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55e2d745 |
1 | package DBIx::Class::Relationship::Base; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
1edd1722 |
6 | use base qw/DBIx::Class/; |
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7 | |
8 | use Scalar::Util qw/weaken blessed/; |
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9 | use Try::Tiny; |
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10 | use namespace::clean; |
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11 | |
75d07914 |
12 | =head1 NAME |
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13 | |
8918977e |
14 | DBIx::Class::Relationship::Base - Inter-table relationships |
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15 | |
16 | =head1 SYNOPSIS |
17 | |
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18 | __PACKAGE__->add_relationship( |
19 | spiders => 'My::DB::Result::Creatures', |
20 | sub { |
21 | my $args = shift; |
22 | return { |
23 | "$args->{foreign_alias}.id" => { -ident => "$args->{self_alias}.id" }, |
24 | "$args->{foreign_alias}.type" => 'arachnid' |
25 | }; |
26 | }, |
27 | ); |
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28 | |
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29 | =head1 DESCRIPTION |
30 | |
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31 | This class provides methods to describe the relationships between the |
32 | tables in your database model. These are the "bare bones" relationships |
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33 | methods, for predefined ones, look in L<DBIx::Class::Relationship>. |
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34 | |
35 | =head1 METHODS |
36 | |
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37 | =head2 add_relationship |
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38 | |
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39 | =over 4 |
40 | |
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41 | =item Arguments: 'relname', 'Foreign::Class', $condition, $attrs |
27f01d1f |
42 | |
43 | =back |
30236e47 |
44 | |
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45 | __PACKAGE__->add_relationship('relname', |
46 | 'Foreign::Class', |
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47 | $condition, $attrs); |
48 | |
49 | Create a custom relationship between one result source and another |
50 | source, indicated by its class name. |
503536d5 |
51 | |
406734bb |
52 | =head3 condition |
53 | |
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54 | The condition argument describes the C<ON> clause of the C<JOIN> |
55 | expression used to connect the two sources when creating SQL queries. |
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56 | |
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57 | To create simple equality joins, supply a hashref containing the |
58 | remote table column name as the key(s), and the local table column |
6c4f4d69 |
59 | name as the value(s), for example given: |
503536d5 |
60 | |
6c4f4d69 |
61 | My::Schema::Author->has_many( |
62 | books => 'My::Schema::Book', |
63 | { 'foreign.author_id' => 'self.id' } |
64 | ); |
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65 | |
6c4f4d69 |
66 | A query like: |
67 | |
68 | $author_rs->search_related('books')->next |
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69 | |
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70 | will result in the following C<JOIN> clause: |
71 | |
72 | ... FROM author me LEFT JOIN book books ON books.author_id = me.id ... |
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73 | |
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74 | This describes a relationship between the C<Author> table and the |
75 | C<Book> table where the C<Book> table has a column C<author_id> |
76 | containing the ID value of the C<Author>. |
77 | |
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78 | C<foreign> and C<self> are pseudo aliases and must be entered |
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79 | literally. They will be replaced with the actual correct table alias |
80 | when the SQL is produced. |
81 | |
82 | Similarly: |
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83 | |
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84 | My::Schema::Book->has_many( |
85 | editions => 'My::Schema::Edition', |
86 | { |
87 | 'foreign.publisher_id' => 'self.publisher_id', |
88 | 'foreign.type_id' => 'self.type_id', |
89 | } |
90 | ); |
91 | |
92 | ... |
93 | |
94 | $book_rs->search_related('editions')->next |
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95 | |
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96 | will result in the C<JOIN> clause: |
