X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=49d615fecfccd6cadcaa174a7b03db224cc70e9c;hb=14574c41f268be47c9b54270b9e10421d9ea656e;hp=f2a0b375c9c32147bb98d962a8916cb02bbad4f2;hpb=9229f20afca715e8a1c7e852e46d9333dd392548;p=dbsrgits%2FDBIx-Class-Historic.git diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm index f2a0b37..49d615f 100644 --- a/lib/DBIx/Class/ResultSet.pm +++ b/lib/DBIx/Class/ResultSet.pm @@ -3,116 +3,1783 @@ package DBIx::Class::ResultSet; use strict; use warnings; use overload - '0+' => 'count', + '0+' => \&count, + 'bool' => sub { 1; }, fallback => 1; use Data::Page; +use Storable; +use Scalar::Util qw/weaken/; + +use DBIx::Class::ResultSetColumn; +use base qw/DBIx::Class/; +__PACKAGE__->load_components(qw/AccessorGroup/); +__PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/); + +=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('CD')->search(year => 2005); + +=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 +or a C relationship. + +In the examples below, the following table classes are used: + + package MyApp::Schema::Artist; + use base qw/DBIx::Class/; + __PACKAGE__->load_components(qw/Core/); + __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__->load_components(qw/Core/); + __PACKAGE__->table('cd'); + __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 + +=over 4 + +=item Arguments: $source, \%$attrs + +=item Return Value: $rs + +=back + +The resultset constructor. Takes a source object (usually a +L) and an attribute hash (see +L 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 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 + + my $cd = $schema->resultset('CD')->new({ title => 'Spoon' }); + +will return a CD object, not a ResultSet. + +=cut sub new { - my ($it_class, $db_class, $attrs) = @_; - #use Data::Dumper; warn Dumper(@_); - $it_class = ref $it_class if ref $it_class; - $attrs = { %{ $attrs || {} } }; - my $cols = [ $db_class->_select_columns ]; - my $new = { - class => $db_class, - cols => $cols, + my $class = shift; + return $class->new_result(@_) if ref $class; + + my ($source, $attrs) = @_; + weaken $source; + $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } }; + #use Data::Dumper; warn Dumper($attrs); + my $alias = ($attrs->{alias} ||= 'me'); + + $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols}; + delete $attrs->{as} if $attrs->{columns}; + $attrs->{columns} ||= [ $source->columns ] unless $attrs->{select}; + $attrs->{select} = [ + map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} + ] if $attrs->{columns}; + $attrs->{as} ||= [ + map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} + ]; + if (my $include = delete $attrs->{include_columns}) { + push(@{$attrs->{select}}, @$include); + push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include); + } + #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/}); + + $attrs->{from} ||= [ { $alias => $source->from } ]; + $attrs->{seen_join} ||= {}; + my %seen; + 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}}, $source->resolve_join( + $join, $attrs->{alias}, $attrs->{seen_join}) + ); + } + + $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct}; + $attrs->{order_by} = [ $attrs->{order_by} ] if + $attrs->{order_by} and !ref($attrs->{order_by}); + $attrs->{order_by} ||= []; + + my $collapse = $attrs->{collapse} || {}; + if (my $prefetch = delete $attrs->{prefetch}) { + my @pre_order; + foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) { + if ( ref $p eq 'HASH' ) { + foreach my $key (keys %$p) { + push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) + unless $seen{$key}; + } + } else { + push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) + unless $seen{$p}; + } + my @prefetch = $source->resolve_prefetch( + $p, $attrs->{alias}, {}, \@pre_order, $collapse); + push(@{$attrs->{select}}, map { $_->[0] } @prefetch); + push(@{$attrs->{as}}, map { $_->[1] } @prefetch); + } + push(@{$attrs->{order_by}}, @pre_order); + } + $attrs->{collapse} = $collapse; +# use Data::Dumper; warn Dumper($collapse) if keys %{$collapse}; + + if ($attrs->{page}) { + $attrs->{rows} ||= 10; + $attrs->{offset} ||= 0; + $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1)); + } + + bless { + result_source => $source, + result_class => $attrs->{result_class} || $source->result_class, cond => $attrs->{where}, + from => $attrs->{from}, + collapse => $collapse, count => undef, + page => delete $attrs->{page}, pager => undef, - attrs => $attrs }; - bless ($new, $it_class); - $new->pager if ($attrs->{page}); - return $new; + attrs => $attrs + }, $class; +} + +=head2 search + +=over 4 + +=item Arguments: $cond, \%attrs? + +=item Return Value: $resultset (scalar context), @row_objs (list context) + +=back + + my @cds = $cd_rs->search({ year => 2001 }); # "... WHERE year = 2001" + my $new_rs = $cd_rs->search({ year => 2005 }); + + my $new_rs = $cd_rs->search([ { year => 2005 }, { year => 2004 } ]); + # year = 2005 OR year = 2004 + +If you need to pass in additional attributes but no additional condition, +call it as C. + + # "SELECT name, artistid FROM $artist_table" + my @all_artists = $schema->resultset('Artist')->search(undef, { + columns => [qw/name artistid/], + }); + +=cut + +sub search { + my $self = shift; + my $rs = $self->search_rs( @_ ); + return (wantarray ? $rs->all : $rs); +} + +=head2 search_rs + +=over 4 + +=item Arguments: $cond, \%attrs? + +=item Return Value: $resultset + +=back + +This method does the same exact thing as search() except it will +always return a resultset, even in list context. + +=cut + +sub search_rs { + my $self = shift; + + my $attrs = { %{$self->{attrs}} }; + my $having = delete $attrs->{having}; + $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH'; + + my $where = (@_ + ? ((@_ == 1 || ref $_[0] eq "HASH") + ? shift + : ((@_ % 2) + ? $self->throw_exception( + "Odd number of arguments to search") + : {@_})) + : undef()); + if (defined $where) { + $attrs->{where} = (defined $attrs->{where} + ? { '-and' => + [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } + $where, $attrs->{where} ] } + : $where); + } + + if (defined $having) { + $attrs->{having} = (defined $attrs->{having} + ? { '-and' => + [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } + $having, $attrs->{having} ] } + : $having); + } + + my $rs = (ref $self)->new($self->result_source, $attrs); + + unless (@_) { # no search, effectively just a clone + my $rows = $self->get_cache; + if ($rows) { + $rs->set_cache($rows); + } + } + + return $rs; +} + +=head2 search_literal + +=over 4 + +=item Arguments: $sql_fragment, @bind_values + +=item Return Value: $resultset (scalar context), @row_objs (list context) + +=back + + my @cds = $cd_rs->search_literal('year = ? AND title = ?', qw/2001 Reload/); + my $newrs = $artist_rs->search_literal('name = ?', 'Metallica'); + +Pass a literal chunk of SQL to be added to the conditional part of the +resultset query. + +=cut + +sub search_literal { + my ($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 + +=over 4 + +=item Arguments: @values | \%cols, \%attrs? + +=item Return Value: $row_object + +=back + +Finds a row based on its primary key or unique constraint. For example, to find +a row by its primary key: + + my $cd = $schema->resultset('CD')->find(5); + +You can also find a row by a specific unique constraint using the C +attribute. For example: + + my $cd = $schema->resultset('CD')->find('Massive Attack', 'Mezzanine', { key => 'artist_title' }); + +Additionally, you can specify the columns explicitly by name: + + my $cd = $schema->resultset('CD')->find( + { + artist => 'Massive Attack', + title => 'Mezzanine', + }, + { key => 'artist_title' } + ); + +If no C is specified and you explicitly name columns, it searches on all +unique constraints defined on the source, including the primary key. + +If the C is specified as C, it searches only on the primary key. + +See also L and L. For information on how to +declare unique constraints, see +L. + +=cut + +sub find { + my $self = shift; + my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); + + # Parse out a hash from input + my @cols = exists $attrs->{key} + ? $self->result_source->unique_constraint_columns($attrs->{key}) + : $self->result_source->primary_columns; + + my $hash; + if (ref $_[0] eq 'HASH') { + $hash = { %{$_[0]} }; + } + elsif (@_ == @cols) { + $hash = {}; + @{$hash}{@cols} = @_; + } + elsif (@_) { + # For backwards compatibility + $hash = {@_}; + } + else { + $self->throw_exception( + "Arguments to find must be a hashref or match the number of columns in the " + . (exists $attrs->{key} ? "$attrs->{key} unique constraint" : "primary key") + ); + } + + # Check the hash we just parsed against our source's unique constraints + my @constraint_names = exists $attrs->{key} + ? ($attrs->{key}) + : $self->result_source->unique_constraint_names; + $self->throw_exception( + "Can't find unless a primary key or unique constraint is defined" + ) unless @constraint_names; + + my @unique_queries; + foreach my $name (@constraint_names) { + my @unique_cols = $self->result_source->unique_constraint_columns($name); + my $unique_query = $self->_build_unique_query($hash, \@unique_cols); + + # Add the ResultSet's alias + foreach my $key (grep { ! m/\./ } keys %$unique_query) { + $unique_query->{"$self->{attrs}{alias}.