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89c0a5a2 |
1 | package DBIx::Class::ResultSet; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | use overload |
6 | '0+' => 'count', |
a910dc57 |
7 | 'bool' => sub { 1; }, |
89c0a5a2 |
8 | fallback => 1; |
3c5b25c5 |
9 | use Data::Page; |
ea20d0fd |
10 | use Storable; |
89c0a5a2 |
11 | |
701da8c4 |
12 | use base qw/DBIx::Class/; |
13 | __PACKAGE__->load_components(qw/AccessorGroup/); |
14 | __PACKAGE__->mk_group_accessors('simple' => 'result_source'); |
15 | |
ee38fa40 |
16 | =head1 NAME |
17 | |
bfab575a |
18 | DBIx::Class::ResultSet - Responsible for fetching and creating resultset. |
ee38fa40 |
19 | |
bfab575a |
20 | =head1 SYNOPSIS |
ee38fa40 |
21 | |
a33df5d4 |
22 | my $rs = $schema->resultset('User')->search(registered => 1); |
23 | my @rows = $schema->resultset('Foo')->search(bar => 'baz'); |
ee38fa40 |
24 | |
25 | =head1 DESCRIPTION |
26 | |
bfab575a |
27 | The resultset is also known as an iterator. It is responsible for handling |
a33df5d4 |
28 | queries that may return an arbitrary number of rows, e.g. via L</search> |
bfab575a |
29 | or a C<has_many> relationship. |
ee38fa40 |
30 | |
a33df5d4 |
31 | In the examples below, the following table classes are used: |
32 | |
33 | package MyApp::Schema::Artist; |
34 | use base qw/DBIx::Class/; |
35 | __PACKAGE__->table('artist'); |
36 | __PACKAGE__->add_columns(qw/artistid name/); |
37 | __PACKAGE__->set_primary_key('artistid'); |
38 | __PACKAGE__->has_many(cds => 'MyApp::Schema::CD'); |
39 | 1; |
40 | |
41 | package MyApp::Schema::CD; |
42 | use base qw/DBIx::Class/; |
43 | __PACKAGE__->table('artist'); |
44 | __PACKAGE__->add_columns(qw/cdid artist title year/); |
45 | __PACKAGE__->set_primary_key('cdid'); |
46 | __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist'); |
47 | 1; |
48 | |
ee38fa40 |
49 | =head1 METHODS |
50 | |
87c4e602 |
51 | =head2 new |
52 | |
53 | =head3 Arguments: ($source, \%$attrs) |
ee38fa40 |
54 | |
a33df5d4 |
55 | The resultset constructor. Takes a source object (usually a |
80c90f5d |
56 | L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see L</ATRRIBUTES> |
a33df5d4 |
57 | below). Does not perform any queries -- these are executed as needed by the |
58 | other methods. |
59 | |
60 | Generally you won't need to construct a resultset manually. You'll |
61 | automatically get one from e.g. a L</search> called in scalar context: |
62 | |
63 | my $rs = $schema->resultset('CD')->search({ title => '100th Window' }); |
ee38fa40 |
64 | |
65 | =cut |
66 | |
89c0a5a2 |
67 | sub new { |
fea3d045 |
68 | my $class = shift; |
f9db5527 |
69 | return $class->new_result(@_) if ref $class; |
fea3d045 |
70 | my ($source, $attrs) = @_; |
b98e75f6 |
71 | #use Data::Dumper; warn Dumper($attrs); |
ea20d0fd |
72 | $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } }; |
c7ce65e6 |
73 | my %seen; |
6aeb9185 |
74 | my $alias = ($attrs->{alias} ||= 'me'); |
a9433341 |
75 | if ($attrs->{cols} || !$attrs->{select}) { |
76 | delete $attrs->{as} if $attrs->{cols}; |
976f3686 |
77 | my @cols = ($attrs->{cols} |
78 | ? @{delete $attrs->{cols}} |
a9433341 |
79 | : $source->columns); |
6aeb9185 |
80 | $attrs->{select} = [ map { m/\./ ? $_ : "${alias}.$_" } @cols ]; |
976f3686 |
81 | } |
6aeb9185 |
82 | $attrs->{as} ||= [ map { m/^$alias\.(.*)$/ ? $1 : $_ } @{$attrs->{select}} ]; |
5ac6a044 |
83 | if (my $include = delete $attrs->{include_columns}) { |
84 | push(@{$attrs->{select}}, @$include); |
85 | push(@{$attrs->{as}}, map { m/([^\.]+)$/; $1; } @$include); |
86 | } |
976f3686 |
87 | #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/}); |
fea3d045 |
88 | $attrs->{from} ||= [ { $alias => $source->from } ]; |
8fab5eef |
89 | $attrs->{seen_join} ||= {}; |
b52e9bf8 |
90 | if (my $join = delete $attrs->{join}) { |
91 | foreach my $j (ref $join eq 'ARRAY' |
92 | ? (@{$join}) : ($join)) { |
c7ce65e6 |
93 | if (ref $j eq 'HASH') { |
94 | $seen{$_} = 1 foreach keys %$j; |
95 | } else { |
96 | $seen{$j} = 1; |
97 | } |
98 | } |
8fab5eef |
99 | push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join})); |
c7ce65e6 |
100 | } |
54540863 |
101 | $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct}; |
b3e8ac9b |
102 | |
103 | if (my $prefetch = delete $attrs->{prefetch}) { |
104 | foreach my $p (ref $prefetch eq 'ARRAY' |
105 | ? (@{$prefetch}) : ($prefetch)) { |
106 | if( ref $p eq 'HASH' ) { |
107 | foreach my $key (keys %$p) { |
108 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
109 | unless $seen{$key}; |
110 | } |
111 | } |
112 | else { |
113 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
114 | unless $seen{$p}; |
115 | } |
489709af |
116 | my @prefetch = $source->resolve_prefetch($p, $attrs->{alias}); |
b3e8ac9b |
117 | #die Dumper \@cols; |
489709af |
118 | push(@{$attrs->{select}}, map { $_->[0] } @prefetch); |
119 | push(@{$attrs->{as}}, map { $_->[1] } @prefetch); |
b3e8ac9b |
120 | } |
fef5d100 |
121 | } |
b3e8ac9b |
122 | |
6aeb9185 |
123 | if ($attrs->{page}) { |
124 | $attrs->{rows} ||= 10; |
125 | $attrs->{offset} ||= 0; |
126 | $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1)); |
127 | } |
89c0a5a2 |
128 | my $new = { |
701da8c4 |
129 | result_source => $source, |
89c0a5a2 |
130 | cond => $attrs->{where}, |
0a3c5b43 |
131 | from => $attrs->{from}, |
3c5b25c5 |
132 | count => undef, |
93b004d3 |
133 | page => delete $attrs->{page}, |