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97 | |
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98 | ... FROM book me |
99 | LEFT JOIN edition editions ON |
100 | editions.publisher_id = me.publisher_id |
101 | AND editions.type_id = me.type_id ... |
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102 | |
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103 | This describes the relationship from C<Book> to C<Edition>, where the |
104 | C<Edition> table refers to a publisher and a type (e.g. "paperback"): |
105 | |
106 | As is the default in L<SQL::Abstract>, the key-value pairs will be |
107 | C<AND>ed in the result. C<OR> can be achieved with an arrayref, for |
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108 | example a condition like: |
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109 | |
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110 | My::Schema::Item->has_many( |
111 | related_item_links => My::Schema::Item::Links, |
112 | [ |
113 | { 'foreign.left_itemid' => 'self.id' }, |
114 | { 'foreign.right_itemid' => 'self.id' }, |
115 | ], |
116 | ); |
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117 | |
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118 | will translate to the following C<JOIN> clause: |
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119 | |
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120 | ... FROM item me JOIN item_relations related_item_links ON |
121 | related_item_links.left_itemid = me.id |
122 | OR related_item_links.right_itemid = me.id ... |
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123 | |
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124 | This describes the relationship from C<Item> to C<Item::Links>, where |
125 | C<Item::Links> is a many-to-many linking table, linking items back to |
126 | themselves in a peer fashion (without a "parent-child" designation) |
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127 | |
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128 | To specify joins which describe more than a simple equality of column |
129 | values, the custom join condition coderef syntax can be used. For |
130 | example: |
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131 | |
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132 | My::Schema::Artist->has_many( |
133 | cds_80s => 'My::Schema::CD', |
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134 | sub { |
6c4f4d69 |
135 | my $args = shift; |
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136 | |
6c4f4d69 |
137 | return { |
138 | "$args->{foreign_alias}.artist" => { -ident => "$args->{self_alias}.artistid" }, |
139 | "$args->{foreign_alias}.year" => { '>', "1979", '<', "1990" }, |
140 | }; |
141 | } |
142 | ); |
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143 | |
6c4f4d69 |
144 | ... |
13523f29 |
145 | |
6c4f4d69 |
146 | $artist_rs->search_related('cds_80s')->next; |
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147 | |
6c4f4d69 |
148 | will result in the C<JOIN> clause: |
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149 | |
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150 | ... FROM artist me LEFT JOIN cd cds_80s ON |
151 | cds_80s.artist = me.artistid |
152 | AND cds_80s.year < ? |
153 | AND cds_80s.year > ? |
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154 | |
6c4f4d69 |
155 | with the bind values: |
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156 | |
6c4f4d69 |
157 | '1990', '1979' |
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158 | |
6c4f4d69 |
159 | C<< $args->{foreign_alias} >> and C<< $args->{self_alias} >> are supplied the |
160 | same values that would be otherwise substituted for C<foreign> and C<self> |
161 | in the simple hashref syntax case. |
162 | |
163 | The coderef is expected to return a valid L<SQL::Abstract> query-structure, just |
164 | like what one would supply as the first argument to |
165 | L<DBIx::Class::ResultSet/search>. The return value will be passed directly to |
166 | L<SQL::Abstract> and the resulting SQL will be used verbatim as the C<ON> |
167 | clause of the C<JOIN> statement associated with this relationship. |
168 | |
169 | While every coderef-based condition must return a valid C<ON> clause, it may |
170 | elect to additionally return a simplified join-free condition hashref when |
171 | invoked as C<< $row_object->relationship >>, as opposed to |
172 | C<< $rs->related_resultset('relationship') >>. In this case C<$row_object> is |
173 | passed to the coderef as C<< $args->{self_rowobj} >>, so a user can do the |
174 | following: |
175 | |
176 | sub { |
177 | my $args = shift; |