$key"} = delete $unique_query->{$key}; + } + + push @unique_queries, $unique_query if %$unique_query; + } + + # Handle cases where the ResultSet already defines the query + my $query = @unique_queries ? \@unique_queries : undef; + + # Run the query + if (keys %$attrs) { + my $rs = $self->search($query, $attrs); + return keys %{$rs->{collapse}} ? $rs->next : $rs->single; + } + else { + return keys %{$self->{collapse}} + ? $self->search($query)->next + : $self->single($query); + } +} + +# _build_unique_query +# +# Constrain the specified query hash based on the specified column names. + +sub _build_unique_query { + my ($self, $query, $unique_cols) = @_; + + my %unique_query = + map { $_ => $query->{$_} } + grep { exists $query->{$_} } + @$unique_cols; + + return \%unique_query; +} + +=head2 search_related + +=over 4 + +=item Arguments: $cond, \%attrs? + +=item Return Value: $new_resultset + +=back + + $new_rs = $cd_rs->search_related('artist', { + name => 'Emo-R-Us', + }); + +Searches the specified relationship, optionally specifying a condition and +attributes for matching records. See L for more information. + +=cut + +sub search_related { + return shift->related_resultset(shift)->search(@_); } +=head2 cursor + +=over 4 + +=item Arguments: none + +=item Return Value: $cursor + +=back + +Returns a storage-driven cursor to the given resultset. See +L for more information. + +=cut + sub cursor { my ($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 $attrs = { %{$self->{attrs}} }; return $self->{cursor} - ||= $db_class->storage->select($db_class->_table_name, $self->{cols}, + ||= $self->result_source->storage->select($self->{from}, $attrs->{select}, $attrs->{where},$attrs); } +=head2 single + +=over 4 + +=item Arguments: $cond? + +=item Return Value: $row_object? + +=back + + my $cd = $schema->resultset('CD')->single({ year => 2001 }); + +Inflates the first result without creating a cursor if the resultset has +any records in it; if not returns nothing. Used by L as an optimisation. + +Can optionally take an additional condition *only* - this is a fast-code-path +method; if you need to add extra joins or similar call ->search and then +->single without a condition on the $rs returned from that. + +=cut + +sub single { + my ($self, $where) = @_; + my $attrs = { %{$self->{attrs}} }; + if ($where) { + if (defined $attrs->{where}) { + $attrs->{where} = { + '-and' => + [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } + $where, delete $attrs->{where} ] + }; + } else { + $attrs->{where} = $where; + } + } + my @data = $self->result_source->storage->select_single( + $self->{from}, $attrs->{select}, + $attrs->{where},$attrs); + return (@data ? $self->_construct_object(@data) : ()); +} + +=head2 get_column + +=over 4 + +=item Arguments: $cond? + +=item Return Value: $resultsetcolumn + +=back + + my $max_length = $rs->get_column('length')->max; + +Returns a ResultSetColumn instance for $column based on $self + +=cut + +sub get_column { + my ($self, $column) = @_; + + my $new = DBIx::Class::ResultSetColumn->new($self, $column); + return $new; +} + +=head2 search_like + +=over 4 + +=item Arguments: $cond, \%attrs? + +=item Return Value: $resultset (scalar context), @row_objs (list context) + +=back + + # WHERE title LIKE '%blue%' + $cd_rs = $rs->search_like({ title => '%blue%'}); + +Performs a search, but uses C instead of C<=> as the condition. Note +that this is simply a convenience method. You most likely want to use +L with specific operators. + +For more information, see L. + +=cut + +sub search_like { + my $class = shift; + my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); + my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_}; + $query->{$_} = { 'like' => $query->{$_} } for keys %$query; + return $class->search($query, { %$attrs }); +} + +=head2 slice + +=over 4 + +=item Arguments: $first, $last + +=item Return Value: $resultset (scalar context), @row_objs (list context) + +=back + +Returns a resultset or object list representing a subset of elements from the +resultset slice is called on. Indexes are from 0, i.e., to get the first +three records, call: + + my ($one, $two, $three) = $rs->slice(0, 2); + +=cut + sub slice { my ($self, $min, $max) = @_; - my $attrs = { %{ $self->{attrs} || {} } }; - $self->{class}->throw("Can't slice without where") unless $attrs->{where}; - $attrs->{offset} = $min; + my $attrs = {}; # = { %{ $self->{attrs} || {} } }; + $attrs->{offset} = $self->{attrs}{offset} || 0; + $attrs->{offset} += $min; $attrs->{rows} = ($max ? ($max - $min + 1) : 1); - my $slice = $self->new($self->{class}, $attrs); - return (wantarray ? $slice->all : $slice); + return $self->search(undef(), $attrs); + #my $slice = (ref $self)->new($self->result_source, $attrs); + #return (wantarray ? $slice->all : $slice); } +=head2 next + +=over 4 + +=item Arguments: none + +=item Return Value: $result? + +=back + +Returns the next element in the resultset (C is there is none). + +Can be used to efficiently iterate over records in the resultset: + + my $rs = $schema->resultset('CD')->search; + while (my $cd = $rs->next) { + print $cd->title; + } + +Note that you need to store the resultset object, and call