3c5b25c5 |
134 | pager => undef, |
89c0a5a2 |
135 | attrs => $attrs }; |
2f5911b2 |
136 | bless ($new, $class); |
9229f20a |
137 | return $new; |
89c0a5a2 |
138 | } |
139 | |
bfab575a |
140 | =head2 search |
0a3c5b43 |
141 | |
87f0da6a |
142 | my @obj = $rs->search({ foo => 3 }); # "... WHERE foo = 3" |
143 | my $new_rs = $rs->search({ foo => 3 }); |
144 | |
6009260a |
145 | If you need to pass in additional attributes but no additional condition, |
a33df5d4 |
146 | call it as C<search({}, \%attrs);>. |
87f0da6a |
147 | |
a33df5d4 |
148 | # "SELECT foo, bar FROM $class_table" |
149 | my @all = $class->search({}, { cols => [qw/foo bar/] }); |
0a3c5b43 |
150 | |
151 | =cut |
152 | |
153 | sub search { |
154 | my $self = shift; |
155 | |
6009260a |
156 | #use Data::Dumper;warn Dumper(@_); |
ff7bb7a1 |
157 | my $rs; |
158 | if( @_ ) { |
159 | |
160 | my $attrs = { %{$self->{attrs}} }; |
161 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
162 | $attrs = { %$attrs, %{ pop(@_) } }; |
163 | } |
6009260a |
164 | |
ff7bb7a1 |
165 | my $where = (@_ ? ((@_ == 1 || ref $_[0] eq "HASH") ? shift : {@_}) : undef()); |
166 | if (defined $where) { |
167 | $where = (defined $attrs->{where} |
ad3d2d7c |
168 | ? { '-and' => |
169 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
170 | $where, $attrs->{where} ] } |
0a3c5b43 |
171 | : $where); |
ff7bb7a1 |
172 | $attrs->{where} = $where; |
173 | } |
0a3c5b43 |
174 | |
ff7bb7a1 |
175 | $rs = (ref $self)->new($self->result_source, $attrs); |
176 | } |
177 | else { |
178 | $rs = $self; |
179 | $rs->reset(); |
180 | } |
0a3c5b43 |
181 | return (wantarray ? $rs->all : $rs); |
182 | } |
183 | |
87f0da6a |
184 | =head2 search_literal |
185 | |
6009260a |
186 | my @obj = $rs->search_literal($literal_where_cond, @bind); |
187 | my $new_rs = $rs->search_literal($literal_where_cond, @bind); |
188 | |
189 | Pass a literal chunk of SQL to be added to the conditional part of the |
87f0da6a |
190 | resultset. |
6009260a |
191 | |
bfab575a |
192 | =cut |
193 | |
6009260a |
194 | sub search_literal { |
195 | my ($self, $cond, @vals) = @_; |
196 | my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {}); |
197 | $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ]; |
198 | return $self->search(\$cond, $attrs); |
199 | } |
0a3c5b43 |
200 | |
87c4e602 |
201 | =head2 find |
202 | |
203 | =head3 Arguments: (@colvalues) | (\%cols, \%attrs?) |
87f0da6a |
204 | |
205 | Finds a row based on its primary key or unique constraint. For example: |
206 | |
87f0da6a |
207 | my $cd = $schema->resultset('CD')->find(5); |
208 | |
209 | Also takes an optional C<key> attribute, to search by a specific key or unique |
210 | constraint. For example: |
211 | |
212 | my $cd = $schema->resultset('CD')->find_or_create( |
213 | { |
214 | artist => 'Massive Attack', |
215 | title => 'Mezzanine', |
216 | }, |
217 | { key => 'artist_title' } |
218 | ); |
219 | |
a33df5d4 |
220 | See also L</find_or_create> and L</update_or_create>. |
221 | |
87f0da6a |
222 | =cut |
716b3d29 |
223 | |
224 | sub find { |
225 | my ($self, @vals) = @_; |
226 | my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {}); |
87f0da6a |
227 | |
701da8c4 |
228 | my @cols = $self->result_source->primary_columns; |
87f0da6a |
229 | if (exists $attrs->{key}) { |
701da8c4 |
230 | my %uniq = $self->result_source->unique_constraints; |
87f0da6a |
231 | $self->( "Unknown key " . $attrs->{key} . " on " . $self->name ) |
232 | unless exists $uniq{$attrs->{key}}; |
233 | @cols = @{ $uniq{$attrs->{key}} }; |
234 | } |
235 | #use Data::Dumper; warn Dumper($attrs, @vals, @cols); |
701da8c4 |
236 | $self->throw_exception( "Can't find unless a primary key or unique constraint is defined" ) |
87f0da6a |
237 | unless @cols; |
238 | |
716b3d29 |
239 | my $query; |
240 | if (ref $vals[0] eq 'HASH') { |
01bc091e |
241 | $query = { %{$vals[0]} }; |
87f0da6a |
242 | } elsif (@cols == @vals) { |
716b3d29 |
243 | $query = {}; |
87f0da6a |
244 | @{$query}{@cols} = @vals; |
716b3d29 |
245 | } else { |
246 | $query = {@vals}; |
247 | } |
01bc091e |
248 | foreach (keys %$query) { |
249 | next if m/\./; |
250 | $query->{$self->{attrs}{alias}.'.'.$_} = delete $query->{$_}; |
251 | } |
716b3d29 |
252 | #warn Dumper($query); |
a04ab285 |
253 | return (keys %$attrs |
254 | ? $self->search($query,$attrs)->single |
255 | : $self->single($query)); |
716b3d29 |
256 | } |
257 | |
b52e9bf8 |
258 | =head2 search_related |
259 | |
260 | $rs->search_related('relname', $cond?, $attrs?); |
261 | |
a33df5d4 |
262 | Search the specified relationship. Optionally specify a condition for matching |
263 | records. |
264 | |
b52e9bf8 |
265 | =cut |
266 | |
6aeb9185 |
267 | sub search_related { |
64acc2bc |
268 | return shift->related_resultset(shift)->search(@_); |
6aeb9185 |
269 | } |
b52e9bf8 |
270 | |
bfab575a |
271 | =head2 cursor |
ee38fa40 |
272 | |
bfab575a |
273 | Returns a storage-driven cursor to the given resultset. |
ee38fa40 |
274 | |
275 | =cut |
276 | |
73f58123 |
277 | sub cursor { |
278 | my ($self) = @_; |
701da8c4 |
279 | my ($attrs) = $self->{attrs}; |
6aeb9185 |
280 | $attrs = { %$attrs }; |
73f58123 |
281 | return $self->{cursor} |
701da8c4 |
282 | ||= $self->result_source->storage->select($self->{from}, $attrs->{select}, |
73f58123 |
283 | $attrs->{where},$attrs); |
284 | } |
285 | |
a04ab285 |
286 | =head2 single |
287 | |
