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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 = $schema->resultset('Foo')->search(bar => 'baz'); |
ee38fa40 |
24 | |
25 | =head1 DESCRIPTION |
26 | |
bfab575a |
27 | The resultset is also known as an iterator. It is responsible for handling |
a33df5d4 |
28 | queries that may return an arbitrary number of rows, e.g. via L</search> |
bfab575a |
29 | or a C<has_many> relationship. |
ee38fa40 |
30 | |
a33df5d4 |
31 | In the examples below, the following table classes are used: |
32 | |
33 | package MyApp::Schema::Artist; |
34 | use base qw/DBIx::Class/; |
f4409169 |
35 | __PACKAGE__->load_components(qw/Core/); |
a33df5d4 |
36 | __PACKAGE__->table('artist'); |
37 | __PACKAGE__->add_columns(qw/artistid name/); |
38 | __PACKAGE__->set_primary_key('artistid'); |
39 | __PACKAGE__->has_many(cds => 'MyApp::Schema::CD'); |
40 | 1; |
41 | |
42 | package MyApp::Schema::CD; |
43 | use base qw/DBIx::Class/; |
f4409169 |
44 | __PACKAGE__->load_components(qw/Core/); |
45 | __PACKAGE__->table('cd'); |
a33df5d4 |
46 | __PACKAGE__->add_columns(qw/cdid artist title year/); |
47 | __PACKAGE__->set_primary_key('cdid'); |
48 | __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist'); |
49 | 1; |
50 | |
ee38fa40 |
51 | =head1 METHODS |
52 | |
87c4e602 |
53 | =head2 new |
54 | |
55 | =head3 Arguments: ($source, \%$attrs) |
ee38fa40 |
56 | |
a33df5d4 |
57 | The resultset constructor. Takes a source object (usually a |
80c90f5d |
58 | L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see L</ATRRIBUTES> |
a33df5d4 |
59 | below). Does not perform any queries -- these are executed as needed by the |
60 | other methods. |
61 | |
62 | Generally you won't need to construct a resultset manually. You'll |
63 | automatically get one from e.g. a L</search> called in scalar context: |
64 | |
65 | my $rs = $schema->resultset('CD')->search({ title => '100th Window' }); |
ee38fa40 |
66 | |
67 | =cut |
68 | |
89c0a5a2 |
69 | sub new { |
fea3d045 |
70 | my $class = shift; |
f9db5527 |
71 | return $class->new_result(@_) if ref $class; |
fea3d045 |
72 | my ($source, $attrs) = @_; |
b98e75f6 |
73 | #use Data::Dumper; warn Dumper($attrs); |
ea20d0fd |
74 | $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } }; |
c7ce65e6 |
75 | my %seen; |
6aeb9185 |
76 | my $alias = ($attrs->{alias} ||= 'me'); |
a9433341 |
77 | if ($attrs->{cols} || !$attrs->{select}) { |
78 | delete $attrs->{as} if $attrs->{cols}; |
976f3686 |
79 | my @cols = ($attrs->{cols} |
80 | ? @{delete $attrs->{cols}} |
a9433341 |
81 | : $source->columns); |
6aeb9185 |
82 | $attrs->{select} = [ map { m/\./ ? $_ : "${alias}.$_" } @cols ]; |
976f3686 |
83 | } |
6aeb9185 |
84 | $attrs->{as} ||= [ map { m/^$alias\.(.*)$/ ? $1 : $_ } @{$attrs->{select}} ]; |
5ac6a044 |
85 | if (my $include = delete $attrs->{include_columns}) { |
86 | push(@{$attrs->{select}}, @$include); |
87 | push(@{$attrs->{as}}, map { m/([^\.]+)$/; $1; } @$include); |
88 | } |
976f3686 |
89 | #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/}); |
fea3d045 |
90 | $attrs->{from} ||= [ { $alias => $source->from } ]; |
8fab5eef |
91 | $attrs->{seen_join} ||= {}; |
b52e9bf8 |
92 | if (my $join = delete $attrs->{join}) { |
93 | foreach my $j (ref $join eq 'ARRAY' |
94 | ? (@{$join}) : ($join)) { |
c7ce65e6 |
95 | if (ref $j eq 'HASH') { |
96 | $seen{$_} = 1 foreach keys %$j; |
97 | } else { |
98 | $seen{$j} = 1; |
99 | } |
100 | } |
8fab5eef |
101 | push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join})); |
c7ce65e6 |
102 | } |
54540863 |
103 | $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct}; |
b3e8ac9b |
104 | |
105 | if (my $prefetch = delete $attrs->{prefetch}) { |
106 | foreach my $p (ref $prefetch eq 'ARRAY' |
107 | ? (@{$prefetch}) : ($prefetch)) { |
108 | if( ref $p eq 'HASH' ) { |
109 | foreach my $key (keys %$p) { |
110 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
111 | unless $seen{$key}; |
112 | } |
113 | } |
114 | else { |
115 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
116 | unless $seen{$p}; |
117 | } |
489709af |
118 | my @prefetch = $source->resolve_prefetch($p, $attrs->{alias}); |
b3e8ac9b |
119 | #die Dumper \@cols; |
489709af |
120 | push(@{$attrs->{select}}, map { $_->[0] } @prefetch); |
121 | push(@{$attrs->{as}}, map { $_->[1] } @prefetch); |
b3e8ac9b |
122 | } |
fef5d100 |
123 | } |
b3e8ac9b |
124 | |
6aeb9185 |
125 | if ($attrs->{page}) { |
126 | $attrs->{rows} ||= 10; |
127 | $attrs->{offset} ||= 0; |
128 | $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1)); |
129 | } |
89c0a5a2 |
130 | my $new = { |
701da8c4 |
131 | result_source => $source, |
89c0a5a2 |
132 | cond => $attrs->{where}, |
0a3c5b43 |
133 | from => $attrs->{from}, |
3c5b25c5 |
134 | count => undef, |
93b004d3 |
135 | page => delete $attrs->{page}, |
3c5b25c5 |
136 | pager => undef, |
89c0a5a2 |
137 | attrs => $attrs }; |
2f5911b2 |
138 | bless ($new, $class); |
9229f20a |
139 | return $new; |
89c0a5a2 |
140 | } |
141 | |
bfab575a |
142 | =head2 search |
0a3c5b43 |
143 | |
87f0da6a |
144 | my @obj = $rs->search({ foo => 3 }); # "... WHERE foo = 3" |
145 | my $new_rs = $rs->search({ foo => 3 }); |
146 | |
6009260a |
147 | If you need to pass in additional attributes but no additional condition, |
a33df5d4 |