178 | |
179 | return ( |
180 | { |
181 | "$args->{foreign_alias}.artist" => { -ident => "$args->{self_alias}.artistid" }, |
182 | "$args->{foreign_alias}.year" => { '>', "1979", '<', "1990" }, |
183 | }, |
184 | $args->{self_rowobj} && { |
185 | "$args->{foreign_alias}.artist" => $args->{self_rowobj}->artistid, |
186 | "$args->{foreign_alias}.year" => { '>', "1979", '<', "1990" }, |
187 | }, |
188 | ); |
13523f29 |
189 | } |
190 | |
191 | Now this code: |
192 | |
193 | my $artist = $schema->resultset("Artist")->find({ id => 4 }); |
194 | $artist->cds_80s->all; |
195 | |
6c4f4d69 |
196 | Can skip a C<JOIN> altogether and instead produce: |
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197 | |
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198 | SELECT cds_80s.cdid, cds_80s.artist, cds_80s.title, cds_80s.year, cds_80s.genreid, cds_80s.single_track |
199 | FROM cd cds_80s |
200 | WHERE cds_80s.artist = ? |
201 | AND cds_80s.year < ? |
202 | AND cds_80s.year > ? |
13523f29 |
203 | |
204 | With the bind values: |
205 | |
206 | '4', '1990', '1979' |
207 | |
6c4f4d69 |
208 | Note that in order to be able to use |
209 | L<< $row->create_related|DBIx::Class::Relationship::Base/create_related >>, |
210 | the coderef must not only return as its second such a "simple" condition |
211 | hashref which does not depend on joins being available, but the hashref must |
212 | contain only plain values/deflatable objects, such that the result can be |
213 | passed directly to L<DBIx::Class::Relationship::Base/set_from_related>. For |
214 | instance the C<year> constraint in the above example prevents the relationship |
215 | from being used to to create related objects (an exception will be thrown). |
216 | |
217 | In order to allow the user to go truly crazy when generating a custom C<ON> |
218 | clause, the C<$args> hashref passed to the subroutine contains some extra |
219 | metadata. Currently the supplied coderef is executed as: |
220 | |
221 | $relationship_info->{cond}->({ |
222 | self_alias => The alias of the invoking resultset ('me' in case of a row object), |
223 | foreign_alias => The alias of the to-be-joined resultset (often matches relname), |
224 | self_resultsource => The invocant's resultsource, |
225 | foreign_relname => The relationship name (does *not* always match foreign_alias), |
226 | self_rowobj => The invocant itself in case of $row_obj->relationship |
227 | }); |
8091aa91 |
228 | |
406734bb |
229 | =head3 attributes |
230 | |
231 | The L<standard ResultSet attributes|DBIx::Class::ResultSet/ATTRIBUTES> may |
232 | be used as relationship attributes. In particular, the 'where' attribute is |
233 | useful for filtering relationships: |
234 | |
235 | __PACKAGE__->has_many( 'valid_users', 'MyApp::Schema::User', |
236 | { 'foreign.user_id' => 'self.user_id' }, |
237 | { where => { valid => 1 } } |
238 | ); |
239 | |
240 | The following attributes are also valid: |
8091aa91 |
241 | |
242 | =over 4 |
243 | |
244 | =item join_type |
245 | |
246 | Explicitly specifies the type of join to use in the relationship. Any SQL |
247 | join type is valid, e.g. C<LEFT> or C<RIGHT>. It will be placed in the SQL |
248 | command immediately before C<JOIN>. |
249 | |
97c96475 |
250 | =item proxy =E<gt> $column | \@columns | \%column |
251 | |
252 | =over 4 |
253 | |
254 | =item \@columns |
8091aa91 |
255 | |
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256 | An arrayref containing a list of accessors in the foreign class to create in |
8091aa91 |
257 | the main class. If, for example, you do the following: |
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258 | |
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259 | MyApp::Schema::CD->might_have(liner_notes => 'MyApp::Schema::LinerNotes', |
27f01d1f |
260 | undef, { |
261 | proxy => [ qw/notes/ ], |
262 | }); |
d4daee7b |
263 | |
03460bef |
264 | Then, assuming MyApp::Schema::LinerNotes has an accessor named notes, you can do: |
8091aa91 |
265 | |
03460bef |
266 | my $cd = MyApp::Schema::CD->find(1); |
30236e47 |
267 | $cd->notes('Notes go here'); # set notes -- LinerNotes object is |
268 | # created if it doesn't exist |
d4daee7b |
269 | |
97c96475 |
270 | =item \%column |
271 | |
272 | A hashref where each key is the accessor you want installed in the main class, |
273 | and its value is the name of the original in the fireign class. |
274 | |
03460bef |
275 | MyApp::Schema::Track->belongs_to( cd => 'DBICTest::Schema::CD', 'cd', { |
97c96475 |
276 | proxy => { cd_title => 'title' }, |
277 | }); |
278 | |
279 | This will create an accessor named C<cd_title> on the C<$track> row object. |
280 | |
281 | =back |
282 | |