288 | Inflates the first result without creating a cursor |
289 | |
290 | =cut |
291 | |
292 | sub single { |
293 | my ($self, $extra) = @_; |
294 | my ($attrs) = $self->{attrs}; |
295 | $attrs = { %$attrs }; |
296 | if ($extra) { |
297 | if (defined $attrs->{where}) { |
298 | $attrs->{where} = { |
299 | '-and' |
300 | => [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
301 | delete $attrs->{where}, $extra ] |
302 | }; |
303 | } else { |
304 | $attrs->{where} = $extra; |
305 | } |
306 | } |
307 | my @data = $self->result_source->storage->select_single( |
308 | $self->{from}, $attrs->{select}, |
309 | $attrs->{where},$attrs); |
310 | return (@data ? $self->_construct_object(@data) : ()); |
311 | } |
312 | |
313 | |
87f0da6a |
314 | =head2 search_like |
315 | |
a33df5d4 |
316 | Perform a search, but use C<LIKE> instead of equality as the condition. Note |
317 | that this is simply a convenience method; you most likely want to use |
318 | L</search> with specific operators. |
319 | |
320 | For more information, see L<DBIx::Class::Manual::Cookbook>. |
87f0da6a |
321 | |
322 | =cut |
58a4bd18 |
323 | |
324 | sub search_like { |
325 | my $class = shift; |
326 | my $attrs = { }; |
327 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
328 | $attrs = pop(@_); |
329 | } |
330 | my $query = ref $_[0] eq "HASH" ? { %{shift()} }: {@_}; |
331 | $query->{$_} = { 'like' => $query->{$_} } for keys %$query; |
332 | return $class->search($query, { %$attrs }); |
333 | } |
334 | |
87c4e602 |
335 | =head2 slice |
336 | |
337 | =head3 Arguments: ($first, $last) |
ee38fa40 |
338 | |
bfab575a |
339 | Returns a subset of elements from the resultset. |
ee38fa40 |
340 | |
341 | =cut |
342 | |
89c0a5a2 |
343 | sub slice { |
344 | my ($self, $min, $max) = @_; |
345 | my $attrs = { %{ $self->{attrs} || {} } }; |
6aeb9185 |
346 | $attrs->{offset} ||= 0; |
347 | $attrs->{offset} += $min; |
89c0a5a2 |
348 | $attrs->{rows} = ($max ? ($max - $min + 1) : 1); |
701da8c4 |
349 | my $slice = (ref $self)->new($self->result_source, $attrs); |
89c0a5a2 |
350 | return (wantarray ? $slice->all : $slice); |
351 | } |
352 | |
87f0da6a |
353 | =head2 next |
ee38fa40 |
354 | |
a33df5d4 |
355 | Returns the next element in the resultset (C<undef> is there is none). |
356 | |
357 | Can be used to efficiently iterate over records in the resultset: |
358 | |
359 | my $rs = $schema->resultset('CD')->search({}); |
360 | while (my $cd = $rs->next) { |
361 | print $cd->title; |
362 | } |
ee38fa40 |
363 | |
364 | =cut |
365 | |
89c0a5a2 |
366 | sub next { |
367 | my ($self) = @_; |
64acc2bc |
368 | my $cache = $self->get_cache; |
369 | if( @$cache ) { |
370 | $self->{all_cache_position} ||= 0; |
371 | my $obj = $cache->[$self->{all_cache_position}]; |
372 | $self->{all_cache_position}++; |
373 | return $obj; |
374 | } |
73f58123 |
375 | my @row = $self->cursor->next; |
a953d8d9 |
376 | # warn Dumper(\@row); use Data::Dumper; |
89c0a5a2 |
377 | return unless (@row); |
c7ce65e6 |
378 | return $self->_construct_object(@row); |
379 | } |
380 | |
381 | sub _construct_object { |
382 | my ($self, @row) = @_; |
64acc2bc |
383 | my @row_orig = @row; # copy @row for key comparison later, because @row will change |
b3e8ac9b |
384 | my @as = @{ $self->{attrs}{as} }; |
f9cc31dd |
385 | #use Data::Dumper; warn Dumper \@as; |
976f3686 |
386 | #warn "@cols -> @row"; |
b3e8ac9b |
387 | my $info = [ {}, {} ]; |
388 | foreach my $as (@as) { |
64acc2bc |
389 | my $rs = $self; |
b3e8ac9b |
390 | my $target = $info; |
391 | my @parts = split(/\./, $as); |
392 | my $col = pop(@parts); |
393 | foreach my $p (@parts) { |
394 | $target = $target->[1]->{$p} ||= []; |
64acc2bc |
395 | |
f9cc31dd |
396 | $rs = $rs->related_resultset($p) if $rs->{attrs}->{cache}; |
c7ce65e6 |
397 | } |
f9cc31dd |
398 | |
64acc2bc |
399 | $target->[0]->{$col} = shift @row |
400 | if ref($target->[0]) ne 'ARRAY'; # arrayref is pre-inflated objects, do not overwrite |
c7ce65e6 |
401 | } |
b3e8ac9b |
402 | #use Data::Dumper; warn Dumper(\@as, $info); |
701da8c4 |
403 | my $new = $self->result_source->result_class->inflate_result( |
404 | $self->result_source, @$info); |
33ce49d6 |
405 | $new = $self->{attrs}{record_filter}->($new) |
406 | if exists $self->{attrs}{record_filter}; |
f9cc31dd |
407 | |
408 | if( $self->{attrs}->{cache} ) { |
409 | while( my( $rel, $rs ) = each( %{$self->{related_resultsets}} ) ) { |
410 | $rs->all; |
411 | #warn "$rel:", @{$rs->get_cache}; |
412 | } |
413 | $self->build_rr( $self, $new ); |
414 | } |
415 | |
33ce49d6 |
416 | return $new; |
89c0a5a2 |
417 | } |
f9cc31dd |
418 | |
419 | sub build_rr { |
420 | # build related resultsets for supplied object |
421 | my ( $self, $context, $obj ) = @_; |
422 | |
423 | my $re = qr/^\w+\./; |
424 | while( my ($rel, $rs) = each( %{$context->{related_resultsets}} ) ) { |
425 | #warn "context:", $context->result_source->name, ", rel:$rel, rs:", $rs->result_source->name; |
426 | my @objs = (); |
427 | my $map = {}; |
428 | my $cond = $context->result_source->relationship_info($rel)->{cond}; |
429 | keys %$cond; |
430 | while( my( $rel_key, $pk ) = each(%$cond) ) { |
431 | $rel_key =~ s/$re//; |
432 | $pk =~ s/$re//; |
433 | $map->{$rel_key} = $pk; |
434 | } |
435 | |
436 | $rs->reset(); |
437 | while( my $rel_obj = $rs->next ) { |
438 | while( my( $rel_key, $pk ) = each(%$map) ) { |