148 | call it as C<search({}, \%attrs);>. |
87f0da6a |
149 | |
a33df5d4 |
150 | # "SELECT foo, bar FROM $class_table" |
151 | my @all = $class->search({}, { cols => [qw/foo bar/] }); |
0a3c5b43 |
152 | |
153 | =cut |
154 | |
155 | sub search { |
156 | my $self = shift; |
157 | |
6009260a |
158 | #use Data::Dumper;warn Dumper(@_); |
ff7bb7a1 |
159 | my $rs; |
160 | if( @_ ) { |
161 | |
162 | my $attrs = { %{$self->{attrs}} }; |
163 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
164 | $attrs = { %$attrs, %{ pop(@_) } }; |
165 | } |
6009260a |
166 | |
ff7bb7a1 |
167 | my $where = (@_ ? ((@_ == 1 || ref $_[0] eq "HASH") ? shift : {@_}) : undef()); |
168 | if (defined $where) { |
169 | $where = (defined $attrs->{where} |
ad3d2d7c |
170 | ? { '-and' => |
171 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
172 | $where, $attrs->{where} ] } |
0a3c5b43 |
173 | : $where); |
ff7bb7a1 |
174 | $attrs->{where} = $where; |
175 | } |
0a3c5b43 |
176 | |
ff7bb7a1 |
177 | $rs = (ref $self)->new($self->result_source, $attrs); |
178 | } |
179 | else { |
180 | $rs = $self; |
181 | $rs->reset(); |
182 | } |
0a3c5b43 |
183 | return (wantarray ? $rs->all : $rs); |
184 | } |
185 | |
87f0da6a |
186 | =head2 search_literal |
187 | |
6009260a |
188 | my @obj = $rs->search_literal($literal_where_cond, @bind); |
189 | my $new_rs = $rs->search_literal($literal_where_cond, @bind); |
190 | |
191 | Pass a literal chunk of SQL to be added to the conditional part of the |
87f0da6a |
192 | resultset. |
6009260a |
193 | |
bfab575a |
194 | =cut |
195 | |
6009260a |
196 | sub search_literal { |
197 | my ($self, $cond, @vals) = @_; |
198 | my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {}); |
199 | $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ]; |
200 | return $self->search(\$cond, $attrs); |
201 | } |
0a3c5b43 |
202 | |
87c4e602 |
203 | =head2 find |
204 | |
205 | =head3 Arguments: (@colvalues) | (\%cols, \%attrs?) |
87f0da6a |
206 | |
207 | Finds a row based on its primary key or unique constraint. For example: |
208 | |
87f0da6a |
209 | my $cd = $schema->resultset('CD')->find(5); |
210 | |
211 | Also takes an optional C<key> attribute, to search by a specific key or unique |
212 | constraint. For example: |
213 | |
214 | my $cd = $schema->resultset('CD')->find_or_create( |
215 | { |
216 | artist => 'Massive Attack', |
217 | title => 'Mezzanine', |
218 | }, |
219 | { key => 'artist_title' } |
220 | ); |
221 | |
a33df5d4 |
222 | See also L</find_or_create> and L</update_or_create>. |
223 | |
87f0da6a |
224 | =cut |
716b3d29 |
225 | |
226 | sub find { |
227 | my ($self, @vals) = @_; |
228 | my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {}); |
87f0da6a |
229 | |
701da8c4 |
230 | my @cols = $self->result_source->primary_columns; |
87f0da6a |
231 | if (exists $attrs->{key}) { |
701da8c4 |
232 | my %uniq = $self->result_source->unique_constraints; |
87f0da6a |
233 | $self->( "Unknown key " . $attrs->{key} . " on " . $self->name ) |
234 | unless exists $uniq{$attrs->{key}}; |
235 | @cols = @{ $uniq{$attrs->{key}} }; |
236 | } |
237 | #use Data::Dumper; warn Dumper($attrs, @vals, @cols); |
701da8c4 |
238 | $self->throw_exception( "Can't find unless a primary key or unique constraint is defined" ) |
87f0da6a |
239 | unless @cols; |
240 | |
716b3d29 |
241 | my $query; |
242 | if (ref $vals[0] eq 'HASH') { |
01bc091e |
243 | $query = { %{$vals[0]} }; |
87f0da6a |
244 | } elsif (@cols == @vals) { |
716b3d29 |
245 | $query = {}; |
87f0da6a |
246 | @{$query}{@cols} = @vals; |
716b3d29 |
247 | } else { |
248 | $query = {@vals}; |
249 | } |
01bc091e |
250 | foreach (keys %$query) { |
251 | next if m/\./; |
252 | $query->{$self->{attrs}{alias}.'.'.$_} = delete $query->{$_}; |
253 | } |
716b3d29 |
254 | #warn Dumper($query); |
a04ab285 |
255 | return (keys %$attrs |
256 | ? $self->search($query,$attrs)->single |
257 | : $self->single($query)); |
716b3d29 |
258 | } |
259 | |
b52e9bf8 |
260 | =head2 search_related |
261 | |
262 | $rs->search_related('relname', $cond?, $attrs?); |
263 | |
a33df5d4 |
264 | Search the specified relationship. Optionally specify a condition for matching |
265 | records. |
266 | |
b52e9bf8 |
267 | =cut |
268 | |
6aeb9185 |
269 | sub search_related { |
64acc2bc |
270 | return shift->related_resultset(shift)->search(@_); |
6aeb9185 |
271 | } |
b52e9bf8 |
272 | |
bfab575a |
273 | =head2 cursor |
ee38fa40 |
274 | |
bfab575a |
275 | Returns a storage-driven cursor to the given resultset. |
ee38fa40 |
276 | |
277 | =cut |
278 | |
73f58123 |
279 | sub cursor { |
280 | my ($self) = @_; |
701da8c4 |
281 | my ($attrs) = $self->{attrs}; |
6aeb9185 |
282 | $attrs = { %$attrs }; |
73f58123 |
283 | return $self->{cursor} |
701da8c4 |
284 | ||= $self->result_source->storage->select($self->{from}, $attrs->{select}, |
73f58123 |
285 | $attrs->{where},$attrs); |
286 | } |
287 | |
a04ab285 |
288 | =head2 single |
289 | |
290 | Inflates the first result without creating a cursor |
291 | |
292 | =cut |
293 | |
294 | sub single { |
295 | my ($self, $extra) = @_; |
296 | my ($attrs) = $self->{attrs}; |
297 | $attrs = { %$attrs }; |
298 | if ($extra) { |
299 | if (defined $attrs->{where}) { |
300 | $attrs->{where} = { |
301 | '-and' |
302 | => [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
303 | delete $attrs->{where}, $extra ] |