C on it. +Calling C<< resultset('Table')->next >> repeatedly will always return the +first record from the resultset. + +=cut + sub next { my ($self) = @_; - my @row = $self->cursor->next; + if (my $cache = $self->get_cache) { + $self->{all_cache_position} ||= 0; + return $cache->[$self->{all_cache_position}++]; + } + if ($self->{attrs}{cache}) { + $self->{all_cache_position} = 1; + return ($self->all)[0]; + } + my @row = (exists $self->{stashed_row} ? + @{delete $self->{stashed_row}} : + $self->cursor->next + ); +# warn Dumper(\@row); use Data::Dumper; return unless (@row); - return $self->{class}->_row_to_object($self->{cols}, \@row); + return $self->_construct_object(@row); +} + +sub _construct_object { + my ($self, @row) = @_; + my @as = @{ $self->{attrs}{as} }; + + my $info = $self->_collapse_result(\@as, \@row); + + my $new = $self->result_class->inflate_result($self->result_source, @$info); + + $new = $self->{attrs}{record_filter}->($new) + if exists $self->{attrs}{record_filter}; + return $new; +} + +sub _collapse_result { + my ($self, $as, $row, $prefix) = @_; + + my %const; + + my @copy = @$row; + foreach my $this_as (@$as) { + my $val = shift @copy; + if (defined $prefix) { + if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) { + my $remain = $1; + $remain =~ /^(?:(.*)\.)?([^.]+)$/; + $const{$1||''}{$2} = $val; + } + } else { + $this_as =~ /^(?:(.*)\.)?([^.]+)$/; + $const{$1||''}{$2} = $val; + } + } + + my $info = [ {}, {} ]; + foreach my $key (keys %const) { + if (length $key) { + my $target = $info; + my @parts = split(/\./, $key); + foreach my $p (@parts) { + $target = $target->[1]->{$p} ||= []; + } + $target->[0] = $const{$key}; + } else { + $info->[0] = $const{$key}; + } + } + + my @collapse; + if (defined $prefix) { + @collapse = map { + m/^\Q${prefix}.\E(.+)$/ ? ($1) : () + } keys %{$self->{collapse}} + } else { + @collapse = keys %{$self->{collapse}}; + }; + + if (@collapse) { + my ($c) = sort { length $a <=> length $b } @collapse; + my $target = $info; + foreach my $p (split(/\./, $c)) { + $target = $target->[1]->{$p} ||= []; + } + my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c); + my @co_key = @{$self->{collapse}{$c_prefix}}; + my %co_check = map { ($_, $target->[0]->{$_}); } @co_key; + my $tree = $self->_collapse_result($as, $row, $c_prefix); + my (@final, @raw); + while ( !(grep { + !defined($tree->[0]->{$_}) || + $co_check{$_} ne $tree->[0]->{$_} + } @co_key) ) { + push(@final, $tree); + last unless (@raw = $self->cursor->next); + $row = $self->{stashed_row} = \@raw; + $tree = $self->_collapse_result($as, $row, $c_prefix); + } + @$target = (@final ? @final : [ {}, {} ]); + # single empty result to indicate an empty prefetched has_many + } + + return $info; } +=head2 result_source + +=over 4 + +=item Arguments: $result_source? + +=item Return Value: $result_source + +=back + +An accessor for the primary ResultSource object from which this ResultSet +is derived. + +=cut + + +=head2 count + +=over 4 + +=item Arguments: $cond, \%attrs?? + +=item Return Value: $count + +=back + +Performs an SQL C with the same query as the resultset was built +with to find the number of elements. If passed arguments, does a search +on the resultset and counts the results of that. + +Note: When using C with C, L emulates C +using C. Some databases (notably SQLite) do +not support C with multiple columns. If you are using such a +database, you should only use columns from the main table in your C +clause. + +=cut + sub count { - my ($self) = @_; - my $db_class = $self->{class}; + my $self = shift; + return $self->search(@_)->count if @_ and defined $_[0]; + return scalar @{ $self->get_cache } if $self->get_cache; + + my $count = $self->_count; + return 0 unless $count; + + $count -= $self->{attrs}{offset} if $self->{attrs}{offset}; + $count = $self->{attrs}{rows} if + $self->{attrs}{rows} and $self->{attrs}{rows} < $count; + return $count; +} + +sub _count { # Separated out so pager can get the full count + my $self = shift; + my $select = { count => '*' }; my $attrs = { %{ $self->{attrs} } }; - unless ($self->{count}) { - # offset and order by are not needed to count - delete $attrs->{$_} for qw/offset order_by/; - - my @cols = 'COUNT(*)'; - $self->{count} = $db_class->storage->select_single($db_class->_table_name, \@cols, - $self->{cond}, $attrs); + if (my $group_by = delete $attrs->{group_by}) { + delete $attrs->{having}; + my @distinct = (ref $group_by ? @$group_by : ($group_by)); + # todo: try CONCAT for multi-column pk + my @pk = $self->result_source->primary_columns; + if (@pk == 1) { + foreach my $column (@distinct) { + if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) { + @distinct = ($column); + last; + } + } + } + + $select = { count => { distinct => \@distinct } }; + #use Data::Dumper; die Dumper $select; } - 