439 | if( $rel_obj->get_column($rel_key) eq $obj->get_column($pk) ) { |
440 | push @objs, $rel_obj; |
441 | } |
442 | } |
443 | } |
444 | |
445 | my $rel_rs = $obj->related_resultset($rel); |
446 | $rel_rs->{attrs}->{cache} = 1; |
447 | $rel_rs->set_cache( \@objs ); |
448 | |
449 | while( my $rel_obj = $rel_rs->next ) { |
450 | $self->build_rr( $rs, $rel_obj ); |
451 | } |
452 | |
453 | } |
454 | |
455 | } |
89c0a5a2 |
456 | |
87c4e602 |
457 | =head2 result_source |
701da8c4 |
458 | |
459 | Returns a reference to the result source for this recordset. |
460 | |
461 | =cut |
462 | |
463 | |
bfab575a |
464 | =head2 count |
ee38fa40 |
465 | |
bfab575a |
466 | Performs an SQL C<COUNT> with the same query as the resultset was built |
6009260a |
467 | with to find the number of elements. If passed arguments, does a search |
468 | on the resultset and counts the results of that. |
ee38fa40 |
469 | |
bda4c2b8 |
470 | Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY> |
471 | using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do |
472 | not support C<DISTINCT> with multiple columns. If you are using such a |
473 | database, you should only use columns from the main table in your C<group_by> |
474 | clause. |
475 | |
ee38fa40 |
476 | =cut |
477 | |
89c0a5a2 |
478 | sub count { |
6009260a |
479 | my $self = shift; |
480 | return $self->search(@_)->count if @_ && defined $_[0]; |
6aeb9185 |
481 | unless (defined $self->{count}) { |
64acc2bc |
482 | return scalar @{ $self->get_cache } |
483 | if @{ $self->get_cache }; |
15c382be |
484 | my $group_by; |
485 | my $select = { 'count' => '*' }; |
486 | if( $group_by = delete $self->{attrs}{group_by} ) { |
dec2517f |
487 | my @distinct = (ref $group_by ? @$group_by : ($group_by)); |
15c382be |
488 | # todo: try CONCAT for multi-column pk |
489 | my @pk = $self->result_source->primary_columns; |
490 | if( scalar(@pk) == 1 ) { |
491 | my $pk = shift(@pk); |
492 | my $alias = $self->{attrs}{alias}; |
493 | my $re = qr/^($alias\.)?$pk$/; |
d0f1e63f |
494 | foreach my $column ( @distinct) { |
15c382be |
495 | if( $column =~ $re ) { |
496 | @distinct = ( $column ); |
497 | last; |
498 | } |
499 | } |
500 | } |
501 | |
502 | $select = { count => { 'distinct' => \@distinct } }; |
503 | #use Data::Dumper; die Dumper $select; |
504 | } |
505 | |
976f3686 |
506 | my $attrs = { %{ $self->{attrs} }, |
15c382be |
507 | select => $select, |
54540863 |
508 | as => [ 'count' ] }; |
ea20d0fd |
509 | # offset, order by and page are not needed to count. record_filter is cdbi |
510 | delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/; |
3c5b25c5 |
511 | |
701da8c4 |
512 | ($self->{count}) = (ref $self)->new($self->result_source, $attrs)->cursor->next; |
15c382be |
513 | $self->{attrs}{group_by} = $group_by; |
3c5b25c5 |
514 | } |
515 | return 0 unless $self->{count}; |
6aeb9185 |
516 | my $count = $self->{count}; |
517 | $count -= $self->{attrs}{offset} if $self->{attrs}{offset}; |
518 | $count = $self->{attrs}{rows} if |
519 | ($self->{attrs}{rows} && $self->{attrs}{rows} < $count); |
520 | return $count; |
89c0a5a2 |
521 | } |
522 | |
bfab575a |
523 | =head2 count_literal |
6009260a |
524 | |
a33df5d4 |
525 | Calls L</search_literal> with the passed arguments, then L</count>. |
6009260a |
526 | |
527 | =cut |
528 | |
529 | sub count_literal { shift->search_literal(@_)->count; } |
530 | |
bfab575a |
531 | =head2 all |
ee38fa40 |
532 | |
bfab575a |
533 | Returns all elements in the resultset. Called implictly if the resultset |
534 | is returned in list context. |
ee38fa40 |
535 | |
536 | =cut |
537 | |
89c0a5a2 |
538 | sub all { |
539 | my ($self) = @_; |
64acc2bc |
540 | return @{ $self->get_cache } |
541 | if @{ $self->get_cache }; |
542 | if( $self->{attrs}->{cache} ) { |
543 | my @obj = map { $self->_construct_object(@$_); } |
544 | $self->cursor->all; |
545 | $self->set_cache( \@obj ); |
546 | return @{ $self->get_cache }; |
547 | } |
c7ce65e6 |
548 | return map { $self->_construct_object(@$_); } |
73f58123 |
549 | $self->cursor->all; |
89c0a5a2 |
550 | } |
551 | |
bfab575a |
552 | =head2 reset |
ee38fa40 |
553 | |
bfab575a |
554 | Resets the resultset's cursor, so you can iterate through the elements again. |
ee38fa40 |
555 | |
556 | =cut |
557 | |
89c0a5a2 |
558 | sub reset { |
559 | my ($self) = @_; |
64acc2bc |
560 | $self->{all_cache_position} = 0; |
73f58123 |
561 | $self->cursor->reset; |
89c0a5a2 |
562 | return $self; |
563 | } |
564 | |
bfab575a |
565 | =head2 first |
ee38fa40 |
566 | |
bfab575a |
567 | Resets the resultset and returns the first element. |
ee38fa40 |
568 | |
569 | =cut |
570 | |
89c0a5a2 |
571 | sub first { |
572 | return $_[0]->reset->next; |
573 | } |
574 | |
87c4e602 |
575 | =head2 update |
576 | |
577 | =head3 Arguments: (\%values) |
c01ab172 |
578 | |
a33df5d4 |
579 | Sets the specified columns in the resultset to the supplied values. |
c01ab172 |
580 | |
581 | =cut |
582 | |
583 | sub update { |
584 | my ($self, $values) = @_; |
701da8c4 |
585 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
586 | return $self->result_source->storage->update( |
587 | $self->result_source->from, $values, $self->{cond}); |
c01ab172 |
588 | } |
589 | |
87c4e602 |
590 | =head2 update_all |
591 | |
592 | =head3 Arguments: (\%values) |
c01ab172 |
593 | |
a33df5d4 |
594 | Fetches all objects and updates them one at a time. Note that C<update_all> |
