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 |
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 | |
ff7bb7a1 |
158 | my $rs; |
159 | if( @_ ) { |
160 | |
161 | my $attrs = { %{$self->{attrs}} }; |
8839560b |
162 | my $having = delete $attrs->{having}; |
ff7bb7a1 |
163 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
164 | $attrs = { %$attrs, %{ pop(@_) } }; |
165 | } |
6009260a |
166 | |
3e0e9e27 |
167 | my $where = (@_ |
168 | ? ((@_ == 1 || ref $_[0] eq "HASH") |
169 | ? shift |
170 | : ((@_ % 2) |
171 | ? $self->throw_exception( |
172 | "Odd number of arguments to search") |
173 | : {@_})) |
174 | : undef()); |
ff7bb7a1 |
175 | if (defined $where) { |
176 | $where = (defined $attrs->{where} |
ad3d2d7c |
177 | ? { '-and' => |
178 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
179 | $where, $attrs->{where} ] } |
0a3c5b43 |
180 | : $where); |
ff7bb7a1 |
181 | $attrs->{where} = $where; |
182 | } |
0a3c5b43 |
183 | |
8839560b |
184 | if (defined $having) { |
185 | $having = (defined $attrs->{having} |
186 | ? { '-and' => |
187 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
188 | $having, $attrs->{having} ] } |
189 | : $having); |
190 | $attrs->{having} = $having; |
191 | } |
192 | |
ff7bb7a1 |
193 | $rs = (ref $self)->new($self->result_source, $attrs); |
194 | } |
195 | else { |
196 | $rs = $self; |
197 | $rs->reset(); |
198 | } |
0a3c5b43 |
199 | return (wantarray ? $rs->all : $rs); |
200 | } |
201 | |
87f0da6a |
202 | =head2 search_literal |
203 | |
6009260a |
204 | my @obj = $rs->search_literal($literal_where_cond, @bind); |
205 | my $new_rs = $rs->search_literal($literal_where_cond, @bind); |
206 | |
207 | Pass a literal chunk of SQL to be added to the conditional part of the |
87f0da6a |
208 | resultset. |
6009260a |
209 | |
bfab575a |
210 | =cut |
211 | |
6009260a |
212 | sub search_literal { |
213 | my ($self, $cond, @vals) = @_; |
214 | my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {}); |
215 | $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ]; |
216 | return $self->search(\$cond, $attrs); |
217 | } |
0a3c5b43 |
218 | |
87c4e602 |
219 | =head2 find |
220 | |
221 | =head3 Arguments: (@colvalues) | (\%cols, \%attrs?) |
87f0da6a |
222 | |
223 | Finds a row based on its primary key or unique constraint. For example: |
224 | |
87f0da6a |
225 | my $cd = $schema->resultset('CD')->find(5); |
226 | |
227 | Also takes an optional C<key> attribute, to search by a specific key or unique |
228 | constraint. For example: |
229 | |
230 | my $cd = $schema->resultset('CD')->find_or_create( |
231 | { |
232 | artist => 'Massive Attack', |
233 | title => 'Mezzanine', |
234 | }, |
235 | { key => 'artist_title' } |
236 | ); |
237 | |
a33df5d4 |
238 | See also L</find_or_create> and L</update_or_create>. |
239 | |
87f0da6a |
240 | =cut |
716b3d29 |
241 | |
242 | sub find { |
243 | my ($self, @vals) = @_; |
244 | my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {}); |
87f0da6a |
245 | |
701da8c4 |
246 | my @cols = $self->result_source->primary_columns; |
87f0da6a |
247 | if (exists $attrs->{key}) { |
701da8c4 |
248 | my %uniq = $self->result_source->unique_constraints; |
87f0da6a |
249 | $self->( "Unknown key " . $attrs->{key} . " on " . $self->name ) |
