash reference to refer to the other relation's relations.
+For example:
+
+ package MyApp::Schema::Track;
+ use base qw/DBIx::Class/;
+ __PACKAGE__->table('track');
+ __PACKAGE__->add_columns(qw/trackid cd position title/);
+ __PACKAGE__->set_primary_key('trackid');
+ __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD');
+ 1;
+
+ # In your application
+ my $rs = $schema->resultset('Artist')->search(
+ { 'track.title' => 'Teardrop' },
+ {
+ join => { cd => 'track' },
+ order_by => 'artist.name',
+ }
+ );
+
+If you want to fetch the columns from the related table as well, see
+C<prefetch> below.
+
+=head2 prefetch
+
+Contains a list of relationships that should be fetched along with the main
+query (when they are accessed afterwards they will have already been
+"prefetched"). This is useful for when you know you will need the related
+objects, because it saves a query. Currently limited to prefetching
+one relationship deep, so unlike C<join>, prefetch must be an arrayref.
+
+=head2 from
+
+This attribute can contain a arrayref of elements. Each element can be another
+arrayref, to nest joins, or it can be a hash which represents the two sides
+of the join.
+
+NOTE: Use this on your own risk. This allows you to shoot off your foot!
+
+=head2 page
+
+For a paged resultset, specifies which page to retrieve. Leave unset
+for an unpaged resultset.
+
+=head2 rows
+
+For a paged resultset, how many rows per page. Can also be used to simulate an
+SQL C<LIMIT>.
+
+=head2 group_by (arrayref)
+
+A arrayref of columns to group by (note that L</count> doesn't work on grouped
+resultsets).
+
+ group_by => [qw/ column1 column2 ... /]
+
+=head2 distinct
+
+Set to 1 to group by all columns.
+
+For more examples of using these attributes, see
+L<DBIx::Class::Manual::Cookbook>.
+
+=cut
+
1;
projects / dbsrgits/DBIx-Class.git / blobdiff