595 | will run cascade triggers while L</update> will not. |
c01ab172 |
596 | |
597 | =cut |
598 | |
599 | sub update_all { |
600 | my ($self, $values) = @_; |
701da8c4 |
601 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
c01ab172 |
602 | foreach my $obj ($self->all) { |
603 | $obj->set_columns($values)->update; |
604 | } |
605 | return 1; |
606 | } |
607 | |
bfab575a |
608 | =head2 delete |
ee38fa40 |
609 | |
c01ab172 |
610 | Deletes the contents of the resultset from its result source. |
ee38fa40 |
611 | |
612 | =cut |
613 | |
28927b50 |
614 | sub delete { |
89c0a5a2 |
615 | my ($self) = @_; |
ca4b5ab7 |
616 | my $del = {}; |
617 | $self->throw_exception("Can't delete on resultset with condition unless hash or array") |
618 | unless (ref($self->{cond}) eq 'HASH' || ref($self->{cond}) eq 'ARRAY'); |
619 | if (ref $self->{cond} eq 'ARRAY') { |
620 | $del = [ map { my %hash; |
621 | foreach my $key (keys %{$_}) { |
622 | $key =~ /([^\.]+)$/; |
623 | $hash{$1} = $_->{$key}; |
624 | }; \%hash; } @{$self->{cond}} ]; |
625 | } elsif ((keys %{$self->{cond}})[0] eq '-and') { |
626 | $del->{-and} = [ map { my %hash; |
627 | foreach my $key (keys %{$_}) { |
628 | $key =~ /([^\.]+)$/; |
629 | $hash{$1} = $_->{$key}; |
630 | }; \%hash; } @{$self->{cond}{-and}} ]; |
631 | } else { |
632 | foreach my $key (keys %{$self->{cond}}) { |
633 | $key =~ /([^\.]+)$/; |
634 | $del->{$1} = $self->{cond}{$key}; |
635 | } |
636 | } |
637 | $self->result_source->storage->delete($self->result_source->from, $del); |
89c0a5a2 |
638 | return 1; |
639 | } |
640 | |
c01ab172 |
641 | =head2 delete_all |
642 | |
a33df5d4 |
643 | Fetches all objects and deletes them one at a time. Note that C<delete_all> |
644 | will run cascade triggers while L</delete> will not. |
c01ab172 |
645 | |
646 | =cut |
647 | |
648 | sub delete_all { |
649 | my ($self) = @_; |
650 | $_->delete for $self->all; |
651 | return 1; |
652 | } |
28927b50 |
653 | |
bfab575a |
654 | =head2 pager |
ee38fa40 |
655 | |
656 | Returns a L<Data::Page> object for the current resultset. Only makes |
a33df5d4 |
657 | sense for queries with a C<page> attribute. |
ee38fa40 |
658 | |
659 | =cut |
660 | |
3c5b25c5 |
661 | sub pager { |
662 | my ($self) = @_; |
663 | my $attrs = $self->{attrs}; |
701da8c4 |
664 | $self->throw_exception("Can't create pager for non-paged rs") unless $self->{page}; |
6aeb9185 |
665 | $attrs->{rows} ||= 10; |
666 | $self->count; |
667 | return $self->{pager} ||= Data::Page->new( |
93b004d3 |
668 | $self->{count}, $attrs->{rows}, $self->{page}); |
3c5b25c5 |
669 | } |
670 | |
87c4e602 |
671 | =head2 page |
672 | |
673 | =head3 Arguments: ($page_num) |
ee38fa40 |
674 | |
bfab575a |
675 | Returns a new resultset for the specified page. |
ee38fa40 |
676 | |
677 | =cut |
678 | |
3c5b25c5 |
679 | sub page { |
680 | my ($self, $page) = @_; |
6aeb9185 |
681 | my $attrs = { %{$self->{attrs}} }; |
3c5b25c5 |
682 | $attrs->{page} = $page; |
701da8c4 |
683 | return (ref $self)->new($self->result_source, $attrs); |
fea3d045 |
684 | } |
685 | |
87c4e602 |
686 | =head2 new_result |
687 | |
688 | =head3 Arguments: (\%vals) |
fea3d045 |
689 | |
87f0da6a |
690 | Creates a result in the resultset's result class. |
fea3d045 |
691 | |
692 | =cut |
693 | |
694 | sub new_result { |
695 | my ($self, $values) = @_; |
701da8c4 |
696 | $self->throw_exception( "new_result needs a hash" ) |
fea3d045 |
697 | unless (ref $values eq 'HASH'); |
701da8c4 |
698 | $self->throw_exception( "Can't abstract implicit construct, condition not a hash" ) |
fea3d045 |
699 | if ($self->{cond} && !(ref $self->{cond} eq 'HASH')); |
700 | my %new = %$values; |
701 | my $alias = $self->{attrs}{alias}; |
702 | foreach my $key (keys %{$self->{cond}||{}}) { |
703 | $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:$alias\.)?([^\.]+)$/); |
704 | } |
701da8c4 |
705 | my $obj = $self->result_source->result_class->new(\%new); |
706 | $obj->result_source($self->result_source) if $obj->can('result_source'); |
097d3227 |
707 | $obj; |
fea3d045 |
708 | } |
709 | |
87c4e602 |
710 | =head2 create |
711 | |
712 | =head3 Arguments: (\%vals) |
fea3d045 |
713 | |
87f0da6a |
714 | Inserts a record into the resultset and returns the object. |
fea3d045 |
715 | |
a33df5d4 |
716 | Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. |
fea3d045 |
717 | |
718 | =cut |
719 | |
720 | sub create { |
721 | my ($self, $attrs) = @_; |
701da8c4 |
722 | $self->throw_exception( "create needs a hashref" ) unless ref $attrs eq 'HASH'; |
fea3d045 |
723 | return $self->new_result($attrs)->insert; |
3c5b25c5 |
724 | } |
725 | |
87c4e602 |
726 | =head2 find_or_create |
727 | |
728 | =head3 Arguments: (\%vals, \%attrs?) |
87f0da6a |
729 | |
730 | $class->find_or_create({ key => $val, ... }); |
c2b15ecc |
731 | |
c2b15ecc |
732 | Searches for a record matching the search condition; if it doesn't find one, |
cf7b40ed |
733 | creates one and returns that instead. |
87f0da6a |
734 | |
87f0da6a |
735 | my $cd = $schema->resultset('CD')->find_or_create({ |
736 | cdid => 5, |
737 | artist => 'Massive Attack', |
738 | title => 'Mezzanine', |
739 | year => 2005, |
740 | }); |
741 | |
742 | Also takes an optional C<key> attribute, to search by a specific key or unique |
743 | constraint. For example: |
744 | |
745 | my $cd = $schema->resultset('CD')->find_or_create( |
746 | { |
747 | artist => 'Massive Attack', |
