Commit | Line | Data |
89c0a5a2 |
1 | package DBIx::Class::ResultSet; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | use overload |
ebaefbc2 |
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 |
181a28f4 |
58 | L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see L</ATTRIBUTES> |
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 | |
a86b1efe |
105 | $attrs->{order_by} = [ $attrs->{order_by} ] |
106 | if $attrs->{order_by} && !ref($attrs->{order_by}); |
107 | $attrs->{order_by} ||= []; |
108 | |
b3e8ac9b |
109 | if (my $prefetch = delete $attrs->{prefetch}) { |
110 | foreach my $p (ref $prefetch eq 'ARRAY' |
111 | ? (@{$prefetch}) : ($prefetch)) { |
112 | if( ref $p eq 'HASH' ) { |
113 | foreach my $key (keys %$p) { |
114 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
115 | unless $seen{$key}; |
116 | } |
117 | } |
118 | else { |
119 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
120 | unless $seen{$p}; |
121 | } |
a86b1efe |
122 | my @prefetch = $source->resolve_prefetch( |
123 | $p, $attrs->{alias}, {}, $attrs->{order_by}); |
b3e8ac9b |
124 | #die Dumper \@cols; |
489709af |
125 | push(@{$attrs->{select}}, map { $_->[0] } @prefetch); |
126 | push(@{$attrs->{as}}, map { $_->[1] } @prefetch); |
b3e8ac9b |
127 | } |
fef5d100 |
128 | } |
b3e8ac9b |
129 | |
6aeb9185 |
130 | if ($attrs->{page}) { |
131 | $attrs->{rows} ||= 10; |
132 | $attrs->{offset} ||= 0; |
133 | $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1)); |
134 | } |
89c0a5a2 |
135 | my $new = { |
701da8c4 |
136 | result_source => $source, |
89c0a5a2 |
137 | cond => $attrs->{where}, |
0a3c5b43 |
138 | from => $attrs->{from}, |
3c5b25c5 |
139 | count => undef, |
93b004d3 |
140 | page => delete $attrs->{page}, |
3c5b25c5 |
141 | pager => undef, |
89c0a5a2 |
142 | attrs => $attrs }; |
2f5911b2 |
143 | bless ($new, $class); |
9229f20a |
144 | return $new; |
89c0a5a2 |
145 | } |
146 | |
bfab575a |
147 | =head2 search |
0a3c5b43 |
148 | |
87f0da6a |
149 | my @obj = $rs->search({ foo => 3 }); # "... WHERE foo = 3" |
150 | my $new_rs = $rs->search({ foo => 3 }); |
151 | |
6009260a |
152 | If you need to pass in additional attributes but no additional condition, |
a33df5d4 |
153 | call it as C<search({}, \%attrs);>. |
87f0da6a |
154 | |
a33df5d4 |
155 | # "SELECT foo, bar FROM $class_table" |
156 | my @all = $class->search({}, { cols => [qw/foo bar/] }); |
0a3c5b43 |
157 | |
158 | =cut |
159 | |
160 | sub search { |
161 | my $self = shift; |
162 | |
ff7bb7a1 |
163 | my $rs; |
164 | if( @_ ) { |
165 | |
166 | my $attrs = { %{$self->{attrs}} }; |
8839560b |
167 | my $having = delete $attrs->{having}; |
ff7bb7a1 |
168 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
169 | $attrs = { %$attrs, %{ pop(@_) } }; |
170 | } |
6009260a |
171 | |
3e0e9e27 |
172 | my $where = (@_ |
173 | ? ((@_ == 1 || ref $_[0] eq "HASH") |
174 | ? shift |
175 | : ((@_ % 2) |
176 | ? $self->throw_exception( |
177 | "Odd number of arguments to search") |
178 | : {@_})) |
179 | : undef()); |
ff7bb7a1 |
180 | if (defined $where) { |
181 | $where = (defined $attrs->{where} |
ad3d2d7c |
182 | ? { '-and' => |
183 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
184 | $where, $attrs->{where} ] } |
0a3c5b43 |
185 | : $where); |
ff7bb7a1 |
186 | $attrs->{where} = $where; |
187 | } |
0a3c5b43 |
188 | |
8839560b |
189 | if (defined $having) { |
190 | $having = (defined $attrs->{having} |
191 | ? { '-and' => |
192 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
193 | $having, $attrs->{having} ] } |
194 | : $having); |
195 | $attrs->{having} = $having; |
196 | } |
197 | |
ff7bb7a1 |
198 | $rs = (ref $self)->new($self->result_source, $attrs); |
199 | } |
200 | else { |
201 | $rs = $self; |
202 | $rs->reset(); |
203 | } |
0a3c5b43 |
204 | return (wantarray ? $rs->all : $rs); |
205 | } |
206 | |
87f0da6a |
207 | =head2 search_literal |
208 | |
6009260a |
209 | my @obj = $rs->search_literal($literal_where_cond, @bind); |
210 | my $new_rs = $rs->search_literal($literal_where_cond, @bind); |
211 | |
212 | Pass a literal chunk of SQL to be added to the conditional part of the |
87f0da6a |
213 | resultset. |
6009260a |
214 | |
bfab575a |
215 | =cut |
fd9f5466 |
216 | |
6009260a |
217 | sub search_literal { |
218 | my ($self, $cond, @vals) = @_; |
219 | my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {}); |
220 | $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ]; |
221 | return $self->search(\$cond, $attrs); |
222 | } |
0a3c5b43 |
223 | |
87c4e602 |
224 | =head2 find |
225 | |
226 | =head3 Arguments: (@colvalues) | (\%cols, \%attrs?) |
87f0da6a |
227 | |
228 | Finds a row based on its primary key or unique constraint. For example: |
229 | |
87f0da6a |
230 | my $cd = $schema->resultset('CD')->find(5); |
231 | |
232 | Also takes an optional C<key> attribute, to search by a specific key or unique |