304 | }; |
305 | } else { |
306 | $attrs->{where} = $extra; |
307 | } |
308 | } |
309 | my @data = $self->result_source->storage->select_single( |
310 | $self->{from}, $attrs->{select}, |
311 | $attrs->{where},$attrs); |
312 | return (@data ? $self->_construct_object(@data) : ()); |
313 | } |
314 | |
315 | |
87f0da6a |
316 | =head2 search_like |
317 | |
a33df5d4 |
318 | Perform a search, but use C<LIKE> instead of equality as the condition. Note |
319 | that this is simply a convenience method; you most likely want to use |
320 | L</search> with specific operators. |
321 | |
322 | For more information, see L<DBIx::Class::Manual::Cookbook>. |
87f0da6a |
323 | |
324 | =cut |
58a4bd18 |
325 | |
326 | sub search_like { |
327 | my $class = shift; |
328 | my $attrs = { }; |
329 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
330 | $attrs = pop(@_); |
331 | } |
332 | my $query = ref $_[0] eq "HASH" ? { %{shift()} }: {@_}; |
333 | $query->{$_} = { 'like' => $query->{$_} } for keys %$query; |
334 | return $class->search($query, { %$attrs }); |
335 | } |
336 | |
87c4e602 |
337 | =head2 slice |
338 | |
339 | =head3 Arguments: ($first, $last) |
ee38fa40 |
340 | |
bfab575a |
341 | Returns a subset of elements from the resultset. |
ee38fa40 |
342 | |
343 | =cut |
344 | |
89c0a5a2 |
345 | sub slice { |
346 | my ($self, $min, $max) = @_; |
347 | my $attrs = { %{ $self->{attrs} || {} } }; |
6aeb9185 |
348 | $attrs->{offset} ||= 0; |
349 | $attrs->{offset} += $min; |
89c0a5a2 |
350 | $attrs->{rows} = ($max ? ($max - $min + 1) : 1); |
701da8c4 |
351 | my $slice = (ref $self)->new($self->result_source, $attrs); |
89c0a5a2 |
352 | return (wantarray ? $slice->all : $slice); |
353 | } |
354 | |
87f0da6a |
355 | =head2 next |
ee38fa40 |
356 | |
a33df5d4 |
357 | Returns the next element in the resultset (C<undef> is there is none). |
358 | |
359 | Can be used to efficiently iterate over records in the resultset: |
360 | |
361 | my $rs = $schema->resultset('CD')->search({}); |
362 | while (my $cd = $rs->next) { |
363 | print $cd->title; |
364 | } |
ee38fa40 |
365 | |
366 | =cut |
367 | |
89c0a5a2 |
368 | sub next { |
369 | my ($self) = @_; |
64acc2bc |
370 | my $cache = $self->get_cache; |
371 | if( @$cache ) { |
372 | $self->{all_cache_position} ||= 0; |
373 | my $obj = $cache->[$self->{all_cache_position}]; |
374 | $self->{all_cache_position}++; |
375 | return $obj; |
376 | } |
73f58123 |
377 | my @row = $self->cursor->next; |
a953d8d9 |
378 | # warn Dumper(\@row); use Data::Dumper; |
89c0a5a2 |
379 | return unless (@row); |
c7ce65e6 |
380 | return $self->_construct_object(@row); |
381 | } |
382 | |
383 | sub _construct_object { |
384 | my ($self, @row) = @_; |
64acc2bc |
385 | my @row_orig = @row; # copy @row for key comparison later, because @row will change |
b3e8ac9b |
386 | my @as = @{ $self->{attrs}{as} }; |
f9cc31dd |
387 | #use Data::Dumper; warn Dumper \@as; |
976f3686 |
388 | #warn "@cols -> @row"; |
b3e8ac9b |
389 | my $info = [ {}, {} ]; |
390 | foreach my $as (@as) { |
64acc2bc |
391 | my $rs = $self; |
b3e8ac9b |
392 | my $target = $info; |
393 | my @parts = split(/\./, $as); |
394 | my $col = pop(@parts); |
395 | foreach my $p (@parts) { |
396 | $target = $target->[1]->{$p} ||= []; |
64acc2bc |
397 | |
f9cc31dd |
398 | $rs = $rs->related_resultset($p) if $rs->{attrs}->{cache}; |
c7ce65e6 |
399 | } |
f9cc31dd |
400 | |
64acc2bc |
401 | $target->[0]->{$col} = shift @row |
402 | if ref($target->[0]) ne 'ARRAY'; # arrayref is pre-inflated objects, do not overwrite |
c7ce65e6 |
403 | } |
b3e8ac9b |
404 | #use Data::Dumper; warn Dumper(\@as, $info); |
701da8c4 |
405 | my $new = $self->result_source->result_class->inflate_result( |
406 | $self->result_source, @$info); |
33ce49d6 |
407 | $new = $self->{attrs}{record_filter}->($new) |
408 | if exists $self->{attrs}{record_filter}; |
f9cc31dd |
409 | |
410 | if( $self->{attrs}->{cache} ) { |
411 | while( my( $rel, $rs ) = each( %{$self->{related_resultsets}} ) ) { |
412 | $rs->all; |
413 | #warn "$rel:", @{$rs->get_cache}; |
414 | } |
415 | $self->build_rr( $self, $new ); |
416 | } |
417 | |
33ce49d6 |
418 | return $new; |
89c0a5a2 |
419 | } |
f9cc31dd |
420 | |
421 | sub build_rr { |
422 | # build related resultsets for supplied object |
423 | my ( $self, $context, $obj ) = @_; |
424 | |
425 | my $re = qr/^\w+\./; |
426 | while( my ($rel, $rs) = each( %{$context->{related_resultsets}} ) ) { |
427 | #warn "context:", $context->result_source->name, ", rel:$rel, rs:", $rs->result_source->name; |
428 | my @objs = (); |
429 | my $map = {}; |
430 | my $cond = $context->result_source->relationship_info($rel)->{cond}; |
431 | keys %$cond; |
432 | while( my( $rel_key, $pk ) = each(%$cond) ) { |
433 | $rel_key =~ s/$re//; |
434 | $pk =~ s/$re//; |
435 | $map->{$rel_key} = $pk; |
436 | } |
437 | |
438 | $rs->reset(); |
439 | while( my $rel_obj = $rs->next ) { |
440 | while( my( $rel_key, $pk ) = each(%$map) ) { |
441 | if( $rel_obj->get_column($rel_key) eq $obj->get_column($pk) ) { |
442 | push @objs, $rel_obj; |
443 | } |
444 | } |
445 | } |
446 | |
447 | my $rel_rs = $obj->related_resultset($rel); |
448 | $rel_rs->{attrs}->{cache} = 1; |
449 | $rel_rs->set_cache( \@objs ); |
450 | |
451 | while( my $rel_obj = $rel_rs->next ) { |
452 | $self->build_rr( $rs, $rel_obj ); |