748 | title => 'Mezzanine', |
749 | }, |
750 | { key => 'artist_title' } |
751 | ); |
752 | |
753 | See also L</find> and L</update_or_create>. |
754 | |
c2b15ecc |
755 | =cut |
756 | |
757 | sub find_or_create { |
758 | my $self = shift; |
87f0da6a |
759 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
760 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
761 | my $exists = $self->find($hash, $attrs); |
c2b15ecc |
762 | return defined($exists) ? $exists : $self->create($hash); |
763 | } |
764 | |
87f0da6a |
765 | =head2 update_or_create |
766 | |
767 | $class->update_or_create({ key => $val, ... }); |
768 | |
769 | First, search for an existing row matching one of the unique constraints |
770 | (including the primary key) on the source of this resultset. If a row is |
771 | found, update it with the other given column values. Otherwise, create a new |
772 | row. |
773 | |
774 | Takes an optional C<key> attribute to search on a specific unique constraint. |
775 | For example: |
776 | |
777 | # In your application |
778 | my $cd = $schema->resultset('CD')->update_or_create( |
779 | { |
780 | artist => 'Massive Attack', |
781 | title => 'Mezzanine', |
782 | year => 1998, |
783 | }, |
784 | { key => 'artist_title' } |
785 | ); |
786 | |
787 | If no C<key> is specified, it searches on all unique constraints defined on the |
788 | source, including the primary key. |
789 | |
790 | If the C<key> is specified as C<primary>, search only on the primary key. |
791 | |
a33df5d4 |
792 | See also L</find> and L</find_or_create>. |
793 | |
87f0da6a |
794 | =cut |
795 | |
796 | sub update_or_create { |
797 | my $self = shift; |
798 | |
799 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
800 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
801 | |
701da8c4 |
802 | my %unique_constraints = $self->result_source->unique_constraints; |
87f0da6a |
803 | my @constraint_names = (exists $attrs->{key} |
804 | ? ($attrs->{key}) |
805 | : keys %unique_constraints); |
806 | |
807 | my @unique_hashes; |
808 | foreach my $name (@constraint_names) { |
809 | my @unique_cols = @{ $unique_constraints{$name} }; |
810 | my %unique_hash = |
811 | map { $_ => $hash->{$_} } |
812 | grep { exists $hash->{$_} } |
813 | @unique_cols; |
814 | |
815 | push @unique_hashes, \%unique_hash |
816 | if (scalar keys %unique_hash == scalar @unique_cols); |
817 | } |
818 | |
819 | my $row; |
820 | if (@unique_hashes) { |
821 | $row = $self->search(\@unique_hashes, { rows => 1 })->first; |
822 | if ($row) { |
823 | $row->set_columns($hash); |
824 | $row->update; |
825 | } |
826 | } |
827 | |
828 | unless ($row) { |
829 | $row = $self->create($hash); |
830 | } |
831 | |
832 | return $row; |
833 | } |
834 | |
64acc2bc |
835 | =head2 get_cache |
836 | |
837 | Gets the contents of the cache for the resultset. |
838 | |
839 | =cut |
840 | |
841 | sub get_cache { |
842 | my $self = shift; |
843 | return $self->{all_cache} || []; |
844 | } |
845 | |
846 | =head2 set_cache |
847 | |
848 | Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset. |
849 | |
850 | =cut |
851 | |
852 | sub set_cache { |
853 | my ( $self, $data ) = @_; |
854 | $self->throw_exception("set_cache requires an arrayref") |
855 | if ref $data ne 'ARRAY'; |
856 | my $result_class = $self->result_source->result_class; |
857 | foreach( @$data ) { |
858 | $self->throw_exception("cannot cache object of type '$_', expected '$result_class'") |
859 | if ref $_ ne $result_class; |
860 | } |
861 | $self->{all_cache} = $data; |
862 | } |
863 | |
864 | =head2 clear_cache |
865 | |
866 | Clears the cache for the resultset. |
867 | |
868 | =cut |
869 | |
870 | sub clear_cache { |
871 | my $self = shift; |
872 | $self->set_cache([]); |
873 | } |
874 | |
875 | =head2 related_resultset |
876 | |
877 | Returns a related resultset for the supplied relationship name. |
878 | |
879 | $rs = $rs->related_resultset('foo'); |
880 | |
881 | =cut |
882 | |
883 | sub related_resultset { |
884 | my ( $self, $rel, @rest ) = @_; |
885 | $self->{related_resultsets} ||= {}; |
886 | my $resultsets = $self->{related_resultsets}; |
887 | if( !exists $resultsets->{$rel} ) { |
888 | #warn "fetching related resultset for rel '$rel'"; |
889 | my $rel_obj = $self->result_source->relationship_info($rel); |
890 | $self->throw_exception( |
891 | "search_related: result source '" . $self->result_source->name . |
892 | "' has no such relationship ${rel}") |
893 | unless $rel_obj; #die Dumper $self->{attrs}; |
894 | my $rs; |
895 | if( $self->{attrs}->{cache} ) { |
896 | $rs = $self->search(undef); |
897 | } |
898 | else { |
899 | $rs = $self->search(undef, { join => $rel }); |
900 | } |
901 | #use Data::Dumper; die Dumper $rs->{attrs};#$rs = $self->search( undef ); |
902 | #use Data::Dumper; warn Dumper $self->{attrs}, Dumper $rs->{attrs}; |
903 | my $alias = (defined $rs->{attrs}{seen_join}{$rel} |
904 | && $rs->{attrs}{seen_join}{$rel} > 1 |
905 | ? join('_', $rel, $rs->{attrs}{seen_join}{$rel}) |
906 | : $rel); |
907 | $resultsets->{$rel} = |
908 | $self->result_source->schema->resultset($rel_obj->{class} |
909 | )->search( undef, |
910 | { %{$rs->{attrs}}, |
911 | alias => $alias, |
912 | select => undef(), |
913 | as => undef() } |
914 | )->search(@rest); |
915 | } |
916 | return $resultsets->{$rel}; |
917 | } |
918 | |
701da8c4 |
919 | =head2 throw_exception |
920 | |
921 | See Schema's throw_exception |