283 | NOTE: you can pass a nested struct too, for example: |
284 | |
03460bef |
285 | MyApp::Schema::Track->belongs_to( cd => 'DBICTest::Schema::CD', 'cd', { |
97c96475 |
286 | proxy => [ 'year', { cd_title => 'title' } ], |
287 | }); |
288 | |
8091aa91 |
289 | =item accessor |
290 | |
291 | Specifies the type of accessor that should be created for the relationship. |
292 | Valid values are C<single> (for when there is only a single related object), |
293 | C<multi> (when there can be many), and C<filter> (for when there is a single |
294 | related object, but you also want the relationship accessor to double as |
295 | a column accessor). For C<multi> accessors, an add_to_* method is also |
296 | created, which calls C<create_related> for the relationship. |
297 | |
3d618782 |
298 | =item is_foreign_key_constraint |
299 | |
300 | If you are using L<SQL::Translator> to create SQL for you and you find that it |
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301 | is creating constraints where it shouldn't, or not creating them where it |
3d618782 |
302 | should, set this attribute to a true or false value to override the detection |
303 | of when to create constraints. |
304 | |
5f7ac523 |
305 | =item cascade_copy |
306 | |
307 | If C<cascade_copy> is true on a C<has_many> relationship for an |
308 | object, then when you copy the object all the related objects will |
fd323bf1 |
309 | be copied too. To turn this behaviour off, pass C<< cascade_copy => 0 >> |
310 | in the C<$attr> hashref. |
b7bbc39f |
311 | |
312 | The behaviour defaults to C<< cascade_copy => 1 >> for C<has_many> |
313 | relationships. |
5f7ac523 |
314 | |
315 | =item cascade_delete |
316 | |
b7bbc39f |
317 | By default, DBIx::Class cascades deletes across C<has_many>, |
318 | C<has_one> and C<might_have> relationships. You can disable this |
fd323bf1 |
319 | behaviour on a per-relationship basis by supplying |
b7bbc39f |
320 | C<< cascade_delete => 0 >> in the relationship attributes. |
5f7ac523 |
321 | |
322 | The cascaded operations are performed after the requested delete, |
323 | so if your database has a constraint on the relationship, it will |
324 | have deleted/updated the related records or raised an exception |
325 | before DBIx::Class gets to perform the cascaded operation. |
326 | |
327 | =item cascade_update |
328 | |
b7bbc39f |
329 | By default, DBIx::Class cascades updates across C<has_one> and |
5f7ac523 |
330 | C<might_have> relationships. You can disable this behaviour on a |
b7bbc39f |
331 | per-relationship basis by supplying C<< cascade_update => 0 >> in |
332 | the relationship attributes. |
5f7ac523 |
333 | |
cee0c9b1 |
334 | This is not a RDMS style cascade update - it purely means that when |
335 | an object has update called on it, all the related objects also |
336 | have update called. It will not change foreign keys automatically - |
337 | you must arrange to do this yourself. |
5f7ac523 |
338 | |
e377d723 |
339 | =item on_delete / on_update |
340 | |
341 | If you are using L<SQL::Translator> to create SQL for you, you can use these |
fd323bf1 |
342 | attributes to explicitly set the desired C<ON DELETE> or C<ON UPDATE> constraint |
343 | type. If not supplied the SQLT parser will attempt to infer the constraint type by |
e377d723 |
344 | interrogating the attributes of the B<opposite> relationship. For any 'multi' |
fd323bf1 |
345 | relationship with C<< cascade_delete => 1 >>, the corresponding belongs_to |
346 | relationship will be created with an C<ON DELETE CASCADE> constraint. For any |
e377d723 |
347 | relationship bearing C<< cascade_copy => 1 >> the resulting belongs_to constraint |
348 | will be C<ON UPDATE CASCADE>. If you wish to disable this autodetection, and just |
fd323bf1 |
349 | use the RDBMS' default constraint type, pass C<< on_delete => undef >> or |
e377d723 |
350 | C<< on_delete => '' >>, and the same for C<on_update> respectively. |
351 | |
13de943d |
352 | =item is_deferrable |
353 | |
354 | Tells L<SQL::Translator> that the foreign key constraint it creates should be |
355 | deferrable. In other words, the user may request that the constraint be ignored |
356 | until the end of the transaction. Currently, only the PostgreSQL producer |
357 | actually supports this. |
358 | |
2581038c |
359 | =item add_fk_index |
360 | |
361 | Tells L<SQL::Translator> to add an index for this constraint. Can also be |
362 | specified globally in the args to L<DBIx::Class::Schema/deploy> or |
363 | L<DBIx::Class::Schema/create_ddl_dir>. Default is on, set to 0 to disable. |
364 | |
8091aa91 |
365 | =back |
366 | |
87c4e602 |
367 | =head2 register_relationship |
368 | |
27f01d1f |
369 | =over 4 |
370 | |
ebc77b53 |