453 | } |
454 | |
455 | } |
456 | |
457 | } |
89c0a5a2 |
458 | |
87c4e602 |
459 | =head2 result_source |
701da8c4 |
460 | |
461 | Returns a reference to the result source for this recordset. |
462 | |
463 | =cut |
464 | |
465 | |
bfab575a |
466 | =head2 count |
ee38fa40 |
467 | |
bfab575a |
468 | Performs an SQL C<COUNT> with the same query as the resultset was built |
6009260a |
469 | with to find the number of elements. If passed arguments, does a search |
470 | on the resultset and counts the results of that. |
ee38fa40 |
471 | |
bda4c2b8 |
472 | Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY> |
473 | using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do |
474 | not support C<DISTINCT> with multiple columns. If you are using such a |
475 | database, you should only use columns from the main table in your C<group_by> |
476 | clause. |
477 | |
ee38fa40 |
478 | =cut |
479 | |
89c0a5a2 |
480 | sub count { |
6009260a |
481 | my $self = shift; |
482 | return $self->search(@_)->count if @_ && defined $_[0]; |
6aeb9185 |
483 | unless (defined $self->{count}) { |
64acc2bc |
484 | return scalar @{ $self->get_cache } |
485 | if @{ $self->get_cache }; |
15c382be |
486 | my $group_by; |
487 | my $select = { 'count' => '*' }; |
488 | if( $group_by = delete $self->{attrs}{group_by} ) { |
dec2517f |
489 | my @distinct = (ref $group_by ? @$group_by : ($group_by)); |
15c382be |
490 | # todo: try CONCAT for multi-column pk |
491 | my @pk = $self->result_source->primary_columns; |
492 | if( scalar(@pk) == 1 ) { |
493 | my $pk = shift(@pk); |
494 | my $alias = $self->{attrs}{alias}; |
495 | my $re = qr/^($alias\.)?$pk$/; |
d0f1e63f |
496 | foreach my $column ( @distinct) { |
15c382be |
497 | if( $column =~ $re ) { |
498 | @distinct = ( $column ); |
499 | last; |
500 | } |
501 | } |
502 | } |
503 | |
504 | $select = { count => { 'distinct' => \@distinct } }; |
505 | #use Data::Dumper; die Dumper $select; |
506 | } |
507 | |
976f3686 |
508 | my $attrs = { %{ $self->{attrs} }, |
15c382be |
509 | select => $select, |
54540863 |
510 | as => [ 'count' ] }; |
ea20d0fd |
511 | # offset, order by and page are not needed to count. record_filter is cdbi |
512 | delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/; |
3c5b25c5 |
513 | |
701da8c4 |
514 | ($self->{count}) = (ref $self)->new($self->result_source, $attrs)->cursor->next; |
15c382be |
515 | $self->{attrs}{group_by} = $group_by; |
3c5b25c5 |
516 | } |
517 | return 0 unless $self->{count}; |
6aeb9185 |
518 | my $count = $self->{count}; |
519 | $count -= $self->{attrs}{offset} if $self->{attrs}{offset}; |
520 | $count = $self->{attrs}{rows} if |
521 | ($self->{attrs}{rows} && $self->{attrs}{rows} < $count); |
522 | return $count; |
89c0a5a2 |
523 | } |
524 | |
bfab575a |
525 | =head2 count_literal |
6009260a |
526 | |
a33df5d4 |
527 | Calls L</search_literal> with the passed arguments, then L</count>. |
6009260a |
528 | |
529 | =cut |
530 | |
531 | sub count_literal { shift->search_literal(@_)->count; } |
532 | |
bfab575a |
533 | =head2 all |
ee38fa40 |
534 | |
bfab575a |
535 | Returns all elements in the resultset. Called implictly if the resultset |
536 | is returned in list context. |
ee38fa40 |
537 | |
538 | =cut |
539 | |
89c0a5a2 |
540 | sub all { |
541 | my ($self) = @_; |
64acc2bc |
542 | return @{ $self->get_cache } |
543 | if @{ $self->get_cache }; |
544 | if( $self->{attrs}->{cache} ) { |
545 | my @obj = map { $self->_construct_object(@$_); } |
546 | $self->cursor->all; |
547 | $self->set_cache( \@obj ); |
548 | return @{ $self->get_cache }; |
549 | } |
c7ce65e6 |
550 | return map { $self->_construct_object(@$_); } |
73f58123 |
551 | $self->cursor->all; |
89c0a5a2 |
552 | } |
553 | |
bfab575a |
554 | =head2 reset |
ee38fa40 |
555 | |
bfab575a |
556 | Resets the resultset's cursor, so you can iterate through the elements again. |
ee38fa40 |
557 | |
558 | =cut |
559 | |
89c0a5a2 |
560 | sub reset { |
561 | my ($self) = @_; |
64acc2bc |
562 | $self->{all_cache_position} = 0; |
73f58123 |
563 | $self->cursor->reset; |
89c0a5a2 |
564 | return $self; |
565 | } |
566 | |
bfab575a |
567 | =head2 first |
ee38fa40 |
568 | |
bfab575a |
569 | Resets the resultset and returns the first element. |
ee38fa40 |
570 | |
571 | =cut |
572 | |
89c0a5a2 |
573 | sub first { |
574 | return $_[0]->reset->next; |
575 | } |
576 | |
87c4e602 |
577 | =head2 update |
578 | |
579 | =head3 Arguments: (\%values) |
c01ab172 |
580 | |
a33df5d4 |
581 | Sets the specified columns in the resultset to the supplied values. |
c01ab172 |
582 | |
583 | =cut |
584 | |
585 | sub update { |
586 | my ($self, $values) = @_; |
701da8c4 |
587 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
588 | return $self->result_source->storage->update( |
589 | $self->result_source->from, $values, $self->{cond}); |
c01ab172 |
590 | } |
591 | |
87c4e602 |
592 | =head2 update_all |
593 | |
594 | =head3 Arguments: (\%values) |
c01ab172 |
595 | |
a33df5d4 |
596 | Fetches all objects and updates them one at a time. Note that C<update_all> |
597 | will run cascade triggers while L</update> will not. |
c01ab172 |
598 | |
599 | =cut |
600 | |
601 | sub update_all { |
602 | my ($self, $values) = @_; |
701da8c4 |
603 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
c01ab172 |
604 | foreach my $obj ($self->all) { |