250 | unless exists $uniq{$attrs->{key}}; |
251 | @cols = @{ $uniq{$attrs->{key}} }; |
252 | } |
253 | #use Data::Dumper; warn Dumper($attrs, @vals, @cols); |
701da8c4 |
254 | $self->throw_exception( "Can't find unless a primary key or unique constraint is defined" ) |
87f0da6a |
255 | unless @cols; |
256 | |
716b3d29 |
257 | my $query; |
258 | if (ref $vals[0] eq 'HASH') { |
01bc091e |
259 | $query = { %{$vals[0]} }; |
87f0da6a |
260 | } elsif (@cols == @vals) { |
716b3d29 |
261 | $query = {}; |
87f0da6a |
262 | @{$query}{@cols} = @vals; |
716b3d29 |
263 | } else { |
264 | $query = {@vals}; |
265 | } |
01bc091e |
266 | foreach (keys %$query) { |
267 | next if m/\./; |
268 | $query->{$self->{attrs}{alias}.'.'.$_} = delete $query->{$_}; |
269 | } |
716b3d29 |
270 | #warn Dumper($query); |
a04ab285 |
271 | return (keys %$attrs |
272 | ? $self->search($query,$attrs)->single |
273 | : $self->single($query)); |
716b3d29 |
274 | } |
275 | |
b52e9bf8 |
276 | =head2 search_related |
277 | |
278 | $rs->search_related('relname', $cond?, $attrs?); |
279 | |
a33df5d4 |
280 | Search the specified relationship. Optionally specify a condition for matching |
281 | records. |
282 | |
b52e9bf8 |
283 | =cut |
284 | |
6aeb9185 |
285 | sub search_related { |
64acc2bc |
286 | return shift->related_resultset(shift)->search(@_); |
6aeb9185 |
287 | } |
b52e9bf8 |
288 | |
bfab575a |
289 | =head2 cursor |
ee38fa40 |
290 | |
bfab575a |
291 | Returns a storage-driven cursor to the given resultset. |
ee38fa40 |
292 | |
293 | =cut |
294 | |
73f58123 |
295 | sub cursor { |
296 | my ($self) = @_; |
701da8c4 |
297 | my ($attrs) = $self->{attrs}; |
6aeb9185 |
298 | $attrs = { %$attrs }; |
73f58123 |
299 | return $self->{cursor} |
701da8c4 |
300 | ||= $self->result_source->storage->select($self->{from}, $attrs->{select}, |
73f58123 |
301 | $attrs->{where},$attrs); |
302 | } |
303 | |
a04ab285 |
304 | =head2 single |
305 | |
306 | Inflates the first result without creating a cursor |
307 | |
308 | =cut |
309 | |
310 | sub single { |
311 | my ($self, $extra) = @_; |
312 | my ($attrs) = $self->{attrs}; |
313 | $attrs = { %$attrs }; |
314 | if ($extra) { |
315 | if (defined $attrs->{where}) { |
316 | $attrs->{where} = { |
317 | '-and' |
318 | => [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
319 | delete $attrs->{where}, $extra ] |
320 | }; |
321 | } else { |
322 | $attrs->{where} = $extra; |
323 | } |
324 | } |
325 | my @data = $self->result_source->storage->select_single( |
326 | $self->{from}, $attrs->{select}, |
327 | $attrs->{where},$attrs); |
328 | return (@data ? $self->_construct_object(@data) : ()); |
329 | } |
330 | |
331 | |
87f0da6a |
332 | =head2 search_like |
333 | |
a33df5d4 |
334 | Perform a search, but use C<LIKE> instead of equality as the condition. Note |
335 | that this is simply a convenience method; you most likely want to use |
336 | L</search> with specific operators. |
337 | |
338 | For more information, see L<DBIx::Class::Manual::Cookbook>. |
87f0da6a |
339 | |
340 | =cut |
58a4bd18 |
341 | |
342 | sub search_like { |
343 | my $class = shift; |
344 | my $attrs = { }; |
345 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
346 | $attrs = pop(@_); |
347 | } |
