1 package DBIx::Class::ResultSource;
6 use DBIx::Class::ResultSet;
7 use Carp::Clan qw/^DBIx::Class/;
11 use base qw/DBIx::Class/;
12 __PACKAGE__->load_components(qw/AccessorGroup/);
14 __PACKAGE__->mk_group_accessors('simple' =>
15 qw/_ordered_columns _columns _primaries _unique_constraints name resultset_attributes schema from _relationships/);
16 __PACKAGE__->mk_group_accessors('component_class' => qw/resultset_class result_class/);
20 DBIx::Class::ResultSource - Result source object
26 A ResultSource is a component of a schema from which results can be directly
27 retrieved, most usually a table (see L<DBIx::Class::ResultSource::Table>)
34 my ($class, $attrs) = @_;
35 $class = ref $class if ref $class;
36 my $new = bless({ %{$attrs || {}} }, $class);
37 $new->{resultset_class} ||= 'DBIx::Class::ResultSet';
38 $new->{resultset_attributes} = { %{$new->{resultset_attributes} || {}} };
39 $new->{_ordered_columns} = [ @{$new->{_ordered_columns}||[]}];
40 $new->{_columns} = { %{$new->{_columns}||{}} };
41 $new->{_relationships} = { %{$new->{_relationships}||{}} };
42 $new->{name} ||= "!!NAME NOT SET!!";
43 $new->{_columns_info_loaded} ||= 0;
51 $table->add_columns(qw/col1 col2 col3/);
53 $table->add_columns('col1' => \%col1_info, 'col2' => \%col2_info, ...);
55 Adds columns to the result source. If supplied key => hashref pairs uses
56 the hashref as the column_info for that column.
58 Repeated calls of this method will add more columns, not replace them.
60 The contents of the column_info are not set in stone, the following
61 keys are currently recognised/used by DBIx::Class.
67 Use this to set the name of the accessor for this column. If unset,
68 the name of the column will be used.
72 This contains the column type, it is automatically filled by the
73 L<SQL::Translator::Producer::DBIx::Class::File> producer, and the
74 L<DBIx::Class::Schema::Loader> module. If you do not enter the
75 data_type, DBIx::Class will attempt to retrieve it from the
76 database for you, using L<DBI>s column_info method. The values of this
77 key are typically upper-cased.
79 Currently there is no standard set of values for the data_type, use
80 whatever your database(s) support.
84 The length of your column, if it is a column type that can have a size
85 restriction. This is currently not used by DBIx::Class.
89 If the column is allowed to contain NULL values, set a true value
90 (typically 1), here. This is currently not used by DBIx::Class.
92 =item is_auto_increment
94 Set this to a true value if this is a column that is somehow
95 automatically filled. This is currently not used by DBIx::Class.
99 Set this to a true value if this column represents a key from a
100 foreign table. This is currently not used by DBIx::Class.
104 Set this to the default value which will be inserted into this column
105 by the database. Can contain either values or functions. This is
106 currently not used by DBIx::Class.
110 If your column is using a sequence to create it's values, set the name
111 of the sequence here, to allow the values to be retrieved
112 automatically by the L<DBIx::Class::PK::Auto> module. PK::Auto will
113 attempt to retrieve the sequence name from the database, if this value
120 $table->add_column('col' => \%info?);
122 Convenience alias to add_columns
127 my ($self, @cols) = @_;
128 $self->_ordered_columns( \@cols )
129 if !$self->_ordered_columns;
131 my $columns = $self->_columns;
132 while (my $col = shift @cols) {
134 my $column_info = ref $cols[0] ? shift(@cols) : {};
135 # If next entry is { ... } use that for the column info, if not
136 # use an empty hashref
138 push(@added, $col) unless exists $columns->{$col};
140 $columns->{$col} = $column_info;
142 push @{ $self->_ordered_columns }, @added;
146 *add_column = \&add_columns;
150 if ($obj->has_column($col)) { ... }
152 Returns 1 if the source has a column of this name, 0 otherwise.
157 my ($self, $column) = @_;
158 return exists $self->_columns->{$column};
163 my $info = $obj->column_info($col);
165 Returns the column metadata hashref for a column. See the description
166 of add_column for information on the contents of the hashref.