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}; + + $attrs->{select} = $select; + $attrs->{as} = [qw/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 ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next; + return $count; } +=head2 count_literal + +=over 4 + +=item Arguments: $sql_fragment, @bind_values + +=item Return Value: $count + +=back + +Counts the results in a literal query. Equivalent to calling L +with the passed arguments, then L. + +=cut + +sub count_literal { shift->search_literal(@_)->count; } + +=head2 all + +=over 4 + +=item Arguments: none + +=item Return Value: @objects + +=back + +Returns all elements in the resultset. Called implicitly if the resultset +is returned in list context. + +=cut + sub all { my ($self) = @_; - return map { $self->{class}->_row_to_object($self->{cols}, $_); } - $self->cursor->all; + return @{ $self->get_cache } if $self->get_cache; + + my @obj; + + if (keys %{$self->{collapse}}) { + # Using $self->cursor->all is really just an optimisation. + # If we're collapsing has_many prefetches it probably makes + # very little difference, and this is cleaner than hacking + # _construct_object to survive the approach + $self->cursor->reset; + my @row = $self->cursor->next; + while (@row) { + push(@obj, $self->_construct_object(@row)); + @row = (exists $self->{stashed_row} + ? @{delete $self->{stashed_row}} + : $self->cursor->next); + } + } else { + @obj = map { $self->_construct_object(@$_) } $self->cursor->all; + } + + $self->set_cache(\@obj) if $self->{attrs}{cache}; + return @obj; } +=head2 reset + +=over 4 + +=item Arguments: none + +=item Return Value: $self + +=back + +Resets the resultset's cursor, so you can iterate through the elements again. + +=cut + sub reset { my ($self) = @_; + $self->{all_cache_position} = 0; $self->cursor->reset; return $self; } -sub first { - return $_[0]->reset->next; -} +=head2 first -sub delete { - my ($self) = @_; +=over 4 + +=item Arguments: none + +=item Return Value: $object? + +=back + +Resets the resultset and returns an object for the first result (if the +resultset returns anything). + +=cut + +sub first { + return $_[0]->reset->next; +} + +# _cond_for_update_delete +# +# update/delete require the condition to be modified to handle +# the differing SQL syntax available. This transforms the $self->{cond} +# appropriately, returning the new condition. + +sub _cond_for_update_delete { + my ($self) = @_; + my $cond = {}; + + if (!ref($self->{cond})) { + # No-op. No condition, we're updating/deleting everything + } + elsif (ref $self->{cond} eq 'ARRAY') { + $cond = [ + map { + my %hash; + foreach my $key (keys %{$_}) { + $key =~ /([^.]+)$/; + $hash{$1} = $_->{$key}; + } + \%hash; + } @{$self->{cond}} + ]; + } + elsif (ref $self->{cond} eq 'HASH') { + if ((keys %{$self->{cond}})[0] eq '-and') { + $cond->{-and} = []; + + my @cond = @{$self->{cond}{-and}}; + for (my $i = 0; $i < @cond - 1; $i++) { + my $entry = $cond[$i]; + + my %hash; + if (ref $entry eq 'HASH') { + foreach my $key (keys %{$entry}) { + $key =~ /([^.]+)$/; + $hash{$1} = $entry->{$key}; + } + } + else { + $entry =~ /([^.]+)$/; + $hash{$entry} = $cond[++$i]; + } + + push @{$cond->{-and}}, \%hash; + } + } + else { + foreach my $key (keys %{$self->{cond}}) { + $key =~ /([^.]+)$/; + $cond->{$1} = $self->{cond}{$key}; + } + } + } + else { + $self->throw_exception( + "Can't update/delete on resultset with condition unless hash or array" + ); + } + + return $cond; +} + + +=head2 update + +=over 4 + +=item Arguments: \%values + +=item Return Value: $storage_rv + +=back + +Sets the specified columns in the resultset to the supplied values in a +single query. Return value will be true if the update succeeded or false +if no records were updated; exact type of success value is storage-dependent. + +=cut + +sub update { + my ($self, $values) = @_; + $self->throw_exception("Values for update must be a hash") + unless ref $values eq 'HASH'; + + my $cond = $self->_cond_for_update_delete; + + return $self->result_source->storage->update( + $self->result_source->from, $values, $cond + ); +} + +=head2 update_all + +=over 4 + +=item Arguments: \%values + +=item Return Value: 1 + +=back + +Fetches all objects and updates them one at a time. Note that C +will run DBIC cascade triggers, while L will not. + +=cut + +sub update_all { + my ($self, $values) = @_; + $self->throw_exception("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 + +=over 4 + +=item Arguments: none + +=item Return Value: 1 + +=back + +Deletes the contents of the resultset from its result source. Note that this +will not run DBIC cascade triggers. See L if you need triggers +to run. + +=cut + +sub delete { + my ($self) = @_; + my $del = {}; + + my $cond = $self->_cond_for_update_delete; + + $self->result_source->storage->delete($self->result_source->from, $cond); + return 