371 | =item Arguments: $relname, $rel_info |
27f01d1f |
372 | |
373 | =back |
71e65b39 |
374 | |
30236e47 |
375 | Registers a relationship on the class. This is called internally by |
71f9df37 |
376 | DBIx::Class::ResultSourceProxy to set up Accessors and Proxies. |
71e65b39 |
377 | |
55e2d745 |
378 | =cut |
379 | |
71e65b39 |
380 | sub register_relationship { } |
381 | |
27f01d1f |
382 | =head2 related_resultset |
383 | |
384 | =over 4 |
385 | |
ebc77b53 |
386 | =item Arguments: $relationship_name |
27f01d1f |
387 | |
d601dc88 |
388 | =item Return Value: $related_resultset |
27f01d1f |
389 | |
390 | =back |
30236e47 |
391 | |
27f01d1f |
392 | $rs = $cd->related_resultset('artist'); |
30236e47 |
393 | |
27f01d1f |
394 | Returns a L<DBIx::Class::ResultSet> for the relationship named |
395 | $relationship_name. |
30236e47 |
396 | |
397 | =cut |
398 | |
399 | sub related_resultset { |
400 | my $self = shift; |
bc0c9800 |
401 | $self->throw_exception("Can't call *_related as class methods") |
402 | unless ref $self; |
30236e47 |
403 | my $rel = shift; |
164efde3 |
404 | my $rel_info = $self->relationship_info($rel); |
bc0c9800 |
405 | $self->throw_exception( "No such relationship ${rel}" ) |
164efde3 |
406 | unless $rel_info; |
d4daee7b |
407 | |
30236e47 |
408 | return $self->{related_resultsets}{$rel} ||= do { |
409 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
164efde3 |
410 | $attrs = { %{$rel_info->{attrs} || {}}, %$attrs }; |
30236e47 |
411 | |
bc0c9800 |
412 | $self->throw_exception( "Invalid query: @_" ) |
413 | if (@_ > 1 && (@_ % 2 == 1)); |
30236e47 |
414 | my $query = ((@_ > 1) ? {@_} : shift); |
415 | |
68f3b0dd |
416 | my $source = $self->result_source; |
d419ded6 |
417 | |
418 | # condition resolution may fail if an incomplete master-object prefetch |
34b6b86f |
419 | # is encountered - that is ok during prefetch construction (not yet in_storage) |
aa56106b |
420 | my ($cond, $is_crosstable) = try { |
16053767 |
421 | $source->_resolve_condition( $rel_info->{cond}, $rel, $self, $rel ) |
52b420dd |
422 | } |
ed7ab0f4 |
423 | catch { |
34b6b86f |
424 | if ($self->in_storage) { |
ed7ab0f4 |
425 | $self->throw_exception ($_); |
34b6b86f |
426 | } |
52b420dd |
427 | |
428 | $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION; # RV |
ed7ab0f4 |
429 | }; |
d419ded6 |
430 | |
aa56106b |
431 | # keep in mind that the following if() block is part of a do{} - no return()s!!! |
432 | if ($is_crosstable) { |
433 | $self->throw_exception ( |
434 | "A cross-table relationship condition returned for statically declared '$rel'") |
435 | unless ref $rel_info->{cond} eq 'CODE'; |
436 | |
437 | # A WHOREIFFIC hack to reinvoke the entire condition resolution |
438 | # with the correct alias. Another way of doing this involves a |
439 | # lot of state passing around, and the @_ positions are already |
440 | # mapped out, making this crap a less icky option. |
441 | # |
442 | # The point of this exercise is to retain the spirit of the original |
443 | # $obj->search_related($rel) where the resulting rset will have the |
444 | # root alias as 'me', instead of $rel (as opposed to invoking |
445 | # $rs->search_related) |
446 | |
aa56106b |
447 | local $source->{_relationships}{me} = $source->{_relationships}{$rel}; # make the fake 'me' rel |
448 | my $obj_table_alias = lc($source->source_name) . '__row'; |
93508f48 |
449 | $obj_table_alias =~ s/\W+/_/g; |
aa56106b |
450 | |
451 | $source->resultset->search( |
452 | $self->ident_condition($obj_table_alias), |
453 | { alias => $obj_table_alias }, |
454 | )->search_related('me', $query, $attrs) |
68f3b0dd |
455 | } |
aa56106b |
456 | else { |
457 | # FIXME - this conditional doesn't seem correct - got to figure out |
458 | # at some point what it does. Also the entire UNRESOLVABLE_CONDITION |
459 | # business seems shady - we could simply not query *at all* |
460 | if ($cond eq $DBIx::Class::ResultSource::UNRESOLVABLE_CONDITION) { |
461 | my $reverse = $source->reverse_relationship_info($rel); |
462 | foreach my $rev_rel (keys %$reverse) { |
463 | if ($reverse->{$rev_rel}{attrs}{accessor} && $reverse->{$rev_rel}{attrs}{accessor} eq 'multi') { |
464 | $attrs->{related_objects}{$rev_rel} = [ $self ]; |
465 | weaken $attrs->{related_object}{$rev_rel}[0]; |
466 | } else { |
467 | $attrs->{related_objects}{$rev_rel} = $self; |
468 | weaken $attrs->{related_object}{$rev_rel}; |
469 | } |
470 | } |
9aae3566 |
471 | } |
aa56106b |
472 | elsif (ref $cond eq 'ARRAY') { |
7689b9e5 |
473 | $cond = [ map { |
474 | if (ref $_ eq 'HASH') { |
475 | my $hash; |
476 | foreach my $key (keys %$_) { |
477 | my $newkey = $key !~ /\./ ? "me.$key" : $key; |
478 | $hash->{$newkey} = $_->{$key}; |
479 | } |
