holding the foreign key. If $cond is not given, the relname is used as
the column name.
+ Cascading deletes are off per default on a C<belongs_to> relationship, to turn
+ them on, pass C<< cascade_delete => 1 >> in the $attr hashref.
+
NOTE: If you are used to L<Class::DBI> relationships, this is the equivalent
of C<has_a>.
{ prefetch => [qw/book/],
});
my @book_objs = $obj->books;
+ my $books_rs = $obj->books;
+ ( $books_rs ) = $obj->books_rs;
$obj->add_to_books(\%col_data);
columns. You should pass the name of the column in the foreign class as the
$cond argument, or specify a complete join condition.
-As well as the accessor method, a method named C<< add_to_<relname> >>
-will also be added to your Row items, this allows you to insert new
-related items, using the same mechanism as in L<DBIx::Class::Relationship::Base/"create_related">.
+Three methods are created when you create a has_many relationship. The first
+method is the expected accessor method. The second is almost exactly the same
+as the accessor method but "_rs" is added to the end of the method name. This
+method works just like the normal accessor, except that it returns a resultset
+no matter what, even in list context. The third method, named
+C<< add_to_<relname> >>, will also be added to your Row items, this allows
+you to insert new related items, using the same mechanism as in
+L<DBIx::Class::Relationship::Base/"create_related">.
If you delete an object in a class with a C<has_many> relationship, all
- related objects will be deleted as well. However, any database-level
- cascade or restrict will take precedence.
+ the related objects will be deleted as well. However, any database-level
+ cascade or restrict will take precedence. To turn this behavior off, pass
+ C<< cascade_delete => 0 >> in the $attr hashref.
=head2 might_have
If you update or delete an object in a class with a C<might_have>
relationship, the related object will be updated or deleted as well.
Any database-level update or delete constraints will override this behaviour.
+ To turn off this behavior, add C<< cascade_delete => 0 >> to the $attr hashref.
=head2 has_one
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/);
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';
}
}
- return (wantarray ? $rs->all : $rs);
+ return $rs;
}
=head2 search_literal
=back
-Finds a row based on its primary key or unique constraint. For example:
+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);
-Also takes an optional C<key> attribute, to search by a specific key or unique
-constraint. For example:
+You can also find a row by a specific unique constraint using the C<key>
+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 = $schema->resultset('CD')->find(
{
{ key => 'artist_title' }
);
-See also L</find_or_create> and L</update_or_create>.
+If no C<key> is specified and you explicitly name columns, it searches on all
+unique constraints defined on the source, including the primary key.
+
+If the C<key> is specified as C<primary>, it searches only on the primary key.
+
+See also L</find_or_create> and L</update_or_create>. For information on how to
+declare unique constraints, see
+L<DBIx::Class::ResultSource/add_unique_constraint>.
=cut
sub find {
- my ($self, @vals) = @_;
- my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {});
+ my $self = shift;
+ my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
- my @cols = $self->result_source->primary_columns;
- if (exists $attrs->{key}) {
- my %uniq = $self->result_source->unique_constraints;
+ # 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(
- "Unknown key $attrs->{key} on '" . $self->result_source->name . "'"
- ) unless exists $uniq{$attrs->{key}};
- @cols = @{ $uniq{$attrs->{key}} };
+ "Arguments to find must be a hashref or match the number of columns in the "
+ . (exists $attrs->{key} ? "$attrs->{key} unique constraint" : "primary key")
+ );
}
- #use Data::Dumper; warn Dumper($attrs, @vals, @cols);
+
+ # 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 @cols;
-
- my $query;
- if (ref $vals[0] eq 'HASH') {
- $query = { %{$vals[0]} };
- } elsif (@cols == @vals) {
- $query = {};
- @{$query}{@cols} = @vals;
- } else {
- $query = {@vals};
- }
- foreach my $key (grep { ! m/\./ } keys %$query) {
- $query->{"$self->{attrs}{alias}.$key"} = delete $query->{$key};
+ ) 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;
}
- #warn Dumper($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);
+ 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
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 find() as an optimisation.
+any records in it; if not returns nothing. Used by L</find> 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
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
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<DBIx::Class::Row/insert> on it.
+
+If you want objects to be saved immediately, use L</find_or_create> 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
{ key => 'artist_title' }
);
-See also L</find> and L</update_or_create>.
+See also L</find> and L</update_or_create>. For information on how to declare
+unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
=cut
If the C<key> is specified as C<primary>, it searches only on the primary key.
-See also L</find> and L</find_or_create>.
+See also L</find> and L</find_or_create>. For information on how to declare
+unique constraints, see L<DBIx::Class::ResultSource/add_unique_constraint>.
=cut
my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {});
my $hash = ref $_[0] eq 'HASH' ? shift : {@_};
- my %unique_constraints = $self->result_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);
- }
-
- if (@unique_hashes) {
- my $row = $self->single(\@unique_hashes);
- if (defined $row) {
- $row->update($hash);
- return $row;
- }
+ my $row = $self->find($hash, $attrs);
+ if (defined $row) {
+ $row->update($hash);
+ return $row;
}
return $self->create($hash);
You can create your own accessors if required - see
L<DBIx::Class::Manual::Cookbook> for details.
+ Please note: This will NOT insert an C<AS employee_count> into the SQL statement
+ produced, it is used for internal access only. Thus attempting to use the accessor
+ in an C<order_by> clause or similar will fail misrably.
+
=head2 join
=over 4
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