233 | constraint. For example: |
234 | |
fd9f5466 |
235 | my $cd = $schema->resultset('CD')->find( |
87f0da6a |
236 | { |
237 | artist => 'Massive Attack', |
238 | title => 'Mezzanine', |
239 | }, |
240 | { key => 'artist_title' } |
241 | ); |
242 | |
a33df5d4 |
243 | See also L</find_or_create> and L</update_or_create>. |
244 | |
87f0da6a |
245 | =cut |
716b3d29 |
246 | |
247 | sub find { |
248 | my ($self, @vals) = @_; |
249 | my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {}); |
87f0da6a |
250 | |
701da8c4 |
251 | my @cols = $self->result_source->primary_columns; |
87f0da6a |
252 | if (exists $attrs->{key}) { |
701da8c4 |
253 | my %uniq = $self->result_source->unique_constraints; |
87f0da6a |
254 | $self->( "Unknown key " . $attrs->{key} . " on " . $self->name ) |
255 | unless exists $uniq{$attrs->{key}}; |
256 | @cols = @{ $uniq{$attrs->{key}} }; |
257 | } |
258 | #use Data::Dumper; warn Dumper($attrs, @vals, @cols); |
701da8c4 |
259 | $self->throw_exception( "Can't find unless a primary key or unique constraint is defined" ) |
87f0da6a |
260 | unless @cols; |
261 | |
716b3d29 |
262 | my $query; |
263 | if (ref $vals[0] eq 'HASH') { |
01bc091e |
264 | $query = { %{$vals[0]} }; |
87f0da6a |
265 | } elsif (@cols == @vals) { |
716b3d29 |
266 | $query = {}; |
87f0da6a |
267 | @{$query}{@cols} = @vals; |
716b3d29 |
268 | } else { |
269 | $query = {@vals}; |
270 | } |
01bc091e |
271 | foreach (keys %$query) { |
272 | next if m/\./; |
273 | $query->{$self->{attrs}{alias}.'.'.$_} = delete $query->{$_}; |
274 | } |
716b3d29 |
275 | #warn Dumper($query); |
a04ab285 |
276 | return (keys %$attrs |
277 | ? $self->search($query,$attrs)->single |
278 | : $self->single($query)); |
716b3d29 |
279 | } |
280 | |
b52e9bf8 |
281 | =head2 search_related |
282 | |
283 | $rs->search_related('relname', $cond?, $attrs?); |
284 | |
a33df5d4 |
285 | Search the specified relationship. Optionally specify a condition for matching |
286 | records. |
287 | |
b52e9bf8 |
288 | =cut |
289 | |
6aeb9185 |
290 | sub search_related { |
64acc2bc |
291 | return shift->related_resultset(shift)->search(@_); |
6aeb9185 |
292 | } |
b52e9bf8 |
293 | |
bfab575a |
294 | =head2 cursor |
ee38fa40 |
295 | |
bfab575a |
296 | Returns a storage-driven cursor to the given resultset. |
ee38fa40 |
297 | |
298 | =cut |
299 | |
73f58123 |
300 | sub cursor { |
301 | my ($self) = @_; |
701da8c4 |
302 | my ($attrs) = $self->{attrs}; |
6aeb9185 |
303 | $attrs = { %$attrs }; |
73f58123 |
304 | return $self->{cursor} |
701da8c4 |
305 | ||= $self->result_source->storage->select($self->{from}, $attrs->{select}, |
73f58123 |
306 | $attrs->{where},$attrs); |
307 | } |
308 | |
a04ab285 |
309 | =head2 single |
310 | |
311 | Inflates the first result without creating a cursor |
312 | |
313 | =cut |
314 | |
315 | sub single { |
316 | my ($self, $extra) = @_; |
317 | my ($attrs) = $self->{attrs}; |
318 | $attrs = { %$attrs }; |
319 | if ($extra) { |
320 | if (defined $attrs->{where}) { |
321 | $attrs->{where} = { |
322 | '-and' |
323 | => [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
324 | delete $attrs->{where}, $extra ] |
325 | }; |
326 | } else { |
327 | $attrs->{where} = $extra; |
328 | } |
329 | } |
330 | my @data = $self->result_source->storage->select_single( |
331 | $self->{from}, $attrs->{select}, |
332 | $attrs->{where},$attrs); |
333 | return (@data ? $self->_construct_object(@data) : ()); |
334 | } |
335 | |
336 | |
87f0da6a |
337 | =head2 search_like |
338 | |
a33df5d4 |
339 | Perform a search, but use C<LIKE> instead of equality as the condition. Note |
340 | that this is simply a convenience method; you most likely want to use |
341 | L</search> with specific operators. |
342 | |
343 | For more information, see L<DBIx::Class::Manual::Cookbook>. |
87f0da6a |
344 | |
345 | =cut |
58a4bd18 |
346 | |
347 | sub search_like { |
348 | my $class = shift; |
349 | my $attrs = { }; |
350 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
351 | $attrs = pop(@_); |
352 | } |
353 | my $query = ref $_[0] eq "HASH" ? { %{shift()} }: {@_}; |
354 | $query->{$_} = { 'like' => $query->{$_} } for keys %$query; |
355 | return $class->search($query, { %$attrs }); |
356 | } |
357 | |
87c4e602 |
358 | =head2 slice |
359 | |
360 | =head3 Arguments: ($first, $last) |
ee38fa40 |
361 | |
bfab575a |
362 | Returns a subset of elements from the resultset. |
ee38fa40 |
363 | |
364 | =cut |
365 | |
89c0a5a2 |
366 | sub slice { |
367 | my ($self, $min, $max) = @_; |
368 | my $attrs = { %{ $self->{attrs} || {} } }; |
6aeb9185 |
369 | $attrs->{offset} ||= 0; |
370 | $attrs->{offset} += $min; |
89c0a5a2 |
371 | $attrs->{rows} = ($max ? ($max - $min + 1) : 1); |
701da8c4 |
372 | my $slice = (ref $self)->new($self->result_source, $attrs); |
89c0a5a2 |