480 | $hash; |
481 | } else { |
482 | $_; |
370f2ba2 |
483 | } |
7689b9e5 |
484 | } @$cond ]; |
aa56106b |
485 | } |
486 | elsif (ref $cond eq 'HASH') { |
487 | foreach my $key (grep { ! /\./ } keys %$cond) { |
7689b9e5 |
488 | $cond->{"me.$key"} = delete $cond->{$key}; |
370f2ba2 |
489 | } |
30236e47 |
490 | } |
a126983e |
491 | |
7689b9e5 |
492 | $query = ($query ? { '-and' => [ $cond, $query ] } : $cond); |
493 | $self->result_source->related_source($rel)->resultset->search( |
aa56106b |
494 | $query, $attrs |
495 | ); |
7689b9e5 |
496 | } |
30236e47 |
497 | }; |
498 | } |
499 | |
8091aa91 |
500 | =head2 search_related |
503536d5 |
501 | |
5b89a768 |
502 | @objects = $rs->search_related('relname', $cond, $attrs); |
503 | $objects_rs = $rs->search_related('relname', $cond, $attrs); |
30236e47 |
504 | |
505 | Run a search on a related resultset. The search will be restricted to the |
506 | item or items represented by the L<DBIx::Class::ResultSet> it was called |
507 | upon. This method can be called on a ResultSet, a Row or a ResultSource class. |
503536d5 |
508 | |
509 | =cut |
510 | |
55e2d745 |
511 | sub search_related { |
ff7bb7a1 |
512 | return shift->related_resultset(shift)->search(@_); |
b52e9bf8 |
513 | } |
514 | |
5b89a768 |
515 | =head2 search_related_rs |
516 | |
517 | ( $objects_rs ) = $rs->search_related_rs('relname', $cond, $attrs); |
518 | |
fd323bf1 |
519 | This method works exactly the same as search_related, except that |
48580715 |
520 | it guarantees a resultset, even in list context. |
5b89a768 |
521 | |
522 | =cut |
523 | |
524 | sub search_related_rs { |
525 | return shift->related_resultset(shift)->search_rs(@_); |
526 | } |
527 | |
b52e9bf8 |
528 | =head2 count_related |
529 | |
7be93b07 |
530 | $obj->count_related('relname', $cond, $attrs); |
b52e9bf8 |
531 | |
bc0c9800 |
532 | Returns the count of all the items in the related resultset, restricted by the |
533 | current item or where conditions. Can be called on a |
27f01d1f |
534 | L<DBIx::Class::Manual::Glossary/"ResultSet"> or a |
bc0c9800 |
535 | L<DBIx::Class::Manual::Glossary/"Row"> object. |
30236e47 |
536 | |
b52e9bf8 |
537 | =cut |
538 | |
539 | sub count_related { |
540 | my $self = shift; |
541 | return $self->search_related(@_)->count; |
55e2d745 |
542 | } |
543 | |
30236e47 |
544 | =head2 new_related |
545 | |
546 | my $new_obj = $obj->new_related('relname', \%col_data); |
547 | |
548 | Create a new item of the related foreign class. If called on a |
fd323bf1 |
549 | L<Row|DBIx::Class::Manual::Glossary/"Row"> object, it will magically |
550 | set any foreign key columns of the new object to the related primary |
551 | key columns of the source object for you. The newly created item will |
479b2a6a |
552 | not be saved into your storage until you call L<DBIx::Class::Row/insert> |
30236e47 |
553 | on it. |
554 | |
555 | =cut |
556 | |
557 | sub new_related { |
558 | my ($self, $rel, $values, $attrs) = @_; |
78b948c3 |
559 | |
560 | # FIXME - this is a bad position for this (also an identical copy in |
561 | # set_from_related), but I have no saner way to hook, and I absolutely |
562 | # want this to throw at least for coderefs, instead of the "insert a NULL |
563 | # when it gets hard" insanity --ribasushi |
564 | # |
565 | # sanity check - currently throw when a complex coderef rel is encountered |
566 | # FIXME - should THROW MOAR! |
567 | |
568 | if (ref $self) { # cdbi calls this as a class method, /me vomits |
569 | |
570 | my $rsrc = $self->result_source; |
571 | my (undef, $crosstable, $relcols) = $rsrc->_resolve_condition ( |
572 | $rsrc->relationship_info($rel)->{cond}, $rel, $self, $rel |
573 | ); |
574 | |
575 | $self->throw_exception("Custom relationship '$rel' does not resolve to a join-free condition fragment") |
576 | if $crosstable; |
577 | |
578 | if (@{$relcols || []} and @$relcols = grep { ! exists $values->{$_} } @$relcols) { |
579 | $self->throw_exception(sprintf ( |
580 | "Custom relationship '%s' not definitive - returns conditions instead of values for column(s): %s", |
581 | $rel, |
582 | map { "'$_'" } @$relcols |
583 | )); |
584 | } |
585 | } |
586 | |
587 | my $row = $self->search_related($rel)->new($values, $attrs); |
588 | return $row; |
30236e47 |
589 | } |
590 | |
8091aa91 |
591 | =head2 create_related |
503536d5 |
592 | |
30236e47 |
593 | my $new_obj = $obj->create_related('relname', \%col_data); |
594 | |
595 | Creates a new item, similarly to new_related, and also inserts the item's data |
596 | into your storage medium. See the distinction between C<create> and C<new> |
597 | in L<DBIx::Class::ResultSet> for details. |
503536d5 |
598 | |
599 | =cut |
600 | |
55e2d745 |
601 | sub create_related { |