171 my ($self, $column) = @_;
172 $self->throw_exception("No such column $column")
173 unless exists $self->_columns->{$column};
174 #warn $self->{_columns_info_loaded}, "\n";
175 if ( ! $self->_columns->{$column}->{data_type}
176 && ! $self->{_columns_info_loaded}
177 && $self->schema && $self->storage() ){
178 $self->{_columns_info_loaded}++;
180 ############ eval for the case of storage without table
182 $info = $self->storage->columns_info_for ( $self->from() );
185 for my $col ( keys %{$self->_columns} ){
186 for my $i ( keys %{$info->{$col}} ){
187 $self->_columns()->{$col}->{$i} = $info->{$col}->{$i};
192 return $self->_columns->{$column};
197 my @column_names = $obj->columns;
199 Returns all column names in the order they were declared to add_columns
205 $self->throw_exception("columns() is a read-only accessor, did you mean add_columns()?") if (@_ > 1);
206 return @{$self->{_ordered_columns}||[]};
209 =head2 set_primary_key(@cols)
211 Defines one or more columns as primary key for this source. Should be
212 called after C<add_columns>.
214 Additionally, defines a unique constraint named C<primary>.
216 The primary key columns are used by L<DBIx::Class::PK::Auto> to
217 retrieve automatically created values from the database.
221 sub set_primary_key {
222 my ($self, @cols) = @_;
223 # check if primary key columns are valid columns
225 $self->throw_exception("No such column $_ on table ".$self->name)
226 unless $self->has_column($_);
228 $self->_primaries(\@cols);
230 $self->add_unique_constraint(primary => \@cols);
233 =head2 primary_columns
235 Read-only accessor which returns the list of primary keys.
239 sub primary_columns {
240 return @{shift->_primaries||[]};
243 =head2 add_unique_constraint
245 Declare a unique constraint on this source. Call once for each unique
246 constraint. Unique constraints are used when you call C<find> on a
247 L<DBIx::Class::ResultSet>, only columns in the constraint are searched,
249 # For e.g. UNIQUE (column1, column2)
250 __PACKAGE__->add_unique_constraint(constraint_name => [ qw/column1 column2/ ]);
254 sub add_unique_constraint {
255 my ($self, $name, $cols) = @_;
258 $self->throw_exception("No such column $_ on table ".$self->name)
259 unless $self->has_column($_);
262 my %unique_constraints = $self->unique_constraints;
263 $unique_constraints{$name} = $cols;
264 $self->_unique_constraints(\%unique_constraints);
267 =head2 unique_constraints
269 Read-only accessor which returns the list of unique constraints on this source.
273 sub unique_constraints {
274 return %{shift->_unique_constraints||{}};
279 Returns an expression of the source to be supplied to storage to specify
280 retrieval from this source; in the case of a database the required FROM clause
287 Returns the storage handle for the current schema.
289 See also: L<DBIx::Class::Storage>
293 sub storage { shift->schema->storage; }
295 =head2 add_relationship
297 $source->add_relationship('relname', 'related_source', $cond, $attrs);
299 The relation name can be arbitrary, but must be unique for each relationship
300 attached to this result source. 'related_source' should be the name with
301 which the related result source was registered with the current schema
302 (for simple schemas this is usally either Some::Namespace::Foo or just Foo)
304 The condition needs to be an SQL::Abstract-style representation of the join
305 between the tables. For example, if you're creating a rel from Author to Book,
307 { 'foreign.author_id' => 'self.id' }
309 will result in the JOIN clause
311 author me JOIN book foreign ON foreign.author_id = me.id
313 You can specify as many foreign => self mappings as necessary.
315 Valid attributes are as follows:
321 Explicitly specifies the type of join to use in the relationship. Any
322 SQL join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in
323 the SQL command immediately before C<JOIN>.