373 | return (wantarray ? $slice->all : $slice); |
374 | } |
375 | |
87f0da6a |
376 | =head2 next |
ee38fa40 |
377 | |
a33df5d4 |
378 | Returns the next element in the resultset (C<undef> is there is none). |
379 | |
380 | Can be used to efficiently iterate over records in the resultset: |
381 | |
382 | my $rs = $schema->resultset('CD')->search({}); |
383 | while (my $cd = $rs->next) { |
384 | print $cd->title; |
385 | } |
ee38fa40 |
386 | |
387 | =cut |
388 | |
89c0a5a2 |
389 | sub next { |
390 | my ($self) = @_; |
3e0e9e27 |
391 | my $cache; |
392 | if( @{$cache = $self->{all_cache} || []}) { |
64acc2bc |
393 | $self->{all_cache_position} ||= 0; |
394 | my $obj = $cache->[$self->{all_cache_position}]; |
395 | $self->{all_cache_position}++; |
396 | return $obj; |
397 | } |
3e0e9e27 |
398 | if ($self->{attrs}{cache}) { |
399 | $self->{all_cache_position} = 0; |
400 | return ($self->all)[0]; |
401 | } |
a86b1efe |
402 | my @row = delete $self->{stashed_row} || $self->cursor->next; |
a953d8d9 |
403 | # warn Dumper(\@row); use Data::Dumper; |
89c0a5a2 |
404 | return unless (@row); |
c7ce65e6 |
405 | return $self->_construct_object(@row); |
406 | } |
407 | |
408 | sub _construct_object { |
409 | my ($self, @row) = @_; |
64acc2bc |
410 | my @row_orig = @row; # copy @row for key comparison later, because @row will change |
b3e8ac9b |
411 | my @as = @{ $self->{attrs}{as} }; |
f9cc31dd |
412 | #use Data::Dumper; warn Dumper \@as; |
976f3686 |
413 | #warn "@cols -> @row"; |
b3e8ac9b |
414 | my $info = [ {}, {} ]; |
415 | foreach my $as (@as) { |
64acc2bc |
416 | my $rs = $self; |
b3e8ac9b |
417 | my $target = $info; |
418 | my @parts = split(/\./, $as); |
419 | my $col = pop(@parts); |
420 | foreach my $p (@parts) { |
421 | $target = $target->[1]->{$p} ||= []; |
64acc2bc |
422 | |
f9cc31dd |
423 | $rs = $rs->related_resultset($p) if $rs->{attrs}->{cache}; |
c7ce65e6 |
424 | } |
f9cc31dd |
425 | |
64acc2bc |
426 | $target->[0]->{$col} = shift @row |
427 | if ref($target->[0]) ne 'ARRAY'; # arrayref is pre-inflated objects, do not overwrite |
c7ce65e6 |
428 | } |
b3e8ac9b |
429 | #use Data::Dumper; warn Dumper(\@as, $info); |
701da8c4 |
430 | my $new = $self->result_source->result_class->inflate_result( |
431 | $self->result_source, @$info); |
33ce49d6 |
432 | $new = $self->{attrs}{record_filter}->($new) |
433 | if exists $self->{attrs}{record_filter}; |
f9cc31dd |
434 | |
33ce49d6 |
435 | return $new; |
89c0a5a2 |
436 | } |
437 | |
87c4e602 |
438 | =head2 result_source |
701da8c4 |
439 | |
440 | Returns a reference to the result source for this recordset. |
441 | |
442 | =cut |
443 | |
444 | |
bfab575a |
445 | =head2 count |
ee38fa40 |
446 | |
bfab575a |
447 | Performs an SQL C<COUNT> with the same query as the resultset was built |
6009260a |
448 | with to find the number of elements. If passed arguments, does a search |
449 | on the resultset and counts the results of that. |
ee38fa40 |
450 | |
bda4c2b8 |
451 | Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY> |
452 | using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do |
453 | not support C<DISTINCT> with multiple columns. If you are using such a |
454 | database, you should only use columns from the main table in your C<group_by> |
455 | clause. |
456 | |
ee38fa40 |
457 | =cut |
458 | |
89c0a5a2 |
459 | sub count { |
6009260a |
460 | my $self = shift; |
461 | return $self->search(@_)->count if @_ && defined $_[0]; |
6aeb9185 |
462 | unless (defined $self->{count}) { |
64acc2bc |
463 | return scalar @{ $self->get_cache } |
464 | if @{ $self->get_cache }; |
15c382be |
465 | my $group_by; |
466 | my $select = { 'count' => '*' }; |
8839560b |
467 | my $attrs = { %{ $self->{attrs} } }; |
468 | if( $group_by = delete $attrs->{group_by} ) { |
469 | delete $attrs->{having}; |
dec2517f |
470 | my @distinct = (ref $group_by ? @$group_by : ($group_by)); |
15c382be |
471 | # todo: try CONCAT for multi-column pk |
472 | my @pk = $self->result_source->primary_columns; |
473 | if( scalar(@pk) == 1 ) { |
474 | my $pk = shift(@pk); |
8839560b |
475 | my $alias = $attrs->{alias}; |
15c382be |
476 | my $re = qr/^($alias\.)?$pk$/; |
d0f1e63f |
477 | foreach my $column ( @distinct) { |
15c382be |
478 | if( $column =~ $re ) { |
479 | @distinct = ( $column ); |
480 | last; |
481 | } |
482 | } |
483 | } |
484 | |
485 | $select = { count => { 'distinct' => \@distinct } }; |
486 | #use Data::Dumper; die Dumper $select; |
487 | } |
488 | |
8839560b |
489 | $attrs->{select} = $select; |
490 | $attrs->{as} = [ 'count' ]; |
ea20d0fd |
491 | # offset, order by and page are not needed to count. record_filter is cdbi |
492 | delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/; |
3c5b25c5 |
493 | |
701da8c4 |
494 | ($self->{count}) = (ref $self)->new($self->result_source, $attrs)->cursor->next; |
3c5b25c5 |