605 | $obj->set_columns($values)->update; |
606 | } |
607 | return 1; |
608 | } |
609 | |
bfab575a |
610 | =head2 delete |
ee38fa40 |
611 | |
c01ab172 |
612 | Deletes the contents of the resultset from its result source. |
ee38fa40 |
613 | |
614 | =cut |
615 | |
28927b50 |
616 | sub delete { |
89c0a5a2 |
617 | my ($self) = @_; |
ca4b5ab7 |
618 | my $del = {}; |
619 | $self->throw_exception("Can't delete on resultset with condition unless hash or array") |
620 | unless (ref($self->{cond}) eq 'HASH' || ref($self->{cond}) eq 'ARRAY'); |
621 | if (ref $self->{cond} eq 'ARRAY') { |
622 | $del = [ map { my %hash; |
623 | foreach my $key (keys %{$_}) { |
624 | $key =~ /([^\.]+)$/; |
625 | $hash{$1} = $_->{$key}; |
626 | }; \%hash; } @{$self->{cond}} ]; |
627 | } elsif ((keys %{$self->{cond}})[0] eq '-and') { |
628 | $del->{-and} = [ map { my %hash; |
629 | foreach my $key (keys %{$_}) { |
630 | $key =~ /([^\.]+)$/; |
631 | $hash{$1} = $_->{$key}; |
632 | }; \%hash; } @{$self->{cond}{-and}} ]; |
633 | } else { |
634 | foreach my $key (keys %{$self->{cond}}) { |
635 | $key =~ /([^\.]+)$/; |
636 | $del->{$1} = $self->{cond}{$key}; |
637 | } |
638 | } |
639 | $self->result_source->storage->delete($self->result_source->from, $del); |
89c0a5a2 |
640 | return 1; |
641 | } |
642 | |
c01ab172 |
643 | =head2 delete_all |
644 | |
a33df5d4 |
645 | Fetches all objects and deletes them one at a time. Note that C<delete_all> |
646 | will run cascade triggers while L</delete> will not. |
c01ab172 |
647 | |
648 | =cut |
649 | |
650 | sub delete_all { |
651 | my ($self) = @_; |
652 | $_->delete for $self->all; |
653 | return 1; |
654 | } |
28927b50 |
655 | |
bfab575a |
656 | =head2 pager |
ee38fa40 |
657 | |
658 | Returns a L<Data::Page> object for the current resultset. Only makes |
a33df5d4 |
659 | sense for queries with a C<page> attribute. |
ee38fa40 |
660 | |
661 | =cut |
662 | |
3c5b25c5 |
663 | sub pager { |
664 | my ($self) = @_; |
665 | my $attrs = $self->{attrs}; |
701da8c4 |
666 | $self->throw_exception("Can't create pager for non-paged rs") unless $self->{page}; |
6aeb9185 |
667 | $attrs->{rows} ||= 10; |
668 | $self->count; |
669 | return $self->{pager} ||= Data::Page->new( |
93b004d3 |
670 | $self->{count}, $attrs->{rows}, $self->{page}); |
3c5b25c5 |
671 | } |
672 | |
87c4e602 |
673 | =head2 page |
674 | |
675 | =head3 Arguments: ($page_num) |
ee38fa40 |
676 | |
bfab575a |
677 | Returns a new resultset for the specified page. |
ee38fa40 |
678 | |
679 | =cut |
680 | |
3c5b25c5 |
681 | sub page { |
682 | my ($self, $page) = @_; |
6aeb9185 |
683 | my $attrs = { %{$self->{attrs}} }; |
3c5b25c5 |
684 | $attrs->{page} = $page; |
701da8c4 |
685 | return (ref $self)->new($self->result_source, $attrs); |
fea3d045 |
686 | } |
687 | |
87c4e602 |
688 | =head2 new_result |
689 | |
690 | =head3 Arguments: (\%vals) |
fea3d045 |
691 | |
87f0da6a |
692 | Creates a result in the resultset's result class. |
fea3d045 |
693 | |
694 | =cut |
695 | |
696 | sub new_result { |
697 | my ($self, $values) = @_; |
701da8c4 |
698 | $self->throw_exception( "new_result needs a hash" ) |
fea3d045 |
699 | unless (ref $values eq 'HASH'); |
701da8c4 |
700 | $self->throw_exception( "Can't abstract implicit construct, condition not a hash" ) |
fea3d045 |
701 | if ($self->{cond} && !(ref $self->{cond} eq 'HASH')); |
702 | my %new = %$values; |
703 | my $alias = $self->{attrs}{alias}; |
704 | foreach my $key (keys %{$self->{cond}||{}}) { |
705 | $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:$alias\.)?([^\.]+)$/); |
706 | } |
701da8c4 |
707 | my $obj = $self->result_source->result_class->new(\%new); |
708 | $obj->result_source($self->result_source) if $obj->can('result_source'); |
097d3227 |
709 | $obj; |
fea3d045 |
710 | } |
711 | |
87c4e602 |
712 | =head2 create |
713 | |
714 | =head3 Arguments: (\%vals) |
fea3d045 |
715 | |
87f0da6a |
716 | Inserts a record into the resultset and returns the object. |
fea3d045 |
717 | |
a33df5d4 |
718 | Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. |
fea3d045 |
719 | |
720 | =cut |
721 | |
722 | sub create { |
723 | my ($self, $attrs) = @_; |
701da8c4 |
724 | $self->throw_exception( "create needs a hashref" ) unless ref $attrs eq 'HASH'; |
fea3d045 |
725 | return $self->new_result($attrs)->insert; |
3c5b25c5 |
726 | } |
727 | |
87c4e602 |
728 | =head2 find_or_create |
729 | |
730 | =head3 Arguments: (\%vals, \%attrs?) |
87f0da6a |
731 | |
732 | $class->find_or_create({ key => $val, ... }); |
c2b15ecc |
733 | |
c2b15ecc |
734 | Searches for a record matching the search condition; if it doesn't find one, |
cf7b40ed |
735 | creates one and returns that instead. |
87f0da6a |
736 | |
87f0da6a |
737 | my $cd = $schema->resultset('CD')->find_or_create({ |
738 | cdid => 5, |
739 | artist => 'Massive Attack', |
740 | title => 'Mezzanine', |
741 | year => 2005, |
742 | }); |
743 | |
744 | Also takes an optional C<key> attribute, to search by a specific key or unique |
745 | constraint. For example: |
746 | |
747 | my $cd = $schema->resultset('CD')->find_or_create( |
748 | { |
749 | artist => 'Massive Attack', |
750 | title => 'Mezzanine', |
751 | }, |
752 | { key => 'artist_title' } |
753 | ); |
754 | |
755 | See also L</find> and L</update_or_create>. |
756 | |
c2b15ecc |
757 | =cut |
758 | |