327 An arrayref containing a list of accessors in the foreign class to
328 proxy in the main class. If, for example, you do the following:
330 __PACKAGE__->might_have(bar => 'Bar', undef, { proxy => [ qw/margle/] });
332 Then, assuming Bar has an accessor named margle, you can do:
334 my $obj = Foo->find(1);
335 $obj->margle(10); # set margle; Bar object is created if it doesn't exist
339 Specifies the type of accessor that should be created for the
340 relationship. Valid values are C<single> (for when there is only a single
341 related object), C<multi> (when there can be many), and C<filter> (for
342 when there is a single related object, but you also want the relationship
343 accessor to double as a column accessor). For C<multi> accessors, an
344 add_to_* method is also created, which calls C<create_related> for the
351 sub add_relationship {
352 my ($self, $rel, $f_source_name, $cond, $attrs) = @_;
353 $self->throw_exception("Can't create relationship without join condition") unless $cond;
356 my %rels = %{ $self->_relationships };
357 $rels{$rel} = { class => $f_source_name,
358 source => $f_source_name,
361 $self->_relationships(\%rels);
365 # XXX disabled. doesn't work properly currently. skip in tests.
367 my $f_source = $self->schema->source($f_source_name);
369 eval "require $f_source_name;";
371 die $@ unless $@ =~ /Can't locate/;
373 $f_source = $f_source_name->result_source;
374 #my $s_class = ref($self->schema);
375 #$f_source_name =~ m/^${s_class}::(.*)$/;
376 #$self->schema->register_class(($1 || $f_source_name), $f_source_name);
377 #$f_source = $self->schema->source($f_source_name);
379 return unless $f_source; # Can't test rel without f_source
381 eval { $self->resolve_join($rel, 'me') };
383 if ($@) { # If the resolve failed, back out and re-throw the error
384 delete $rels{$rel}; #
385 $self->_relationships(\%rels);
386 $self->throw_exception("Error creating relationship $rel: $@");
391 =head2 relationships()
393 Returns all valid relationship names for this source
398 return keys %{shift->_relationships};
401 =head2 relationship_info($relname)
403 Returns the relationship information for the specified relationship name
407 sub relationship_info {
408 my ($self, $rel) = @_;
409 return $self->_relationships->{$rel};
412 =head2 has_relationship($rel)
414 Returns 1 if the source has a relationship of this name, 0 otherwise.
418 sub has_relationship {
419 my ($self, $rel) = @_;
420 return exists $self->_relationships->{$rel};
423 =head2 resolve_join($relation)
425 Returns the join structure required for the related result source
430 my ($self, $join, $alias, $seen) = @_;
432 if (ref $join eq 'ARRAY') {
433 return map { $self->resolve_join($_, $alias, $seen) } @$join;
434 } elsif (ref $join eq 'HASH') {
437 my $as = ($seen->{$_} ? $_.'_'.($seen->{$_}+1) : $_);
438 ($self->resolve_join($_, $alias, $seen),
439 $self->related_source($_)->resolve_join($join->{$_}, $as, $seen));
441 } elsif (ref $join) {
442 $self->throw_exception("No idea how to resolve join reftype ".ref $join);
444 my $count = ++$seen->{$join};
445 #use Data::Dumper; warn Dumper($seen);
446 my $as = ($count > 1 ? "${join}_${count}" : $join);
447 my $rel_info = $self->relationship_info($join);
448 $self->throw_exception("No such relationship ${join}") unless $rel_info;
449 my $type = $rel_info->{attrs}{join_type} || '';
450 return [ { $as => $self->related_source($join)->from,
451 -join_type => $type },
452 $self->resolve_condition($rel_info->{cond}, $as, $alias) ];
456 =head2 resolve_condition($cond, $as, $alias|$object)
458 Resolves the passed condition to a concrete query fragment. If given an alias,
459 returns a join condition; if given an object, inverts that object to produce
460 a related conditional from that object.