495 | } |
496 | return 0 unless $self->{count}; |
6aeb9185 |
497 | my $count = $self->{count}; |
498 | $count -= $self->{attrs}{offset} if $self->{attrs}{offset}; |
499 | $count = $self->{attrs}{rows} if |
500 | ($self->{attrs}{rows} && $self->{attrs}{rows} < $count); |
501 | return $count; |
89c0a5a2 |
502 | } |
503 | |
bfab575a |
504 | =head2 count_literal |
6009260a |
505 | |
a33df5d4 |
506 | Calls L</search_literal> with the passed arguments, then L</count>. |
6009260a |
507 | |
508 | =cut |
509 | |
510 | sub count_literal { shift->search_literal(@_)->count; } |
511 | |
bfab575a |
512 | =head2 all |
ee38fa40 |
513 | |
bfab575a |
514 | Returns all elements in the resultset. Called implictly if the resultset |
515 | is returned in list context. |
ee38fa40 |
516 | |
517 | =cut |
518 | |
89c0a5a2 |
519 | sub all { |
520 | my ($self) = @_; |
64acc2bc |
521 | return @{ $self->get_cache } |
522 | if @{ $self->get_cache }; |
523 | if( $self->{attrs}->{cache} ) { |
524 | my @obj = map { $self->_construct_object(@$_); } |
525 | $self->cursor->all; |
526 | $self->set_cache( \@obj ); |
3e0e9e27 |
527 | return @obj; |
64acc2bc |
528 | } |
c7ce65e6 |
529 | return map { $self->_construct_object(@$_); } |
73f58123 |
530 | $self->cursor->all; |
89c0a5a2 |
531 | } |
532 | |
bfab575a |
533 | =head2 reset |
ee38fa40 |
534 | |
bfab575a |
535 | Resets the resultset's cursor, so you can iterate through the elements again. |
ee38fa40 |
536 | |
537 | =cut |
538 | |
89c0a5a2 |
539 | sub reset { |
540 | my ($self) = @_; |
64acc2bc |
541 | $self->{all_cache_position} = 0; |
73f58123 |
542 | $self->cursor->reset; |
89c0a5a2 |
543 | return $self; |
544 | } |
545 | |
bfab575a |
546 | =head2 first |
ee38fa40 |
547 | |
bfab575a |
548 | Resets the resultset and returns the first element. |
ee38fa40 |
549 | |
550 | =cut |
551 | |
89c0a5a2 |
552 | sub first { |
553 | return $_[0]->reset->next; |
554 | } |
555 | |
87c4e602 |
556 | =head2 update |
557 | |
558 | =head3 Arguments: (\%values) |
c01ab172 |
559 | |
a33df5d4 |
560 | Sets the specified columns in the resultset to the supplied values. |
c01ab172 |
561 | |
562 | =cut |
563 | |
564 | sub update { |
565 | my ($self, $values) = @_; |
701da8c4 |
566 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
567 | return $self->result_source->storage->update( |
568 | $self->result_source->from, $values, $self->{cond}); |
c01ab172 |
569 | } |
570 | |
87c4e602 |
571 | =head2 update_all |
572 | |
573 | =head3 Arguments: (\%values) |
c01ab172 |
574 | |
a33df5d4 |
575 | Fetches all objects and updates them one at a time. Note that C<update_all> |
576 | will run cascade triggers while L</update> will not. |
c01ab172 |
577 | |
578 | =cut |
579 | |
580 | sub update_all { |
581 | my ($self, $values) = @_; |
701da8c4 |
582 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
c01ab172 |
583 | foreach my $obj ($self->all) { |
584 | $obj->set_columns($values)->update; |
585 | } |
586 | return 1; |
587 | } |
588 | |
bfab575a |
589 | =head2 delete |
ee38fa40 |
590 | |
c01ab172 |
591 | Deletes the contents of the resultset from its result source. |
ee38fa40 |
592 | |
593 | =cut |
594 | |
28927b50 |
595 | sub delete { |
89c0a5a2 |
596 | my ($self) = @_; |
ca4b5ab7 |
597 | my $del = {}; |
598 | $self->throw_exception("Can't delete on resultset with condition unless hash or array") |
599 | unless (ref($self->{cond}) eq 'HASH' || ref($self->{cond}) eq 'ARRAY'); |
600 | if (ref $self->{cond} eq 'ARRAY') { |
601 | $del = [ map { my %hash; |
602 | foreach my $key (keys %{$_}) { |
603 | $key =~ /([^\.]+)$/; |
604 | $hash{$1} = $_->{$key}; |
605 | }; \%hash; } @{$self->{cond}} ]; |
606 | } elsif ((keys %{$self->{cond}})[0] eq '-and') { |
607 | $del->{-and} = [ map { my %hash; |
608 | foreach my $key (keys %{$_}) { |
609 | $key =~ /([^\.]+)$/; |
610 | $hash{$1} = $_->{$key}; |
611 | }; \%hash; } @{$self->{cond}{-and}} ]; |
612 | } else { |
613 | foreach my $key (keys %{$self->{cond}}) { |
614 | $key =~ /([^\.]+)$/; |
615 | $del->{$1} = $self->{cond}{$key}; |
616 | } |
617 | } |
618 | $self->result_source->storage->delete($self->result_source->from, $del); |
89c0a5a2 |
619 | return 1; |
620 | } |
621 | |
c01ab172 |
622 | =head2 delete_all |
623 | |
a33df5d4 |
624 | Fetches all objects and deletes them one at a time. Note that C<delete_all> |
625 | will run cascade triggers while L</delete> will not. |
c01ab172 |
626 | |
627 | =cut |
628 | |
629 | sub delete_all { |
630 | my ($self) = @_; |
631 | $_->delete for $self->all; |
632 | return 1; |
633 | } |
28927b50 |
634 | |
bfab575a |
635 | =head2 pager |
ee38fa40 |
636 | |
637 | Returns a L<Data::Page> object for the current resultset. Only makes |
a33df5d4 |
638 | sense for queries with a C<page> attribute. |
ee38fa40 |
639 | |
640 | =cut |
641 | |
3c5b25c5 |
642 | sub pager { |
643 | my ($self) = @_; |