922 | |
923 | =cut |
924 | |
925 | sub throw_exception { |
926 | my $self=shift; |
927 | $self->result_source->schema->throw_exception(@_); |
928 | } |
929 | |
40dbc108 |
930 | =head1 ATTRIBUTES |
076652e8 |
931 | |
a33df5d4 |
932 | The resultset takes various attributes that modify its behavior. Here's an |
933 | overview of them: |
bfab575a |
934 | |
935 | =head2 order_by |
076652e8 |
936 | |
a33df5d4 |
937 | Which column(s) to order the results by. This is currently passed through |
938 | directly to SQL, so you can give e.g. C<foo DESC> for a descending order. |
076652e8 |
939 | |
87c4e602 |
940 | =head2 cols |
941 | |
942 | =head3 Arguments: (arrayref) |
976f3686 |
943 | |
a33df5d4 |
944 | Shortcut to request a particular set of columns to be retrieved. Adds |
945 | C<me.> onto the start of any column without a C<.> in it and sets C<select> |
946 | from that, then auto-populates C<as> from C<select> as normal. |
976f3686 |
947 | |
87c4e602 |
948 | =head2 include_columns |
949 | |
950 | =head3 Arguments: (arrayref) |
5ac6a044 |
951 | |
952 | Shortcut to include additional columns in the returned results - for example |
953 | |
954 | { include_columns => ['foo.name'], join => ['foo'] } |
955 | |
956 | would add a 'name' column to the information passed to object inflation |
957 | |
87c4e602 |
958 | =head2 select |
959 | |
960 | =head3 Arguments: (arrayref) |
976f3686 |
961 | |
4a28c340 |
962 | Indicates which columns should be selected from the storage. You can use |
963 | column names, or in the case of RDBMS back ends, function or stored procedure |
964 | names: |
965 | |
966 | $rs = $schema->resultset('Foo')->search( |
967 | {}, |
968 | { |
cf7b40ed |
969 | select => [ |
4a28c340 |
970 | 'column_name', |
971 | { count => 'column_to_count' }, |
972 | { sum => 'column_to_sum' } |
cf7b40ed |
973 | ] |
4a28c340 |
974 | } |
975 | ); |
976 | |
977 | When you use function/stored procedure names and do not supply an C<as> |
978 | attribute, the column names returned are storage-dependent. E.g. MySQL would |
979 | return a column named C<count(column_to_count)> in the above example. |
976f3686 |
980 | |
87c4e602 |
981 | =head2 as |
982 | |
983 | =head3 Arguments: (arrayref) |
076652e8 |
984 | |
4a28c340 |
985 | Indicates column names for object inflation. This is used in conjunction with |
986 | C<select>, usually when C<select> contains one or more function or stored |
987 | procedure names: |
988 | |
989 | $rs = $schema->resultset('Foo')->search( |
990 | {}, |
991 | { |
cf7b40ed |
992 | select => [ |
4a28c340 |
993 | 'column1', |
994 | { count => 'column2' } |
cf7b40ed |
995 | ], |
4a28c340 |
996 | as => [qw/ column1 column2_count /] |
997 | } |
998 | ); |
999 | |
1000 | my $foo = $rs->first(); # get the first Foo |
1001 | |
1002 | If the object against which the search is performed already has an accessor |
1003 | matching a column name specified in C<as>, the value can be retrieved using |
1004 | the accessor as normal: |
1005 | |
1006 | my $column1 = $foo->column1(); |
1007 | |
1008 | If on the other hand an accessor does not exist in the object, you need to |
1009 | use C<get_column> instead: |
1010 | |
1011 | my $column2_count = $foo->get_column('column2_count'); |
1012 | |
1013 | You can create your own accessors if required - see |
1014 | L<DBIx::Class::Manual::Cookbook> for details. |
ee38fa40 |
1015 | |
bfab575a |
1016 | =head2 join |
ee38fa40 |
1017 | |
a33df5d4 |
1018 | Contains a list of relationships that should be joined for this query. For |
1019 | example: |
1020 | |
1021 | # Get CDs by Nine Inch Nails |
1022 | my $rs = $schema->resultset('CD')->search( |
1023 | { 'artist.name' => 'Nine Inch Nails' }, |
1024 | { join => 'artist' } |
1025 | ); |
1026 | |
1027 | Can also contain a hash reference to refer to the other relation's relations. |
1028 | For example: |
1029 | |
1030 | package MyApp::Schema::Track; |
1031 | use base qw/DBIx::Class/; |
1032 | __PACKAGE__->table('track'); |
1033 | __PACKAGE__->add_columns(qw/trackid cd position title/); |
1034 | __PACKAGE__->set_primary_key('trackid'); |
1035 | __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD'); |
1036 | 1; |
1037 | |
1038 | # In your application |
1039 | my $rs = $schema->resultset('Artist')->search( |
1040 | { 'track.title' => 'Teardrop' }, |
1041 | { |
1042 | join => { cd => 'track' }, |
1043 | order_by => 'artist.name', |
1044 | } |
1045 | ); |
1046 | |
2cb360cc |
1047 | If the same join is supplied twice, it will be aliased to <rel>_2 (and |
1048 | similarly for a third time). For e.g. |
1049 | |
1050 | my $rs = $schema->resultset('Artist')->search( |
1051 | { 'cds.title' => 'Foo', |
1052 | 'cds_2.title' => 'Bar' }, |
1053 | { join => [ qw/cds cds/ ] }); |
1054 | |
1055 | will return a set of all artists that have both a cd with title Foo and a cd |
1056 | with title Bar. |
1057 | |
1058 | If you want to fetch related objects from other tables as well, see C<prefetch> |
ae1c90a1 |
1059 | below. |
ee38fa40 |
1060 | |
87c4e602 |
1061 | =head2 prefetch |
1062 | |
1063 | =head3 Arguments: arrayref/hashref |
ee38fa40 |
1064 | |
ae1c90a1 |
1065 | Contains one or more relationships that should be fetched along with the main |
bfab575a |
1066 | query (when they are accessed afterwards they will have already been |
a33df5d4 |
1067 | "prefetched"). This is useful for when you know you will need the related |