464 sub resolve_condition {
465 my ($self, $cond, $as, $for) = @_;
467 if (ref $cond eq 'HASH') {
469 while (my ($k, $v) = each %{$cond}) {
470 # XXX should probably check these are valid columns
471 $k =~ s/^foreign\.// || $self->throw_exception("Invalid rel cond key ${k}");
472 $v =~ s/^self\.// || $self->throw_exception("Invalid rel cond val ${v}");
473 if (ref $for) { # Object
474 #warn "$self $k $for $v";
475 $ret{$k} = $for->get_column($v);
478 $ret{"${as}.${k}"} = "${for}.${v}";
482 } elsif (ref $cond eq 'ARRAY') {
483 return [ map { $self->resolve_condition($_, $as, $for) } @$cond ];
485 die("Can't handle this yet :(");
489 =head2 resolve_prefetch (hashref/arrayref/scalar)
491 Accepts one or more relationships for the current source and returns an
492 array of column names for each of those relationships. Column names are
493 prefixed relative to the current source, in accordance with where they appear
494 in the supplied relationships. Examples:
496 my $source = $schema->resultset('Tag')->source;
497 @columns = $source->resolve_prefetch( { cd => 'artist' } );
505 # 'cd.artist.artistid',
509 @columns = $source->resolve_prefetch( qw[/ cd /] );
519 $source = $schema->resultset('CD')->source;
520 @columns = $source->resolve_prefetch( qw[/ artist producer /] );
526 # 'producer.producerid',
532 sub resolve_prefetch {
533 my ($self, $pre, $alias, $seen) = @_;
536 #$alias ||= $self->name;
537 #warn $alias, Dumper $pre;
538 if( ref $pre eq 'ARRAY' ) {
539 return map { $self->resolve_prefetch( $_, $alias, $seen ) } @$pre;
541 elsif( ref $pre eq 'HASH' ) {
544 $self->resolve_prefetch($_, $alias, $seen),
545 $self->related_source($_)->resolve_prefetch(
546 $pre->{$_}, "${alias}.$_", $seen)
552 $self->throw_exception( "don't know how to resolve prefetch reftype " . ref $pre);
555 my $count = ++$seen->{$pre};
556 my $as = ($count > 1 ? "${pre}_${count}" : $pre);
557 my $rel_info = $self->relationship_info( $pre );
558 $self->throw_exception( $self->name . " has no such relationship '$pre'" ) unless $rel_info;
559 my $as_prefix = ($alias =~ /^.*?\.(.*)$/ ? $1.'.' : '');
560 return map { [ "${as}.$_", "${as_prefix}${pre}.$_", ] }
561 $self->related_source($pre)->columns;
562 #warn $alias, Dumper (\@ret);
567 =head2 related_source($relname)
569 Returns the result source object for the given relationship
574 my ($self, $rel) = @_;
575 if( !$self->has_relationship( $rel ) ) {
576 $self->throw_exception("No such relationship '$rel'");
578 return $self->schema->source($self->relationship_info($rel)->{source});
583 Returns a resultset for the given source, by calling:
585 $self->resultset_class->new($self, $self->resultset_attributes)
587 =head2 resultset_class
589 Set the class of the resultset, this is useful if you want to create your
590 own resultset methods. Create your own class derived from
591 L<DBIx::Class::ResultSet>, and set it here.
593 =head2 resultset_attributes
595 Specify here any attributes you wish to pass to your specialised resultset.
601 return $self->resultset_class->new($self, $self->{resultset_attributes});
604 =head2 throw_exception
606 See throw_exception in L<DBIx::Class::Schema>.
610 sub throw_exception {
612 if (defined $self->schema) {
613 $self->schema->throw_exception(@_);
622 Matt S. Trout <mst@shadowcatsystems.co.uk>
626 You may distribute this code under the same terms as Perl itself.