348 | my $query = ref $_[0] eq "HASH" ? { %{shift()} }: {@_}; |
349 | $query->{$_} = { 'like' => $query->{$_} } for keys %$query; |
350 | return $class->search($query, { %$attrs }); |
351 | } |
352 | |
87c4e602 |
353 | =head2 slice |
354 | |
355 | =head3 Arguments: ($first, $last) |
ee38fa40 |
356 | |
bfab575a |
357 | Returns a subset of elements from the resultset. |
ee38fa40 |
358 | |
359 | =cut |
360 | |
89c0a5a2 |
361 | sub slice { |
362 | my ($self, $min, $max) = @_; |
363 | my $attrs = { %{ $self->{attrs} || {} } }; |
6aeb9185 |
364 | $attrs->{offset} ||= 0; |
365 | $attrs->{offset} += $min; |
89c0a5a2 |
366 | $attrs->{rows} = ($max ? ($max - $min + 1) : 1); |
701da8c4 |
367 | my $slice = (ref $self)->new($self->result_source, $attrs); |
89c0a5a2 |
368 | return (wantarray ? $slice->all : $slice); |
369 | } |
370 | |
87f0da6a |
371 | =head2 next |
ee38fa40 |
372 | |
a33df5d4 |
373 | Returns the next element in the resultset (C<undef> is there is none). |
374 | |
375 | Can be used to efficiently iterate over records in the resultset: |
376 | |
377 | my $rs = $schema->resultset('CD')->search({}); |
378 | while (my $cd = $rs->next) { |
379 | print $cd->title; |
380 | } |
ee38fa40 |
381 | |
382 | =cut |
383 | |
89c0a5a2 |
384 | sub next { |
385 | my ($self) = @_; |
3e0e9e27 |
386 | my $cache; |
387 | if( @{$cache = $self->{all_cache} || []}) { |
64acc2bc |
388 | $self->{all_cache_position} ||= 0; |
389 | my $obj = $cache->[$self->{all_cache_position}]; |
390 | $self->{all_cache_position}++; |
391 | return $obj; |
392 | } |
3e0e9e27 |
393 | if ($self->{attrs}{cache}) { |
394 | $self->{all_cache_position} = 0; |
395 | return ($self->all)[0]; |
396 | } |
73f58123 |
397 | my @row = $self->cursor->next; |
a953d8d9 |
398 | # warn Dumper(\@row); use Data::Dumper; |
89c0a5a2 |
399 | return unless (@row); |
c7ce65e6 |
400 | return $self->_construct_object(@row); |
401 | } |
402 | |
403 | sub _construct_object { |
404 | my ($self, @row) = @_; |
64acc2bc |
405 | my @row_orig = @row; # copy @row for key comparison later, because @row will change |
b3e8ac9b |
406 | my @as = @{ $self->{attrs}{as} }; |
f9cc31dd |
407 | #use Data::Dumper; warn Dumper \@as; |
976f3686 |
408 | #warn "@cols -> @row"; |
b3e8ac9b |
409 | my $info = [ {}, {} ]; |
410 | foreach my $as (@as) { |
64acc2bc |
411 | my $rs = $self; |
b3e8ac9b |
412 | my $target = $info; |
413 | my @parts = split(/\./, $as); |
414 | my $col = pop(@parts); |
415 | foreach my $p (@parts) { |
416 | $target = $target->[1]->{$p} ||= []; |
64acc2bc |
417 | |
f9cc31dd |
418 | $rs = $rs->related_resultset($p) if $rs->{attrs}->{cache}; |
c7ce65e6 |
419 | } |
f9cc31dd |
420 | |
64acc2bc |
421 | $target->[0]->{$col} = shift @row |
422 | if ref($target->[0]) ne 'ARRAY'; # arrayref is pre-inflated objects, do not overwrite |
c7ce65e6 |
423 | } |
b3e8ac9b |
424 | #use Data::Dumper; warn Dumper(\@as, $info); |
701da8c4 |
425 | my $new = $self->result_source->result_class->inflate_result( |
426 | $self->result_source, @$info); |
33ce49d6 |
427 | $new = $self->{attrs}{record_filter}->($new) |
428 | if exists $self->{attrs}{record_filter}; |
f9cc31dd |
429 | |
430 | if( $self->{attrs}->{cache} ) { |
431 | while( my( $rel, $rs ) = each( %{$self->{related_resultsets}} ) ) { |