644 | my $attrs = $self->{attrs}; |
701da8c4 |
645 | $self->throw_exception("Can't create pager for non-paged rs") unless $self->{page}; |
6aeb9185 |
646 | $attrs->{rows} ||= 10; |
647 | $self->count; |
648 | return $self->{pager} ||= Data::Page->new( |
93b004d3 |
649 | $self->{count}, $attrs->{rows}, $self->{page}); |
3c5b25c5 |
650 | } |
651 | |
87c4e602 |
652 | =head2 page |
653 | |
654 | =head3 Arguments: ($page_num) |
ee38fa40 |
655 | |
bfab575a |
656 | Returns a new resultset for the specified page. |
ee38fa40 |
657 | |
658 | =cut |
659 | |
3c5b25c5 |
660 | sub page { |
661 | my ($self, $page) = @_; |
6aeb9185 |
662 | my $attrs = { %{$self->{attrs}} }; |
3c5b25c5 |
663 | $attrs->{page} = $page; |
701da8c4 |
664 | return (ref $self)->new($self->result_source, $attrs); |
fea3d045 |
665 | } |
666 | |
87c4e602 |
667 | =head2 new_result |
668 | |
669 | =head3 Arguments: (\%vals) |
fea3d045 |
670 | |
87f0da6a |
671 | Creates a result in the resultset's result class. |
fea3d045 |
672 | |
673 | =cut |
674 | |
675 | sub new_result { |
676 | my ($self, $values) = @_; |
701da8c4 |
677 | $self->throw_exception( "new_result needs a hash" ) |
fea3d045 |
678 | unless (ref $values eq 'HASH'); |
701da8c4 |
679 | $self->throw_exception( "Can't abstract implicit construct, condition not a hash" ) |
fea3d045 |
680 | if ($self->{cond} && !(ref $self->{cond} eq 'HASH')); |
681 | my %new = %$values; |
682 | my $alias = $self->{attrs}{alias}; |
683 | foreach my $key (keys %{$self->{cond}||{}}) { |
684 | $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:$alias\.)?([^\.]+)$/); |
685 | } |
701da8c4 |
686 | my $obj = $self->result_source->result_class->new(\%new); |
687 | $obj->result_source($self->result_source) if $obj->can('result_source'); |
097d3227 |
688 | $obj; |
fea3d045 |
689 | } |
690 | |
87c4e602 |
691 | =head2 create |
692 | |
693 | =head3 Arguments: (\%vals) |
fea3d045 |
694 | |
87f0da6a |
695 | Inserts a record into the resultset and returns the object. |
fea3d045 |
696 | |
a33df5d4 |
697 | Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. |
fea3d045 |
698 | |
699 | =cut |
700 | |
701 | sub create { |
702 | my ($self, $attrs) = @_; |
701da8c4 |
703 | $self->throw_exception( "create needs a hashref" ) unless ref $attrs eq 'HASH'; |
fea3d045 |
704 | return $self->new_result($attrs)->insert; |
3c5b25c5 |
705 | } |
706 | |
87c4e602 |
707 | =head2 find_or_create |
708 | |
709 | =head3 Arguments: (\%vals, \%attrs?) |
87f0da6a |
710 | |
711 | $class->find_or_create({ key => $val, ... }); |
c2b15ecc |
712 | |
fd9f5466 |
713 | Searches for a record matching the search condition; if it doesn't find one, |
714 | creates one and returns that instead. |
87f0da6a |
715 | |
87f0da6a |
716 | my $cd = $schema->resultset('CD')->find_or_create({ |
717 | cdid => 5, |
718 | artist => 'Massive Attack', |
719 | title => 'Mezzanine', |
720 | year => 2005, |
721 | }); |
722 | |
723 | Also takes an optional C<key> attribute, to search by a specific key or unique |
724 | constraint. For example: |
725 | |
726 | my $cd = $schema->resultset('CD')->find_or_create( |
727 | { |
728 | artist => 'Massive Attack', |
729 | title => 'Mezzanine', |
730 | }, |
731 | { key => 'artist_title' } |
732 | ); |
733 | |
734 | See also L</find> and L</update_or_create>. |
735 | |
c2b15ecc |
736 | =cut |
737 | |
738 | sub find_or_create { |
739 | my $self = shift; |
87f0da6a |
740 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
741 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
742 | my $exists = $self->find($hash, $attrs); |
c2b15ecc |
743 | return defined($exists) ? $exists : $self->create($hash); |
744 | } |
745 | |
87f0da6a |
746 | =head2 update_or_create |
747 | |
748 | $class->update_or_create({ key => $val, ... }); |
749 | |
750 | First, search for an existing row matching one of the unique constraints |
751 | (including the primary key) on the source of this resultset. If a row is |
752 | found, update it with the other given column values. Otherwise, create a new |
753 | row. |
754 | |
755 | Takes an optional C<key> attribute to search on a specific unique constraint. |
756 | For example: |
757 | |
758 | # In your application |
759 | my $cd = $schema->resultset('CD')->update_or_create( |
760 | { |
761 | artist => 'Massive Attack', |
762 | title => 'Mezzanine', |
763 | year => 1998, |
764 | }, |
765 | { key => 'artist_title' } |
766 | ); |
767 | |
768 | If no C<key> is specified, it searches on all unique constraints defined on the |
769 | source, including the primary key. |
770 | |
771 | If the C<key> is specified as C<primary>, search only on the primary key. |
772 | |
a33df5d4 |
773 | See also L</find> and L</find_or_create>. |
774 | |
87f0da6a |
775 | =cut |
776 | |
777 | sub update_or_create { |
778 | my $self = shift; |
779 | |