759 | sub find_or_create { |
760 | my $self = shift; |
87f0da6a |
761 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
762 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
763 | my $exists = $self->find($hash, $attrs); |
c2b15ecc |
764 | return defined($exists) ? $exists : $self->create($hash); |
765 | } |
766 | |
87f0da6a |
767 | =head2 update_or_create |
768 | |
769 | $class->update_or_create({ key => $val, ... }); |
770 | |
771 | First, search for an existing row matching one of the unique constraints |
772 | (including the primary key) on the source of this resultset. If a row is |
773 | found, update it with the other given column values. Otherwise, create a new |
774 | row. |
775 | |
776 | Takes an optional C<key> attribute to search on a specific unique constraint. |
777 | For example: |
778 | |
779 | # In your application |
780 | my $cd = $schema->resultset('CD')->update_or_create( |
781 | { |
782 | artist => 'Massive Attack', |
783 | title => 'Mezzanine', |
784 | year => 1998, |
785 | }, |
786 | { key => 'artist_title' } |
787 | ); |
788 | |
789 | If no C<key> is specified, it searches on all unique constraints defined on the |
790 | source, including the primary key. |
791 | |
792 | If the C<key> is specified as C<primary>, search only on the primary key. |
793 | |
a33df5d4 |
794 | See also L</find> and L</find_or_create>. |
795 | |
87f0da6a |
796 | =cut |
797 | |
798 | sub update_or_create { |
799 | my $self = shift; |
800 | |
801 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
802 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
803 | |
701da8c4 |
804 | my %unique_constraints = $self->result_source->unique_constraints; |
87f0da6a |
805 | my @constraint_names = (exists $attrs->{key} |
806 | ? ($attrs->{key}) |
807 | : keys %unique_constraints); |
808 | |
809 | my @unique_hashes; |
810 | foreach my $name (@constraint_names) { |
811 | my @unique_cols = @{ $unique_constraints{$name} }; |
812 | my %unique_hash = |
813 | map { $_ => $hash->{$_} } |
814 | grep { exists $hash->{$_} } |
815 | @unique_cols; |
816 | |
817 | push @unique_hashes, \%unique_hash |
818 | if (scalar keys %unique_hash == scalar @unique_cols); |
819 | } |
820 | |
821 | my $row; |
822 | if (@unique_hashes) { |
823 | $row = $self->search(\@unique_hashes, { rows => 1 })->first; |
824 | if ($row) { |
825 | $row->set_columns($hash); |
826 | $row->update; |
827 | } |
828 | } |
829 | |
830 | unless ($row) { |
831 | $row = $self->create($hash); |
832 | } |
833 | |
834 | return $row; |
835 | } |
836 | |
64acc2bc |
837 | =head2 get_cache |
838 | |
839 | Gets the contents of the cache for the resultset. |
840 | |
841 | =cut |
842 | |
843 | sub get_cache { |
844 | my $self = shift; |
845 | return $self->{all_cache} || []; |
846 | } |
847 | |
848 | =head2 set_cache |
849 | |
850 | Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset. |
851 | |
852 | =cut |
853 | |
854 | sub set_cache { |
855 | my ( $self, $data ) = @_; |
856 | $self->throw_exception("set_cache requires an arrayref") |
857 | if ref $data ne 'ARRAY'; |
858 | my $result_class = $self->result_source->result_class; |
859 | foreach( @$data ) { |
860 | $self->throw_exception("cannot cache object of type '$_', expected '$result_class'") |
861 | if ref $_ ne $result_class; |
862 | } |
863 | $self->{all_cache} = $data; |
864 | } |
865 | |
866 | =head2 clear_cache |
867 | |
868 | Clears the cache for the resultset. |
869 | |
870 | =cut |
871 | |
872 | sub clear_cache { |
873 | my $self = shift; |
874 | $self->set_cache([]); |
875 | } |
876 | |
877 | =head2 related_resultset |
878 | |
879 | Returns a related resultset for the supplied relationship name. |
880 | |
881 | $rs = $rs->related_resultset('foo'); |
882 | |
883 | =cut |
884 | |
885 | sub related_resultset { |
886 | my ( $self, $rel, @rest ) = @_; |
887 | $self->{related_resultsets} ||= {}; |
888 | my $resultsets = $self->{related_resultsets}; |
889 | if( !exists $resultsets->{$rel} ) { |
890 | #warn "fetching related resultset for rel '$rel'"; |
891 | my $rel_obj = $self->result_source->relationship_info($rel); |
892 | $self->throw_exception( |
893 | "search_related: result source '" . $self->result_source->name . |
894 | "' has no such relationship ${rel}") |
895 | unless $rel_obj; #die Dumper $self->{attrs}; |
896 | my $rs; |
897 | if( $self->{attrs}->{cache} ) { |
898 | $rs = $self->search(undef); |
899 | } |
900 | else { |
901 | $rs = $self->search(undef, { join => $rel }); |
902 | } |
903 | #use Data::Dumper; die Dumper $rs->{attrs};#$rs = $self->search( undef ); |
904 | #use Data::Dumper; warn Dumper $self->{attrs}, Dumper $rs->{attrs}; |
905 | my $alias = (defined $rs->{attrs}{seen_join}{$rel} |
906 | && $rs->{attrs}{seen_join}{$rel} > 1 |
907 | ? join('_', $rel, $rs->{attrs}{seen_join}{$rel}) |
908 | : $rel); |
909 | $resultsets->{$rel} = |
910 | $self->result_source->schema->resultset($rel_obj->{class} |
911 | )->search( undef, |
912 | { %{$rs->{attrs}}, |
913 | alias => $alias, |
914 | select => undef(), |
915 | as => undef() } |
916 | )->search(@rest); |
917 | } |
918 | return $resultsets->{$rel}; |
919 | } |
920 | |
701da8c4 |
921 | =head2 throw_exception |
922 | |
923 | See Schema's throw_exception |
924 | |
925 | =cut |
926 | |
927 | sub throw_exception { |
928 | my $self=shift; |