3842b955 |
602 | my $self = shift; |
fea3d045 |
603 | my $rel = shift; |
78b948c3 |
604 | my $obj = $self->new_related($rel, @_)->insert; |
64acc2bc |
605 | delete $self->{related_resultsets}->{$rel}; |
606 | return $obj; |
55e2d745 |
607 | } |
608 | |
8091aa91 |
609 | =head2 find_related |
503536d5 |
610 | |
30236e47 |
611 | my $found_item = $obj->find_related('relname', @pri_vals | \%pri_vals); |
612 | |
613 | Attempt to find a related object using its primary key or unique constraints. |
27f01d1f |
614 | See L<DBIx::Class::ResultSet/find> for details. |
503536d5 |
615 | |
616 | =cut |
617 | |
1a14aa3f |
618 | sub find_related { |
619 | my $self = shift; |
620 | my $rel = shift; |
716b3d29 |
621 | return $self->search_related($rel)->find(@_); |
1a14aa3f |
622 | } |
623 | |
b3e1f1f5 |
624 | =head2 find_or_new_related |
625 | |
626 | my $new_obj = $obj->find_or_new_related('relname', \%col_data); |
627 | |
628 | Find an item of a related class. If none exists, instantiate a new item of the |
629 | related class. The object will not be saved into your storage until you call |
630 | L<DBIx::Class::Row/insert> on it. |
631 | |
632 | =cut |
633 | |
634 | sub find_or_new_related { |
635 | my $self = shift; |
e60dc79f |
636 | my $obj = $self->find_related(@_); |
637 | return defined $obj ? $obj : $self->new_related(@_); |
b3e1f1f5 |
638 | } |
639 | |
8091aa91 |
640 | =head2 find_or_create_related |
503536d5 |
641 | |
30236e47 |
642 | my $new_obj = $obj->find_or_create_related('relname', \%col_data); |
643 | |
27f01d1f |
644 | Find or create an item of a related class. See |
b3e1f1f5 |
645 | L<DBIx::Class::ResultSet/find_or_create> for details. |
503536d5 |
646 | |
647 | =cut |
648 | |
55e2d745 |
649 | sub find_or_create_related { |
650 | my $self = shift; |
9c2c91ea |
651 | my $obj = $self->find_related(@_); |
652 | return (defined($obj) ? $obj : $self->create_related(@_)); |
55e2d745 |
653 | } |
654 | |
045120e6 |
655 | =head2 update_or_create_related |
656 | |
657 | my $updated_item = $obj->update_or_create_related('relname', \%col_data, \%attrs?); |
658 | |
659 | Update or create an item of a related class. See |
f7e1846f |
660 | L<DBIx::Class::ResultSet/update_or_create> for details. |
045120e6 |
661 | |
662 | =cut |
663 | |
664 | sub update_or_create_related { |
665 | my $self = shift; |
666 | my $rel = shift; |
667 | return $self->related_resultset($rel)->update_or_create(@_); |
668 | } |
669 | |
8091aa91 |
670 | =head2 set_from_related |
503536d5 |
671 | |
30236e47 |
672 | $book->set_from_related('author', $author_obj); |
ac8e89d7 |
673 | $book->author($author_obj); ## same thing |
30236e47 |
674 | |
675 | Set column values on the current object, using related values from the given |
676 | related object. This is used to associate previously separate objects, for |
677 | example, to set the correct author for a book, find the Author object, then |
678 | call set_from_related on the book. |
679 | |
ac8e89d7 |
680 | This is called internally when you pass existing objects as values to |
48580715 |
681 | L<DBIx::Class::ResultSet/create>, or pass an object to a belongs_to accessor. |
ac8e89d7 |
682 | |
27f01d1f |
683 | The columns are only set in the local copy of the object, call L</update> to |
684 | set them in the storage. |
503536d5 |
685 | |
686 | =cut |
687 | |
55e2d745 |
688 | sub set_from_related { |
689 | my ($self, $rel, $f_obj) = @_; |
aa56106b |
690 | |
78b948c3 |
691 | my $rsrc = $self->result_source; |
692 | my $rel_info = $rsrc->relationship_info($rel) |
aa56106b |
693 | or $self->throw_exception( "No such relationship ${rel}" ); |
694 | |
2c037e6b |
695 | if (defined $f_obj) { |
164efde3 |
696 | my $f_class = $rel_info->{class}; |
2c037e6b |
697 | $self->throw_exception( "Object $f_obj isn't a ".$f_class ) |
6298a324 |
698 | unless blessed $f_obj and $f_obj->isa($f_class); |
2c037e6b |
699 | } |
a126983e |
700 | |
a126983e |
701 | |
78b948c3 |
702 | # FIXME - this is a bad position for this (also an identical copy in |
703 | # new_related), but I have no saner way to hook, and I absolutely |
704 | # want this to throw at least for coderefs, instead of the "insert a NULL |
705 | # when it gets hard" insanity --ribasushi |
706 | # |
707 | # sanity check - currently throw when a complex coderef rel is encountered |
708 | # FIXME - should THROW MOAR! |
709 | my ($cond, $crosstable, $relcols) = $rsrc->_resolve_condition ( |
710 | $rel_info->{cond}, $f_obj, $rel, $rel |
711 | ); |
712 | $self->throw_exception("Custom relationship '$rel' does not resolve to a join-free condition fragment") |
713 | if $crosstable; |
714 | $self->throw_exception(sprintf ( |