780 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
781 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
782 | |
701da8c4 |
783 | my %unique_constraints = $self->result_source->unique_constraints; |
87f0da6a |
784 | my @constraint_names = (exists $attrs->{key} |
785 | ? ($attrs->{key}) |
786 | : keys %unique_constraints); |
787 | |
788 | my @unique_hashes; |
789 | foreach my $name (@constraint_names) { |
790 | my @unique_cols = @{ $unique_constraints{$name} }; |
791 | my %unique_hash = |
792 | map { $_ => $hash->{$_} } |
793 | grep { exists $hash->{$_} } |
794 | @unique_cols; |
795 | |
796 | push @unique_hashes, \%unique_hash |
797 | if (scalar keys %unique_hash == scalar @unique_cols); |
798 | } |
799 | |
800 | my $row; |
801 | if (@unique_hashes) { |
802 | $row = $self->search(\@unique_hashes, { rows => 1 })->first; |
803 | if ($row) { |
804 | $row->set_columns($hash); |
805 | $row->update; |
806 | } |
807 | } |
808 | |
809 | unless ($row) { |
810 | $row = $self->create($hash); |
811 | } |
812 | |
813 | return $row; |
814 | } |
815 | |
64acc2bc |
816 | =head2 get_cache |
817 | |
818 | Gets the contents of the cache for the resultset. |
819 | |
820 | =cut |
821 | |
822 | sub get_cache { |
823 | my $self = shift; |
824 | return $self->{all_cache} || []; |
825 | } |
826 | |
827 | =head2 set_cache |
828 | |
829 | Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset. |
830 | |
831 | =cut |
832 | |
833 | sub set_cache { |
834 | my ( $self, $data ) = @_; |
835 | $self->throw_exception("set_cache requires an arrayref") |
836 | if ref $data ne 'ARRAY'; |
837 | my $result_class = $self->result_source->result_class; |
838 | foreach( @$data ) { |
839 | $self->throw_exception("cannot cache object of type '$_', expected '$result_class'") |
840 | if ref $_ ne $result_class; |
841 | } |
842 | $self->{all_cache} = $data; |
843 | } |
844 | |
845 | =head2 clear_cache |
846 | |
847 | Clears the cache for the resultset. |
848 | |
849 | =cut |
850 | |
851 | sub clear_cache { |
852 | my $self = shift; |
853 | $self->set_cache([]); |
854 | } |
855 | |
856 | =head2 related_resultset |
857 | |
858 | Returns a related resultset for the supplied relationship name. |
859 | |
860 | $rs = $rs->related_resultset('foo'); |
861 | |
862 | =cut |
863 | |
864 | sub related_resultset { |
865 | my ( $self, $rel, @rest ) = @_; |
866 | $self->{related_resultsets} ||= {}; |
867 | my $resultsets = $self->{related_resultsets}; |
868 | if( !exists $resultsets->{$rel} ) { |
869 | #warn "fetching related resultset for rel '$rel'"; |
870 | my $rel_obj = $self->result_source->relationship_info($rel); |
871 | $self->throw_exception( |
872 | "search_related: result source '" . $self->result_source->name . |
873 | "' has no such relationship ${rel}") |
874 | unless $rel_obj; #die Dumper $self->{attrs}; |
a86b1efe |
875 | my $rs = $self->search(undef, { join => $rel }); |
876 | #if( $self->{attrs}->{cache} ) { |
877 | # $rs = $self->search(undef); |
878 | #} |
879 | #else { |
880 | #} |
64acc2bc |
881 | #use Data::Dumper; die Dumper $rs->{attrs};#$rs = $self->search( undef ); |
882 | #use Data::Dumper; warn Dumper $self->{attrs}, Dumper $rs->{attrs}; |
883 | my $alias = (defined $rs->{attrs}{seen_join}{$rel} |
884 | && $rs->{attrs}{seen_join}{$rel} > 1 |
885 | ? join('_', $rel, $rs->{attrs}{seen_join}{$rel}) |
886 | : $rel); |
887 | $resultsets->{$rel} = |
888 | $self->result_source->schema->resultset($rel_obj->{class} |
889 | )->search( undef, |
890 | { %{$rs->{attrs}}, |
891 | alias => $alias, |
892 | select => undef(), |
893 | as => undef() } |
894 | )->search(@rest); |
895 | } |
896 | return $resultsets->{$rel}; |
897 | } |
898 | |
701da8c4 |
899 | =head2 throw_exception |
900 | |
901 | See Schema's throw_exception |
902 | |
903 | =cut |
904 | |
905 | sub throw_exception { |
906 | my $self=shift; |
907 | $self->result_source->schema->throw_exception(@_); |
908 | } |
909 | |
40dbc108 |
910 | =head1 ATTRIBUTES |
076652e8 |
911 | |
a33df5d4 |
912 | The resultset takes various attributes that modify its behavior. Here's an |
913 | overview of them: |
bfab575a |
914 | |
915 | =head2 order_by |
076652e8 |
916 | |
a33df5d4 |
917 | Which column(s) to order the results by. This is currently passed through |
918 | directly to SQL, so you can give e.g. C<foo DESC> for a descending order. |
076652e8 |
919 | |
87c4e602 |
920 | =head2 cols |
921 | |
922 | =head3 Arguments: (arrayref) |
976f3686 |
923 | |
a33df5d4 |
924 | Shortcut to request a particular set of columns to be retrieved. Adds |
925 | C<me.> onto the start of any column without a C<.> in it and sets C<select> |
926 | from that, then auto-populates C<as> from C<select> as normal. |
976f3686 |
927 | |
87c4e602 |
928 | =head2 include_columns |
929 | |
930 | =head3 Arguments: (arrayref) |
5ac6a044 |
931 | |