929 | $self->result_source->schema->throw_exception(@_); |
930 | } |
931 | |
40dbc108 |
932 | =head1 ATTRIBUTES |
076652e8 |
933 | |
a33df5d4 |
934 | The resultset takes various attributes that modify its behavior. Here's an |
935 | overview of them: |
bfab575a |
936 | |
937 | =head2 order_by |
076652e8 |
938 | |
a33df5d4 |
939 | Which column(s) to order the results by. This is currently passed through |
940 | directly to SQL, so you can give e.g. C<foo DESC> for a descending order. |
076652e8 |
941 | |
87c4e602 |
942 | =head2 cols |
943 | |
944 | =head3 Arguments: (arrayref) |
976f3686 |
945 | |
a33df5d4 |
946 | Shortcut to request a particular set of columns to be retrieved. Adds |
947 | C<me.> onto the start of any column without a C<.> in it and sets C<select> |
948 | from that, then auto-populates C<as> from C<select> as normal. |
976f3686 |
949 | |
87c4e602 |
950 | =head2 include_columns |
951 | |
952 | =head3 Arguments: (arrayref) |
5ac6a044 |
953 | |
954 | Shortcut to include additional columns in the returned results - for example |
955 | |
956 | { include_columns => ['foo.name'], join => ['foo'] } |
957 | |
958 | would add a 'name' column to the information passed to object inflation |
959 | |
87c4e602 |
960 | =head2 select |
961 | |
962 | =head3 Arguments: (arrayref) |
976f3686 |
963 | |
4a28c340 |
964 | Indicates which columns should be selected from the storage. You can use |
965 | column names, or in the case of RDBMS back ends, function or stored procedure |
966 | names: |
967 | |
968 | $rs = $schema->resultset('Foo')->search( |
969 | {}, |
970 | { |
cf7b40ed |
971 | select => [ |
4a28c340 |
972 | 'column_name', |
973 | { count => 'column_to_count' }, |
974 | { sum => 'column_to_sum' } |
cf7b40ed |
975 | ] |
4a28c340 |
976 | } |
977 | ); |
978 | |
979 | When you use function/stored procedure names and do not supply an C<as> |
980 | attribute, the column names returned are storage-dependent. E.g. MySQL would |
981 | return a column named C<count(column_to_count)> in the above example. |
976f3686 |
982 | |
87c4e602 |
983 | =head2 as |
984 | |
985 | =head3 Arguments: (arrayref) |
076652e8 |
986 | |
4a28c340 |
987 | Indicates column names for object inflation. This is used in conjunction with |
988 | C<select>, usually when C<select> contains one or more function or stored |
989 | procedure names: |
990 | |
991 | $rs = $schema->resultset('Foo')->search( |
992 | {}, |
993 | { |
cf7b40ed |
994 | select => [ |
4a28c340 |
995 | 'column1', |
996 | { count => 'column2' } |
cf7b40ed |
997 | ], |
4a28c340 |
998 | as => [qw/ column1 column2_count /] |
999 | } |
1000 | ); |
1001 | |
1002 | my $foo = $rs->first(); # get the first Foo |
1003 | |
1004 | If the object against which the search is performed already has an accessor |
1005 | matching a column name specified in C<as>, the value can be retrieved using |
1006 | the accessor as normal: |
1007 | |
1008 | my $column1 = $foo->column1(); |
1009 | |
1010 | If on the other hand an accessor does not exist in the object, you need to |
1011 | use C<get_column> instead: |
1012 | |
1013 | my $column2_count = $foo->get_column('column2_count'); |
1014 | |
1015 | You can create your own accessors if required - see |
1016 | L<DBIx::Class::Manual::Cookbook> for details. |
ee38fa40 |
1017 | |
bfab575a |
1018 | =head2 join |
ee38fa40 |
1019 | |
a33df5d4 |
1020 | Contains a list of relationships that should be joined for this query. For |
1021 | example: |
1022 | |
1023 | # Get CDs by Nine Inch Nails |
1024 | my $rs = $schema->resultset('CD')->search( |
1025 | { 'artist.name' => 'Nine Inch Nails' }, |
1026 | { join => 'artist' } |
1027 | ); |
1028 | |
1029 | Can also contain a hash reference to refer to the other relation's relations. |
1030 | For example: |
1031 | |
1032 | package MyApp::Schema::Track; |
1033 | use base qw/DBIx::Class/; |
1034 | __PACKAGE__->table('track'); |
1035 | __PACKAGE__->add_columns(qw/trackid cd position title/); |
1036 | __PACKAGE__->set_primary_key('trackid'); |
1037 | __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD'); |
1038 | 1; |
1039 | |
1040 | # In your application |
1041 | my $rs = $schema->resultset('Artist')->search( |
1042 | { 'track.title' => 'Teardrop' }, |
1043 | { |
1044 | join => { cd => 'track' }, |
1045 | order_by => 'artist.name', |
1046 | } |
1047 | ); |
1048 | |
2cb360cc |
1049 | If the same join is supplied twice, it will be aliased to <rel>_2 (and |
1050 | similarly for a third time). For e.g. |
1051 | |
1052 | my $rs = $schema->resultset('Artist')->search( |
1053 | { 'cds.title' => 'Foo', |
1054 | 'cds_2.title' => 'Bar' }, |
1055 | { join => [ qw/cds cds/ ] }); |
1056 | |
1057 | will return a set of all artists that have both a cd with title Foo and a cd |
1058 | with title Bar. |
1059 | |
1060 | If you want to fetch related objects from other tables as well, see C<prefetch> |
ae1c90a1 |
1061 | below. |
ee38fa40 |
1062 | |
87c4e602 |
1063 | =head2 prefetch |
1064 | |
1065 | =head3 Arguments: arrayref/hashref |
ee38fa40 |
1066 | |
ae1c90a1 |
1067 | Contains one or more relationships that should be fetched along with the main |
bfab575a |
1068 | query (when they are accessed afterwards they will have already been |
a33df5d4 |
1069 | "prefetched"). This is useful for when you know you will need the related |
ae1c90a1 |
