use strict;
use warnings;
+use Carp qw/croak/;
use overload
'0+' => 'count',
+ 'bool' => sub { 1; },
fallback => 1;
use Data::Page;
use Storable;
=head1 SYNOPSIS
-my $rs = MyApp::DB::Class->search(registered => 1);
-my @rows = MyApp::DB::Class->search(foo => 'bar');
+ my $rs = $schema->resultset('User')->search(registered => 1);
+ my @rows = $schema->resultset('Foo')->search(bar => 'baz');
=head1 DESCRIPTION
The resultset is also known as an iterator. It is responsible for handling
-queries that may return an arbitrary number of rows, e.g. via C<search>
+queries that may return an arbitrary number of rows, e.g. via L</search>
or a C<has_many> relationship.
+In the examples below, the following table classes are used:
+
+ package MyApp::Schema::Artist;
+ use base qw/DBIx::Class/;
+ __PACKAGE__->table('artist');
+ __PACKAGE__->add_columns(qw/artistid name/);
+ __PACKAGE__->set_primary_key('artistid');
+ __PACKAGE__->has_many(cds => 'MyApp::Schema::CD');
+ 1;
+
+ package MyApp::Schema::CD;
+ use base qw/DBIx::Class/;
+ __PACKAGE__->table('artist');
+ __PACKAGE__->add_columns(qw/cdid artist title year/);
+ __PACKAGE__->set_primary_key('cdid');
+ __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist');
+ 1;
+
=head1 METHODS
=head2 new($source, \%$attrs)
-The resultset constructor. Takes a source object (usually a DBIx::Class::Table)
-and an attribute hash (see below for more information on attributes). Does
-not perform any queries -- these are executed as needed by the other methods.
+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 $class = shift;
- $class->new_result(@_) if ref $class;
+ return $class->new_result(@_) if ref $class;
my ($source, $attrs) = @_;
- #use Data::Dumper; warn Dumper(@_);
+ #use Data::Dumper; warn Dumper($attrs);
$attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } };
my %seen;
my $alias = ($attrs->{alias} ||= 'me');
- if (!$attrs->{select}) {
+ if ($attrs->{cols} || !$attrs->{select}) {
+ delete $attrs->{as} if $attrs->{cols};
my @cols = ($attrs->{cols}
? @{delete $attrs->{cols}}
- : $source->result_class->_select_columns);
+ : $source->columns);
$attrs->{select} = [ map { m/\./ ? $_ : "${alias}.$_" } @cols ];
}
$attrs->{as} ||= [ map { m/^$alias\.(.*)$/ ? $1 : $_ } @{$attrs->{select}} ];
unless $seen{$pre};
my @pre =
map { "$pre.$_" }
- $source->result_class->relationship_info($pre)->{class}->columns;
+ $source->related_source($pre)->columns;
push(@{$attrs->{select}}, @pre);
push(@{$attrs->{as}}, @pre);
}
=head2 search
- my @obj = $rs->search({ foo => 3 }); # "... WHERE foo = 3"
- my $new_rs = $rs->search({ foo => 3 });
-
+ 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 ->search(undef, \%attrs);
-
- my @all = $class->search({}, { cols => [qw/foo bar/] }); # "SELECT foo, bar FROM $class_table"
+call it as C<search({}, \%attrs);>.
+
+ # "SELECT foo, bar FROM $class_table"
+ my @all = $class->search({}, { cols => [qw/foo bar/] });
=cut
my $where = (@_ ? ((@_ == 1 || ref $_[0] eq "HASH") ? shift : {@_}) : undef());
if (defined $where) {
$where = (defined $attrs->{where}
- ? { '-and' => [ $where, $attrs->{where} ] }
+ ? { '-and' =>
+ [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ }
+ $where, $attrs->{where} ] }
: $where);
$attrs->{where} = $where;
}
return (wantarray ? $rs->all : $rs);
}
-=head2 search_literal
+=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
+resultset.
=cut
return $self->search(\$cond, $attrs);
}
-=head2 find(@colvalues), find(\%cols)
+=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:
-Finds a row based on its primary key(s).
+ my $cd = $schema->resultset('CD')->find_or_create(
+ {
+ artist => 'Massive Attack',
+ title => 'Mezzanine',
+ },
+ { key => 'artist_title' }
+ );
-=cut
+See also L</find_or_create> and L</update_or_create>.