932 | Shortcut to include additional columns in the returned results - for example |
933 | |
934 | { include_columns => ['foo.name'], join => ['foo'] } |
935 | |
936 | would add a 'name' column to the information passed to object inflation |
937 | |
87c4e602 |
938 | =head2 select |
939 | |
940 | =head3 Arguments: (arrayref) |
976f3686 |
941 | |
4a28c340 |
942 | Indicates which columns should be selected from the storage. You can use |
943 | column names, or in the case of RDBMS back ends, function or stored procedure |
944 | names: |
945 | |
946 | $rs = $schema->resultset('Foo')->search( |
947 | {}, |
948 | { |
cf7b40ed |
949 | select => [ |
4a28c340 |
950 | 'column_name', |
951 | { count => 'column_to_count' }, |
952 | { sum => 'column_to_sum' } |
cf7b40ed |
953 | ] |
4a28c340 |
954 | } |
955 | ); |
956 | |
957 | When you use function/stored procedure names and do not supply an C<as> |
958 | attribute, the column names returned are storage-dependent. E.g. MySQL would |
959 | return a column named C<count(column_to_count)> in the above example. |
976f3686 |
960 | |
87c4e602 |
961 | =head2 as |
962 | |
963 | =head3 Arguments: (arrayref) |
076652e8 |
964 | |
4a28c340 |
965 | Indicates column names for object inflation. This is used in conjunction with |
966 | C<select>, usually when C<select> contains one or more function or stored |
967 | procedure names: |
968 | |
969 | $rs = $schema->resultset('Foo')->search( |
970 | {}, |
971 | { |
cf7b40ed |
972 | select => [ |
4a28c340 |
973 | 'column1', |
974 | { count => 'column2' } |
cf7b40ed |
975 | ], |
4a28c340 |
976 | as => [qw/ column1 column2_count /] |
977 | } |
978 | ); |
979 | |
980 | my $foo = $rs->first(); # get the first Foo |
981 | |
982 | If the object against which the search is performed already has an accessor |
983 | matching a column name specified in C<as>, the value can be retrieved using |
984 | the accessor as normal: |
985 | |
986 | my $column1 = $foo->column1(); |
987 | |
988 | If on the other hand an accessor does not exist in the object, you need to |
989 | use C<get_column> instead: |
990 | |
991 | my $column2_count = $foo->get_column('column2_count'); |
992 | |
993 | You can create your own accessors if required - see |
994 | L<DBIx::Class::Manual::Cookbook> for details. |
ee38fa40 |
995 | |
bfab575a |
996 | =head2 join |
ee38fa40 |
997 | |
a33df5d4 |
998 | Contains a list of relationships that should be joined for this query. For |
999 | example: |
1000 | |
1001 | # Get CDs by Nine Inch Nails |
1002 | my $rs = $schema->resultset('CD')->search( |
1003 | { 'artist.name' => 'Nine Inch Nails' }, |
1004 | { join => 'artist' } |
1005 | ); |
1006 | |
1007 | Can also contain a hash reference to refer to the other relation's relations. |
1008 | For example: |
1009 | |
1010 | package MyApp::Schema::Track; |
1011 | use base qw/DBIx::Class/; |
1012 | __PACKAGE__->table('track'); |
1013 | __PACKAGE__->add_columns(qw/trackid cd position title/); |
1014 | __PACKAGE__->set_primary_key('trackid'); |
1015 | __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD'); |
1016 | 1; |
1017 | |
1018 | # In your application |
1019 | my $rs = $schema->resultset('Artist')->search( |
1020 | { 'track.title' => 'Teardrop' }, |
1021 | { |
1022 | join => { cd => 'track' }, |
1023 | order_by => 'artist.name', |
1024 | } |
1025 | ); |
1026 | |
2cb360cc |
1027 | If the same join is supplied twice, it will be aliased to <rel>_2 (and |
1028 | similarly for a third time). For e.g. |
1029 | |
1030 | my $rs = $schema->resultset('Artist')->search( |
1031 | { 'cds.title' => 'Foo', |
1032 | 'cds_2.title' => 'Bar' }, |
1033 | { join => [ qw/cds cds/ ] }); |
1034 | |
1035 | will return a set of all artists that have both a cd with title Foo and a cd |
1036 | with title Bar. |
1037 | |
1038 | If you want to fetch related objects from other tables as well, see C<prefetch> |
ae1c90a1 |
1039 | below. |
ee38fa40 |
1040 | |
87c4e602 |
1041 | =head2 prefetch |
1042 | |
1043 | =head3 Arguments: arrayref/hashref |
ee38fa40 |
1044 | |
ae1c90a1 |
1045 | Contains one or more relationships that should be fetched along with the main |
bfab575a |
1046 | query (when they are accessed afterwards they will have already been |
a33df5d4 |
1047 | "prefetched"). This is useful for when you know you will need the related |
ae1c90a1 |
1048 | objects, because it saves at least one query: |
1049 | |
1050 | my $rs = $schema->resultset('Tag')->search( |
1051 | {}, |
1052 | { |
1053 | prefetch => { |
1054 | cd => 'artist' |
1055 | } |
1056 | } |
1057 | ); |
1058 | |
1059 | The initial search results in SQL like the following: |
1060 | |
1061 | SELECT tag.*, cd.*, artist.* FROM tag |
1062 | JOIN cd ON tag.cd = cd.cdid |
1063 | JOIN artist ON cd.artist = artist.artistid |
1064 | |
1065 | L<DBIx::Class> has no need to go back to the database when we access the |