715 | "Custom relationship '%s' not definitive - returns conditions instead of values for column(s): %s", |
716 | $rel, |
717 | map { "'$_'" } @$relcols |
718 | )) if @{$relcols || []}; |
aa56106b |
719 | |
720 | $self->set_columns($cond); |
a126983e |
721 | |
55e2d745 |
722 | return 1; |
723 | } |
724 | |
8091aa91 |
725 | =head2 update_from_related |
503536d5 |
726 | |
30236e47 |
727 | $book->update_from_related('author', $author_obj); |
728 | |
27f01d1f |
729 | The same as L</"set_from_related">, but the changes are immediately updated |
730 | in storage. |
503536d5 |
731 | |
732 | =cut |
733 | |
55e2d745 |
734 | sub update_from_related { |
735 | my $self = shift; |
736 | $self->set_from_related(@_); |
737 | $self->update; |
738 | } |
739 | |
8091aa91 |
740 | =head2 delete_related |
503536d5 |
741 | |
30236e47 |
742 | $obj->delete_related('relname', $cond, $attrs); |
743 | |
744 | Delete any related item subject to the given conditions. |
503536d5 |
745 | |
746 | =cut |
747 | |
55e2d745 |
748 | sub delete_related { |
749 | my $self = shift; |
64acc2bc |
750 | my $obj = $self->search_related(@_)->delete; |
751 | delete $self->{related_resultsets}->{$_[0]}; |
752 | return $obj; |
55e2d745 |
753 | } |
754 | |
ec353f53 |
755 | =head2 add_to_$rel |
756 | |
757 | B<Currently only available for C<has_many>, C<many-to-many> and 'multi' type |
758 | relationships.> |
759 | |
760 | =over 4 |
761 | |
762 | =item Arguments: ($foreign_vals | $obj), $link_vals? |
763 | |
764 | =back |
765 | |
766 | my $role = $schema->resultset('Role')->find(1); |
767 | $actor->add_to_roles($role); |
768 | # creates a My::DBIC::Schema::ActorRoles linking table row object |
769 | |
770 | $actor->add_to_roles({ name => 'lead' }, { salary => 15_000_000 }); |
771 | # creates a new My::DBIC::Schema::Role row object and the linking table |
772 | # object with an extra column in the link |
773 | |
774 | Adds a linking table object for C<$obj> or C<$foreign_vals>. If the first |
775 | argument is a hash reference, the related object is created first with the |
776 | column values in the hash. If an object reference is given, just the linking |
777 | table object is created. In either case, any additional column values for the |
778 | linking table object can be specified in C<$link_vals>. |
779 | |
780 | =head2 set_$rel |
781 | |
782 | B<Currently only available for C<many-to-many> relationships.> |
783 | |
784 | =over 4 |
785 | |
ac36a402 |
786 | =item Arguments: (\@hashrefs | \@objs), $link_vals? |
ec353f53 |
787 | |
788 | =back |
789 | |
790 | my $actor = $schema->resultset('Actor')->find(1); |
fd323bf1 |
791 | my @roles = $schema->resultset('Role')->search({ role => |
debccec3 |
792 | { '-in' => ['Fred', 'Barney'] } } ); |
ec353f53 |
793 | |
4d3a827d |
794 | $actor->set_roles(\@roles); |
795 | # Replaces all of $actor's previous roles with the two named |
ec353f53 |
796 | |
ac36a402 |
797 | $actor->set_roles(\@roles, { salary => 15_000_000 }); |
798 | # Sets a column in the link table for all roles |
799 | |
800 | |
4d3a827d |
801 | Replace all the related objects with the given reference to a list of |
802 | objects. This does a C<delete> B<on the link table resultset> to remove the |
803 | association between the current object and all related objects, then calls |
804 | C<add_to_$rel> repeatedly to link all the new objects. |
bba68c67 |
805 | |
806 | Note that this means that this method will B<not> delete any objects in the |
807 | table on the right side of the relation, merely that it will delete the link |
808 | between them. |
ec353f53 |
809 | |
4d3a827d |
810 | Due to a mistake in the original implementation of this method, it will also |
811 | accept a list of objects or hash references. This is B<deprecated> and will be |
812 | removed in a future version. |
813 | |
ec353f53 |
814 | =head2 remove_from_$rel |
815 | |
816 | B<Currently only available for C<many-to-many> relationships.> |
817 | |
818 | =over 4 |
819 | |
820 | =item Arguments: $obj |
821 | |
822 | =back |
823 | |
824 | my $role = $schema->resultset('Role')->find(1); |
825 | $actor->remove_from_roles($role); |
826 | # removes $role's My::DBIC::Schema::ActorRoles linking table row object |
827 | |
828 | Removes the link between the current object and the related object. Note that |
829 | the related object itself won't be deleted unless you call ->delete() on |
830 | it. This method just removes the link between the two objects. |
831 | |
55e2d745 |
832 | =head1 AUTHORS |
833 | |
daec44b8 |
834 | Matt S. Trout <mst@shadowcatsystems.co.uk> |
55e2d745 |
835 | |
836 | =head1 LICENSE |
837 | |
838 | You may distribute this code under the same terms as Perl itself. |
839 | |
840 | =cut |
841 | |
4d87db01 |
842 | 1; |