ae1c90a1 |
1068 | objects, because it saves at least one query: |
1069 | |
1070 | my $rs = $schema->resultset('Tag')->search( |
1071 | {}, |
1072 | { |
1073 | prefetch => { |
1074 | cd => 'artist' |
1075 | } |
1076 | } |
1077 | ); |
1078 | |
1079 | The initial search results in SQL like the following: |
1080 | |
1081 | SELECT tag.*, cd.*, artist.* FROM tag |
1082 | JOIN cd ON tag.cd = cd.cdid |
1083 | JOIN artist ON cd.artist = artist.artistid |
1084 | |
1085 | L<DBIx::Class> has no need to go back to the database when we access the |
1086 | C<cd> or C<artist> relationships, which saves us two SQL statements in this |
1087 | case. |
1088 | |
2cb360cc |
1089 | Simple prefetches will be joined automatically, so there is no need |
1090 | for a C<join> attribute in the above search. If you're prefetching to |
1091 | depth (e.g. { cd => { artist => 'label' } or similar), you'll need to |
1092 | specify the join as well. |
ae1c90a1 |
1093 | |
1094 | C<prefetch> can be used with the following relationship types: C<belongs_to>, |
2cb360cc |
1095 | C<has_one> (or if you're using C<add_relationship>, any relationship declared |
1096 | with an accessor type of 'single' or 'filter'). |
ee38fa40 |
1097 | |
87c4e602 |
1098 | =head2 from |
1099 | |
1100 | =head3 Arguments: (arrayref) |
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1101 | |
4a28c340 |
1102 | The C<from> attribute gives you manual control over the C<FROM> clause of SQL |
1103 | statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN> |
1104 | clauses. |
ee38fa40 |
1105 | |
a33df5d4 |
1106 | NOTE: Use this on your own risk. This allows you to shoot off your foot! |
4a28c340 |
1107 | C<join> will usually do what you need and it is strongly recommended that you |
1108 | avoid using C<from> unless you cannot achieve the desired result using C<join>. |
1109 | |
1110 | In simple terms, C<from> works as follows: |
1111 | |
1112 | [ |
1113 | { <alias> => <table>, -join-type => 'inner|left|right' } |
1114 | [] # nested JOIN (optional) |
1115 | { <table.column> = <foreign_table.foreign_key> } |
1116 | ] |
1117 | |
1118 | JOIN |
1119 | <alias> <table> |
1120 | [JOIN ...] |
1121 | ON <table.column> = <foreign_table.foreign_key> |
1122 | |
1123 | An easy way to follow the examples below is to remember the following: |
1124 | |
1125 | Anything inside "[]" is a JOIN |
1126 | Anything inside "{}" is a condition for the enclosing JOIN |
1127 | |
1128 | The following examples utilize a "person" table in a family tree application. |
1129 | In order to express parent->child relationships, this table is self-joined: |
1130 | |
1131 | # Person->belongs_to('father' => 'Person'); |
1132 | # Person->belongs_to('mother' => 'Person'); |
1133 | |
1134 | C<from> can be used to nest joins. Here we return all children with a father, |
1135 | then search against all mothers of those children: |
1136 | |
1137 | $rs = $schema->resultset('Person')->search( |
1138 | {}, |
1139 | { |
1140 | alias => 'mother', # alias columns in accordance with "from" |
1141 | from => [ |
1142 | { mother => 'person' }, |
1143 | [ |
1144 | [ |
1145 | { child => 'person' }, |
1146 | [ |
1147 | { father => 'person' }, |
1148 | { 'father.person_id' => 'child.father_id' } |
1149 | ] |
1150 | ], |
1151 | { 'mother.person_id' => 'child.mother_id' } |
1152 | ], |
1153 | ] |
1154 | }, |
1155 | ); |
1156 | |
1157 | # Equivalent SQL: |
1158 | # SELECT mother.* FROM person mother |
1159 | # JOIN ( |
1160 | # person child |
1161 | # JOIN person father |
1162 | # ON ( father.person_id = child.father_id ) |
1163 | # ) |
1164 | # ON ( mother.person_id = child.mother_id ) |
1165 | |
1166 | The type of any join can be controlled manually. To search against only people |
1167 | with a father in the person table, we could explicitly use C<INNER JOIN>: |
1168 | |
1169 | $rs = $schema->resultset('Person')->search( |
1170 | {}, |
1171 | { |
1172 | alias => 'child', # alias columns in accordance with "from" |
1173 | from => [ |
1174 | { child => 'person' }, |
1175 | [ |
1176 | { father => 'person', -join-type => 'inner' }, |
1177 | { 'father.id' => 'child.father_id' } |
1178 | ], |
1179 | ] |
1180 | }, |
1181 | ); |
1182 | |
1183 | # Equivalent SQL: |
1184 | # SELECT child.* FROM person child |
1185 | # INNER JOIN person father ON child.father_id = father.id |
ee38fa40 |
1186 | |
bfab575a |
1187 | =head2 page |
076652e8 |
1188 | |
a33df5d4 |
1189 | For a paged resultset, specifies which page to retrieve. Leave unset |
bfab575a |
1190 | for an unpaged resultset. |
076652e8 |
1191 | |
bfab575a |
1192 | =head2 rows |
076652e8 |
1193 | |
4a28c340 |
1194 | For a paged resultset, how many rows per page: |
1195 | |
1196 | rows => 10 |
1197 | |
1198 | Can also be used to simulate an SQL C<LIMIT>. |
076652e8 |
1199 | |
87c4e602 |
1200 | =head2 group_by |
1201 | |
1202 | =head3 Arguments: (arrayref) |
54540863 |
1203 | |
bda4c2b8 |
1204 | A arrayref of columns to group by. Can include columns of joined tables. |
54540863 |
1205 | |
675ce4a6 |
1206 | group_by => [qw/ column1 column2 ... /] |
1207 | |
54540863 |
1208 | =head2 distinct |
1209 | |
a33df5d4 |
1210 | Set to 1 to group by all columns. |
1211 | |
1212 | For more examples of using these attributes, see |
1213 | L<DBIx::Class::Manual::Cookbook>. |
54540863 |
1214 | |
bfab575a |
1215 | =cut |
076652e8 |
1216 | |
89c0a5a2 |
1217 | 1; |