+
+=cut
sub find {
my ($self, @vals) = @_;
my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
- my @pk = $self->{source}->primary_columns;
- #use Data::Dumper; warn Dumper($attrs, @vals, @pk);
- $self->{source}->result_class->throw( "Can't find unless primary columns are defined" )
- unless @pk;
+
+ 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 (@pk == @vals) {
+ } elsif (@cols == @vals) {
$query = {};
- @{$query}{@pk} = @vals;
+ @{$query}{@cols} = @vals;
} else {
$query = {@vals};
}
$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 = $self->{source}->result_class->relationship_info($rel);
+ my $rel_obj = $self->{source}->relationship_info($rel);
$self->{source}->result_class->throw(
"No such relationship ${rel} in search_related")
unless $rel_obj;
$attrs->{where},$attrs);
}
-=head2 search_like
-
-Identical to search except defaults to 'LIKE' instead of '=' in condition
-
-=cut
+=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;
return (wantarray ? $slice->all : $slice);
}
-=head2 next
+=head2 next
-Returns the next element in the resultset (undef is there is none).
+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);
}
$me{$col} = shift @row;
}
}
- my $new = $self->{source}->result_class->inflate_result(\%me, \%pre);
+ 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;
sub count {
my $self = shift;
return $self->search(@_)->count if @_ && defined $_[0];
- die "Unable to ->count with a GROUP BY" if defined $self->{attrs}{group_by};
+ croak "Unable to ->count with a GROUP BY" if defined $self->{attrs}{group_by};
unless (defined $self->{count}) {
my $attrs = { %{ $self->{attrs} },
select => { 'count' => '*' },
=head2 count_literal
-Calls search_literal with the passed arguments, then count.
+Calls L</search_literal> with the passed arguments, then L</count>.
=cut
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 all elements in the resultset.
+Deletes the contents of the resultset from its result source.
=cut
sub delete {
my ($self) = @_;
- $_->delete for $self->all;
+ $self->{source}->storage->delete($self->{source}->from, $self->{cond});
return 1;
}
-*delete_all = \&delete; # Yeah, yeah, yeah ...
+=head2 delete_all
+
+Fetches all objects and deletes them one at a time. Note that C<delete_all>
+will run cascade triggers while L</delete> will not.
+
+=cut
+
+sub delete_all {
+ my ($self) = @_;
+ $_->delete for $self->all;
+ return 1;
+}
=head2 pager
Returns a L<Data::Page> object for the current resultset. Only makes
-sense for queries with page turned on.
+sense for queries with a C<page> attribute.
=cut
sub pager {
my ($self) = @_;
my $attrs = $self->{attrs};
- die "Can't create pager for non-paged rs" unless $self->{page};
+ croak "Can't create pager for non-paged rs" unless $self->{page};
$attrs->{rows} ||= 10;
$self->count;
return $self->{pager} ||= Data::Page->new(
=head2 new_result(\%vals)
-Creates a result in the resultset's result class
+Creates a result in the resultset's result class.
=cut
foreach my $key (keys %{$self->{cond}||{}}) {
$new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:$alias\.)?([^\.]+)$/);
}
- return $self->{source}->result_class->new(\%new);
+ 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
+Inserts a record into the resultset and returns the object.
-Effectively a shortcut for ->new_result(\%vals)->insert
+Effectively a shortcut for C<< ->new_result(\%vals)->insert >>.
=cut
return $self->new_result($attrs)->insert;
}
-=head2 find_or_create(\%vals)
+=head2 find_or_create(\%vals, \%attrs?)
+
+ $class->find_or_create({ key => $val, ... });
- $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 $hash = ref $_[0] eq "HASH" ? shift: {@_};
- my $exists = $self->find($hash);
+ 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:
+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.
+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
-'me.' onto the start of any column without a '.' in it and sets 'select'
-from that, then auto-populates 'as' from 'select' as normal
+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
+Indicates which columns should be selected from the storage.
=head2 as (arrayref)
-Indicates column names for object inflation
+Indicates column names for object inflation.
=head2 join
-Contains a list of relationships that should be joined for this query. Can also
-contain a hash reference to refer to that relation's relations. So, if one column
-in your class C<belongs_to> foo and another C<belongs_to> bar, you can do
-C<< join => [qw/ foo bar /] >> to join both (and e.g. use them for C<order_by>).
-If a foo contains many margles and you want to join those too, you can do
-C<< join => { foo => 'margle' } >>. If you want to fetch the columns from the
-related table as well, see C<prefetch> below.
+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
-object(s), because it saves a query. Currently limited to prefetching
+"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
+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 your foot off!
+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 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
+For a paged resultset, how many rows per page. Can also be used to simulate an
+SQL C<LIMIT>.
-=head2 group_by
+=head2 group_by (arrayref)
-A list of columns to group by (note that 'count' doesn't work on grouped
-resultsets)
+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
+Set to 1 to group by all columns.
+
+For more examples of using these attributes, see
+L<DBIx::Class::Manual::Cookbook>.
=cut