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