1; +} + +=head2 delete_all + +=over 4 + +=item Arguments: none + +=item Return Value: 1 + +=back + +Fetches all objects and deletes them one at a time. Note that C +will run DBIC cascade triggers, while L will not. + +=cut + +sub delete_all { + my ($self) = @_; $_->delete for $self->all; return 1; } -*delete_all = \&delete; # Yeah, yeah, yeah ... +=head2 pager + +=over 4 + +=item Arguments: none + +=item Return Value: $pager + +=back + +Return Value a L object for the current resultset. Only makes +sense for queries with a C attribute. + +=cut sub pager { my ($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}; + $self->throw_exception("Can't create pager for non-paged rs") + unless $self->{page}; + $attrs->{rows} ||= 10; + return $self->{pager} ||= Data::Page->new( + $self->_count, $attrs->{rows}, $self->{page}); } +=head2 page + +=over 4 + +=item Arguments: $page_number + +=item Return Value: $rs + +=back + +Returns a resultset for the $page_number page of the resultset on which page +is called, where each page contains a number of rows equal to the 'rows' +attribute set on the resultset (10 by default). + +=cut + sub page { my ($self, $page) = @_; - my $attrs = $self->{attrs}; + my $attrs = { %{$self->{attrs}} }; $attrs->{page} = $page; - return $self->new($self->{class}, $attrs); + return (ref $self)->new($self->result_source, $attrs); +} + +=head2 new_result + +=over 4 + +=item Arguments: \%vals + +=item Return Value: $object + +=back + +Creates an object in the resultset's result class and returns it. + +=cut + +sub new_result { + my ($self, $values) = @_; + $self->throw_exception( "new_result needs a hash" ) + unless (ref $values eq 'HASH'); + $self->throw_exception( + "Can't abstract implicit construct, condition not a hash" + ) if ($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 ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/); + } + my $obj = $self->result_class->new(\%new); + $obj->result_source($self->result_source) if $obj->can('result_source'); + return $obj; +} + +=head2 find_or_new + +=over 4 + +=item Arguments: \%vals, \%attrs? + +=item Return Value: $object + +=back + +Find an existing record from this resultset. If none exists, instantiate a new +result object and return it. The object will not be saved into your storage +until you call L on it. + +If you want objects to be saved immediately, use L instead. + +=cut + +sub find_or_new { + 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 : $self->new_result($hash); +} + +=head2 create + +=over 4 + +=item Arguments: \%vals + +=item Return Value: $object + +=back + +Inserts a record into the resultset and returns the object representing it. + +Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. + +=cut + +sub create { + my ($self, $attrs) = @_; + $self->throw_exception( "create needs a hashref" ) + unless ref $attrs eq 'HASH'; + return $self->new_result($attrs)->insert; +} + +=head2 find_or_create + +=over 4 + +=item Arguments: \%vals, \%attrs? + +=item Return Value: $object + +=back + + $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 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 and L. For information on how to declare +unique constraints, see L. + +=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 + +=over 4 + +=item Arguments: \%col_values, { key => $unique_constraint }? + +=item Return Value: $object + +=back + + $class->update_or_create({ col => $val, ... }); + +First, searches for an existing row matching one of the unique constraints +(including the primary key) on the source of this resultset. If a row is +found, updates it with the other given column values. Otherwise, creates a new +row. + +Takes an optional C 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 is specified, it searches on all unique constraints defined on the +source, including the primary key. + +If the C is specified as C, it searches only on the primary key. + +See also L and L. For information on how to declare +unique constraints, see L. + +=cut + +sub update_or_create { + my $self = shift; + my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); + my $hash = ref $_[0] eq 'HASH' ? shift : {@_}; + + my $row = $self->find($hash, $attrs); + if (defined $row) { + $row->update($hash); + return $row; + } + + return $self->create($hash); +} + +=head2 get_cache + +=over 4 + +=item Arguments: none + +=item Return Value: \@cache_objects? + +=back + +Gets the contents of the cache for the resultset, if the cache is set. + +=cut + +sub get_cache { + shift->{all_cache}; +} + +=head2 set_cache + +=over 4 + +=item Arguments: \@cache_objects + +=item Return Value: \@cache_objects + +=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 +than re-querying the database even if the cache attr is not set. + +=cut + +sub set_cache { + my ( $self, $data ) = @_; + $self->throw_exception("set_cache