1066 | C<cd> or C<artist> relationships, which saves us two SQL statements in this |
1067 | case. |
1068 | |
2cb360cc |
1069 | Simple prefetches will be joined automatically, so there is no need |
1070 | for a C<join> attribute in the above search. If you're prefetching to |
1071 | depth (e.g. { cd => { artist => 'label' } or similar), you'll need to |
1072 | specify the join as well. |
ae1c90a1 |
1073 | |
1074 | C<prefetch> can be used with the following relationship types: C<belongs_to>, |
2cb360cc |
1075 | C<has_one> (or if you're using C<add_relationship>, any relationship declared |
1076 | with an accessor type of 'single' or 'filter'). |
ee38fa40 |
1077 | |
87c4e602 |
1078 | =head2 from |
1079 | |
1080 | =head3 Arguments: (arrayref) |
ee38fa40 |
1081 | |
4a28c340 |
1082 | The C<from> attribute gives you manual control over the C<FROM> clause of SQL |
1083 | statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN> |
1084 | clauses. |
ee38fa40 |
1085 | |
a33df5d4 |
1086 | NOTE: Use this on your own risk. This allows you to shoot off your foot! |
4a28c340 |
1087 | C<join> will usually do what you need and it is strongly recommended that you |
1088 | avoid using C<from> unless you cannot achieve the desired result using C<join>. |
1089 | |
1090 | In simple terms, C<from> works as follows: |
1091 | |
1092 | [ |
1093 | { <alias> => <table>, -join-type => 'inner|left|right' } |
1094 | [] # nested JOIN (optional) |
1095 | { <table.column> = <foreign_table.foreign_key> } |
1096 | ] |
1097 | |
1098 | JOIN |
1099 | <alias> <table> |
1100 | [JOIN ...] |
1101 | ON <table.column> = <foreign_table.foreign_key> |
1102 | |
1103 | An easy way to follow the examples below is to remember the following: |
1104 | |
1105 | Anything inside "[]" is a JOIN |
1106 | Anything inside "{}" is a condition for the enclosing JOIN |
1107 | |
1108 | The following examples utilize a "person" table in a family tree application. |
1109 | In order to express parent->child relationships, this table is self-joined: |
1110 | |
1111 | # Person->belongs_to('father' => 'Person'); |
1112 | # Person->belongs_to('mother' => 'Person'); |
1113 | |
1114 | C<from> can be used to nest joins. Here we return all children with a father, |
1115 | then search against all mothers of those children: |
1116 | |
1117 | $rs = $schema->resultset('Person')->search( |
1118 | {}, |
1119 | { |
1120 | alias => 'mother', # alias columns in accordance with "from" |
1121 | from => [ |
1122 | { mother => 'person' }, |
1123 | [ |
1124 | [ |
1125 | { child => 'person' }, |
1126 | [ |
1127 | { father => 'person' }, |
1128 | { 'father.person_id' => 'child.father_id' } |
1129 | ] |
1130 | ], |
1131 | { 'mother.person_id' => 'child.mother_id' } |
fd9f5466 |
1132 | ], |
4a28c340 |
1133 | ] |
1134 | }, |
1135 | ); |
1136 | |
1137 | # Equivalent SQL: |
1138 | # SELECT mother.* FROM person mother |
1139 | # JOIN ( |
1140 | # person child |
1141 | # JOIN person father |
1142 | # ON ( father.person_id = child.father_id ) |
1143 | # ) |
1144 | # ON ( mother.person_id = child.mother_id ) |
1145 | |
1146 | The type of any join can be controlled manually. To search against only people |
1147 | with a father in the person table, we could explicitly use C<INNER JOIN>: |
1148 | |
1149 | $rs = $schema->resultset('Person')->search( |
1150 | {}, |
1151 | { |
1152 | alias => 'child', # alias columns in accordance with "from" |
1153 | from => [ |
1154 | { child => 'person' }, |
1155 | [ |
1156 | { father => 'person', -join-type => 'inner' }, |
1157 | { 'father.id' => 'child.father_id' } |
1158 | ], |
1159 | ] |
1160 | }, |
1161 | ); |
1162 | |
1163 | # Equivalent SQL: |
1164 | # SELECT child.* FROM person child |
1165 | # INNER JOIN person father ON child.father_id = father.id |
ee38fa40 |
1166 | |
bfab575a |
1167 | =head2 page |
076652e8 |
1168 | |
a33df5d4 |
1169 | For a paged resultset, specifies which page to retrieve. Leave unset |
bfab575a |
1170 | for an unpaged resultset. |
076652e8 |
1171 | |
bfab575a |
1172 | =head2 rows |
076652e8 |
1173 | |
4a28c340 |
1174 | For a paged resultset, how many rows per page: |
1175 | |
1176 | rows => 10 |
1177 | |
1178 | Can also be used to simulate an SQL C<LIMIT>. |
076652e8 |
1179 | |
87c4e602 |
1180 | =head2 group_by |
1181 | |
1182 | =head3 Arguments: (arrayref) |
54540863 |
1183 | |
bda4c2b8 |
1184 | A arrayref of columns to group by. Can include columns of joined tables. |
54540863 |
1185 | |
675ce4a6 |
1186 | group_by => [qw/ column1 column2 ... /] |
1187 | |
54540863 |
1188 | =head2 distinct |
1189 | |
a33df5d4 |
1190 | Set to 1 to group by all columns. |
1191 | |
1192 | For more examples of using these attributes, see |
1193 | L<DBIx::Class::Manual::Cookbook>. |
54540863 |
1194 | |
bfab575a |
1195 | =cut |
076652e8 |
1196 | |
89c0a5a2 |
1197 | 1; |