1070 | objects, because it saves at least one query: |
1071 | |
1072 | my $rs = $schema->resultset('Tag')->search( |
1073 | {}, |
1074 | { |
1075 | prefetch => { |
1076 | cd => 'artist' |
1077 | } |
1078 | } |
1079 | ); |
1080 | |
1081 | The initial search results in SQL like the following: |
1082 | |
1083 | SELECT tag.*, cd.*, artist.* FROM tag |
1084 | JOIN cd ON tag.cd = cd.cdid |
1085 | JOIN artist ON cd.artist = artist.artistid |
1086 | |
1087 | L<DBIx::Class> has no need to go back to the database when we access the |
1088 | C<cd> or C<artist> relationships, which saves us two SQL statements in this |
1089 | case. |
1090 | |
2cb360cc |
1091 | Simple prefetches will be joined automatically, so there is no need |
1092 | for a C<join> attribute in the above search. If you're prefetching to |
1093 | depth (e.g. { cd => { artist => 'label' } or similar), you'll need to |
1094 | specify the join as well. |
ae1c90a1 |
1095 | |
1096 | C<prefetch> can be used with the following relationship types: C<belongs_to>, |
2cb360cc |
1097 | C<has_one> (or if you're using C<add_relationship>, any relationship declared |
1098 | with an accessor type of 'single' or 'filter'). |
ee38fa40 |
1099 | |
87c4e602 |
1100 | =head2 from |
1101 | |
1102 | =head3 Arguments: (arrayref) |
ee38fa40 |
1103 | |
4a28c340 |
1104 | The C<from> attribute gives you manual control over the C<FROM> clause of SQL |
1105 | statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN> |
1106 | clauses. |
ee38fa40 |
1107 | |
a33df5d4 |
1108 | NOTE: Use this on your own risk. This allows you to shoot off your foot! |
4a28c340 |
1109 | C<join> will usually do what you need and it is strongly recommended that you |
1110 | avoid using C<from> unless you cannot achieve the desired result using C<join>. |
1111 | |
1112 | In simple terms, C<from> works as follows: |
1113 | |
1114 | [ |
1115 | { <alias> => <table>, -join-type => 'inner|left|right' } |
1116 | [] # nested JOIN (optional) |
1117 | { <table.column> = <foreign_table.foreign_key> } |
1118 | ] |
1119 | |
1120 | JOIN |
1121 | <alias> <table> |
1122 | [JOIN ...] |
1123 | ON <table.column> = <foreign_table.foreign_key> |
1124 | |
1125 | An easy way to follow the examples below is to remember the following: |
1126 | |
1127 | Anything inside "[]" is a JOIN |
1128 | Anything inside "{}" is a condition for the enclosing JOIN |
1129 | |
1130 | The following examples utilize a "person" table in a family tree application. |
1131 | In order to express parent->child relationships, this table is self-joined: |
1132 | |
1133 | # Person->belongs_to('father' => 'Person'); |
1134 | # Person->belongs_to('mother' => 'Person'); |
1135 | |
1136 | C<from> can be used to nest joins. Here we return all children with a father, |
1137 | then search against all mothers of those children: |
1138 | |
1139 | $rs = $schema->resultset('Person')->search( |
1140 | {}, |
1141 | { |
1142 | alias => 'mother', # alias columns in accordance with "from" |
1143 | from => [ |
1144 | { mother => 'person' }, |
1145 | [ |
1146 | [ |
1147 | { child => 'person' }, |
1148 | [ |
1149 | { father => 'person' }, |
1150 | { 'father.person_id' => 'child.father_id' } |
1151 | ] |
1152 | ], |
1153 | { 'mother.person_id' => 'child.mother_id' } |
1154 | ], |
1155 | ] |
1156 | }, |
1157 | ); |
1158 | |
1159 | # Equivalent SQL: |
1160 | # SELECT mother.* FROM person mother |
1161 | # JOIN ( |
1162 | # person child |
1163 | # JOIN person father |
1164 | # ON ( father.person_id = child.father_id ) |
1165 | # ) |
1166 | # ON ( mother.person_id = child.mother_id ) |
1167 | |
1168 | The type of any join can be controlled manually. To search against only people |
1169 | with a father in the person table, we could explicitly use C<INNER JOIN>: |
1170 | |
1171 | $rs = $schema->resultset('Person')->search( |
1172 | {}, |
1173 | { |
1174 | alias => 'child', # alias columns in accordance with "from" |
1175 | from => [ |
1176 | { child => 'person' }, |
1177 | [ |
1178 | { father => 'person', -join-type => 'inner' }, |
1179 | { 'father.id' => 'child.father_id' } |
1180 | ], |
1181 | ] |
1182 | }, |
1183 | ); |
1184 | |
1185 | # Equivalent SQL: |
1186 | # SELECT child.* FROM person child |
1187 | # INNER JOIN person father ON child.father_id = father.id |
ee38fa40 |
1188 | |
bfab575a |
1189 | =head2 page |
076652e8 |
1190 | |
a33df5d4 |
1191 | For a paged resultset, specifies which page to retrieve. Leave unset |
bfab575a |
1192 | for an unpaged resultset. |
076652e8 |
1193 | |
bfab575a |
1194 | =head2 rows |
076652e8 |
1195 | |
4a28c340 |
1196 | For a paged resultset, how many rows per page: |
1197 | |
1198 | rows => 10 |
1199 | |
1200 | Can also be used to simulate an SQL C<LIMIT>. |
076652e8 |
1201 | |
87c4e602 |
1202 | =head2 group_by |
1203 | |
1204 | =head3 Arguments: (arrayref) |
54540863 |
1205 | |
bda4c2b8 |
1206 | A arrayref of columns to group by. Can include columns of joined tables. |
54540863 |
1207 | |
675ce4a6 |
1208 | group_by => [qw/ column1 column2 ... /] |
1209 | |
54540863 |
1210 | =head2 distinct |
1211 | |
a33df5d4 |
1212 | Set to 1 to group by all columns. |
1213 | |
1214 | For more examples of using these attributes, see |
1215 | L<DBIx::Class::Manual::Cookbook>. |
54540863 |
1216 | |
bfab575a |
1217 | =cut |
076652e8 |
1218 | |
89c0a5a2 |
1219 | 1; |