requires an arrayref") + if defined($data) && (ref $data ne 'ARRAY'); + $self->{all_cache} = $data; +} + +=head2 clear_cache + +=over 4 + +=item Arguments: none + +=item Return Value: [] + +=back + +Clears the cache for the resultset. + +=cut + +sub clear_cache { + shift->set_cache(undef); } +=head2 related_resultset + +=over 4 + +=item Arguments: $relationship_name + +=item Return Value: $resultset + +=back + +Returns a related resultset for the supplied relationship name. + + $artist_rs = $schema->resultset('CD')->related_resultset('Artist'); + +=cut + +sub related_resultset { + my ( $self, $rel ) = @_; + $self->{related_resultsets} ||= {}; + return $self->{related_resultsets}{$rel} ||= do { + #warn "fetching related resultset for rel '$rel'"; + my $rel_obj = $self->result_source->relationship_info($rel); + $self->throw_exception( + "search_related: result source '" . $self->result_source->name . + "' has no such relationship ${rel}") + unless $rel_obj; #die Dumper $self->{attrs}; + + my $rs = $self->search(undef, { join => $rel }); + my $alias = defined $rs->{attrs}{seen_join}{$rel} + && $rs->{attrs}{seen_join}{$rel} > 1 + ? join('_', $rel, $rs->{attrs}{seen_join}{$rel}) + : $rel; + + $self->result_source->schema->resultset($rel_obj->{class} + )->search( undef, + { %{$rs->{attrs}}, + alias => $alias, + select => undef, + as => undef } + ); + }; +} + +=head2 throw_exception + +See L for details. + +=cut + +sub throw_exception { + my $self=shift; + $self->result_source->schema->throw_exception(@_); +} + +# XXX: FIXME: Attributes docs need clearing up + +=head1 ATTRIBUTES + +The resultset takes various attributes that modify its behavior. Here's an +overview of them: + +=head2 order_by + +=over 4 + +=item Value: ($order_by | \@order_by) + +=back + +Which column(s) to order the results by. This is currently passed +through directly to SQL, so you can give e.g. C for a +descending order on the column `year'. + +=head2 columns + +=over 4 + +=item Value: \@columns + +=back + +Shortcut to request a particular set of columns to be retrieved. Adds +C onto the start of any column without a C<.> in it and sets C as normal. (You may also +use the C attribute, as in earlier versions of DBIC.) + +=head2 include_columns + +=over 4 + +=item Value: \@columns + +=back + +Shortcut to include additional columns in the returned results - for example + + $schema->resultset('CD')->search(undef, { + include_columns => ['artist.name'], + join => ['artist'] + }); + +would return all CDs and include a 'name' column to the information +passed to object inflation + +=head2 select + +=over 4 + +=item Value: \@select_columns + +=back + +Indicates which columns should be selected from the storage. You can use +column names, or in the case of RDBMS back ends, function or stored procedure +names: + + $rs = $schema->resultset('Employee')->search(undef, { + select => [ + 'name', + { count => 'employeeid' }, + { sum => 'salary' } + ] + }); + +When you use function/stored procedure names and do not supply an C +attribute, the column names returned are storage-dependent. E.g. MySQL would +return a column named C in the above example. + +=head2 as + +=over 4 + +=item Value: \@inflation_names + +=back + +Indicates column names for object inflation. This is used in conjunction with +C contains one or more function or stored +procedure names: + + $rs = $schema->resultset('Employee')->search(undef, { + select => [ + 'name', + { count => 'employeeid' } + ], + as => ['name', 'employee_count'], + }); + + my $employee = $rs->first(); # get the first Employee + +If the object against which the search is performed already has an accessor +matching a column name specified in C, the value can be retrieved using +the accessor as normal: + + my $name = $employee->name(); + +If on the other hand an accessor does not exist in the object, you need to +use C instead: + + my $employee_count = $employee->get_column('employee_count'); + +You can create your own accessors if required - see +L for details. + +Please note: This will NOT insert an C into the SQL statement +produced, it is used for internal access only. Thus attempting to use the accessor +in an C clause or similar will fail misrably. + +=head2 join + +=over 4 + +=item Value: ($rel_name | \@rel_names | \%rel_names) + +=back + +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 the same join is supplied twice, it will be aliased to _2 (and +similarly for a third time). For e.g. + + my $rs = $schema->resultset('Artist')->search({ + 'cds.title' => 'Down to Earth', + 'cds_2.title' => 'Popular', + }, { + join => [ qw/cds cds/ ], + }); + +will return a set of all artists that have both a cd with title 'Down +to Earth' and a cd with title 'Popular'. + +If you want to fetch related objects from other tables as well, see C +below. + +=head2 prefetch + +=over 4 + +=item Value: ($rel_name | \@rel_names | \%rel_names) + +=back + +Contains one or more 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 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 has no need to go back to the database when we access the +C or C relationships, which saves us two SQL statements in this +case. + +Simple prefetches will be joined automatically, so there is no need +for a C attribute in the above search. If you're prefetching to +depth (e.g. { cd => { artist => 'label' } or similar), you'll need to +specify the join as well. + +C can be used with the following relationship types: C, +C (or if you're using C, any relationship declared +with an accessor type of 'single' or 'filter'). + +=head2 page + +=over 4 + +=item Value: $page + +=back + +Makes the resultset paged and specifies the page to retrieve. Effectively +identical to creating a non-pages resultset and then calling ->page($page) +on it. + +=head2 rows + +=over 4 + +=item Value: $rows + +=back + +Specifes the maximum number of rows for direct retrieval or the number of +rows per page if the page attribute or method is used. + +=head2 group_by + +=over 4 + +=item Value: \@columns + +=back + +A arrayref of columns to group by. Can include columns of joined tables. + + group_by => [qw/ column1 column2 ... /] + +=head2 having + +=over 4 + +=item Value: $condition + +=back + +HAVING is a select statement attribute that is applied between GROUP BY and +ORDER BY. It is applied to the after the grouping calculations have been +done. + + having => { 'count(employee)' => { '>=', 100 } } + +=head2 distinct + +=over 4 + +=item Value: (0 | 1) + +=back + +Set to 1 to group by all columns. + +=head2 cache + +Set to 1 to cache search results. This prevents extra SQL queries if you +revisit rows in your ResultSet: + + my $resultset = $schema->resultset('Artist')->search( undef, { cache => 1 } ); + + while( my $artist = $resultset->next ) { + ... do stuff ... + } + + $rs->first; # without cache, this would issue a query + +By default, searches are not cached. + +For more examples of using these attributes, see +L. + +=head2 from + +=over 4 + +=item Value: \@from_clause + +=back + +The C attribute gives you manual control over the C clause of SQL +statements generated by L, allowing you to express custom C +clauses. + +NOTE: Use this on your own risk. This allows you to shoot off your foot! + +C will usually do what you need and it is strongly recommended that you +avoid using C unless you cannot achieve the desired result using C. +And we really do mean "cannot", not just tried and failed. Attempting to use +this because you're having problems with C is like trying to use x86 +ASM because you've got a syntax error in your C. Trust us on this. + +Now, if you're still really, really sure you need to use this (and if you're +not 100% sure, ask the mailing list first), here's an explanation of how this +works. + +The syntax is as follows - + + [ + { => }, + [ + { => , -join_type => 'inner|left|right' }, + [], # nested JOIN (optional) + { => , ... (more conditions) }, + ], + # More of the above [ ] may follow for additional joins + ] + + + JOIN + + [JOIN ...] + ON = + + +An easy way to follow the examples below is to remember the following: + + Anything inside "[]" is a JOIN + Anything inside "{}" is a condition for the enclosing JOIN + +The following examples utilize a "person" table in a family tree application. +In order to express parent->child relationships, this table is self-joined: + + # Person->belongs_to('father' => 'Person'); + # Person->belongs_to('mother' => 'Person'); + +C can be used to nest joins. Here we return all children with a father, +then search against all mothers of those children: + + $rs = $schema->resultset('Person')->search( + undef, + { + alias => 'mother', # alias columns in accordance with "from" + from => [ + { mother => 'person' }, + [ + [ + { child => 'person' }, + [ + { father => 'person' }, + { 'father.person_id' => 'child.father_id' } + ] + ], + { 'mother.person_id' => 'child.mother_id' } + ], + ] + }, + ); + + # Equivalent SQL: + # SELECT mother.* FROM person mother + # JOIN ( + # person child + # JOIN person father + # ON ( father.person_id = child.father_id ) + # ) + # ON ( mother.person_id = child.mother_id ) + +The type of any join can be controlled manually. To search against only people +with a father in the person table, we could explicitly use C: + + $rs = $schema->resultset('Person')->search( + undef, + { + alias => 'child', # alias columns in accordance with "from" + from => [ + { child => 'person' }, + [ + { father => 'person', -join_type => 'inner' }, + { 'father.id' => 'child.father_id' } + ], + ] + }, + ); + + # Equivalent SQL: + # SELECT child.* FROM person child + # INNER JOIN person father ON child.father_id = father.id + +=cut + 1;