432 | $rs->all; |
433 | #warn "$rel:", @{$rs->get_cache}; |
434 | } |
435 | $self->build_rr( $self, $new ); |
436 | } |
437 | |
33ce49d6 |
438 | return $new; |
89c0a5a2 |
439 | } |
f9cc31dd |
440 | |
441 | sub build_rr { |
442 | # build related resultsets for supplied object |
443 | my ( $self, $context, $obj ) = @_; |
444 | |
445 | my $re = qr/^\w+\./; |
446 | while( my ($rel, $rs) = each( %{$context->{related_resultsets}} ) ) { |
447 | #warn "context:", $context->result_source->name, ", rel:$rel, rs:", $rs->result_source->name; |
448 | my @objs = (); |
449 | my $map = {}; |
450 | my $cond = $context->result_source->relationship_info($rel)->{cond}; |
451 | keys %$cond; |
452 | while( my( $rel_key, $pk ) = each(%$cond) ) { |
453 | $rel_key =~ s/$re//; |
454 | $pk =~ s/$re//; |
455 | $map->{$rel_key} = $pk; |
456 | } |
457 | |
458 | $rs->reset(); |
459 | while( my $rel_obj = $rs->next ) { |
460 | while( my( $rel_key, $pk ) = each(%$map) ) { |
461 | if( $rel_obj->get_column($rel_key) eq $obj->get_column($pk) ) { |
462 | push @objs, $rel_obj; |
463 | } |
464 | } |
465 | } |
466 | |
467 | my $rel_rs = $obj->related_resultset($rel); |
468 | $rel_rs->{attrs}->{cache} = 1; |
469 | $rel_rs->set_cache( \@objs ); |
470 | |
471 | while( my $rel_obj = $rel_rs->next ) { |
472 | $self->build_rr( $rs, $rel_obj ); |
473 | } |
474 | |
475 | } |
476 | |
477 | } |
89c0a5a2 |
478 | |
87c4e602 |
479 | =head2 result_source |
701da8c4 |
480 | |
481 | Returns a reference to the result source for this recordset. |
482 | |
483 | =cut |
484 | |
485 | |
bfab575a |
486 | =head2 count |
ee38fa40 |
487 | |
bfab575a |
488 | Performs an SQL C<COUNT> with the same query as the resultset was built |
6009260a |
489 | with to find the number of elements. If passed arguments, does a search |
490 | on the resultset and counts the results of that. |
ee38fa40 |
491 | |
bda4c2b8 |
492 | Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY> |
493 | using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do |
494 | not support C<DISTINCT> with multiple columns. If you are using such a |
495 | database, you should only use columns from the main table in your C<group_by> |
496 | clause. |
497 | |
ee38fa40 |
498 | =cut |
499 | |
89c0a5a2 |
500 | sub count { |
6009260a |
501 | my $self = shift; |
502 | return $self->search(@_)->count if @_ && defined $_[0]; |
6aeb9185 |
503 | unless (defined $self->{count}) { |
64acc2bc |
504 | return scalar @{ $self->get_cache } |
505 | if @{ $self->get_cache }; |
15c382be |
506 | my $group_by; |
507 | my $select = { 'count' => '*' }; |
8839560b |
508 | my $attrs = { %{ $self->{attrs} } }; |
509 | if( $group_by = delete $attrs->{group_by} ) { |
510 | delete $attrs->{having}; |
dec2517f |
511 | my @distinct = (ref $group_by ? @$group_by : ($group_by)); |
15c382be |
512 | # todo: try CONCAT for multi-column pk |
513 | my @pk = $self->result_source->primary_columns; |
514 | if( scalar(@pk) == 1 ) { |
515 | my $pk = shift(@pk); |
8839560b |
516 | my $alias = $attrs->{alias}; |
15c382be |
517 | my $re = qr/^($alias\.)?$pk$/; |
d0f1e63f |
518 | foreach my $column ( @distinct) { |
15c382be |
519 | if( $column =~ $re ) { |
520 | @distinct = ( $column ); |
521 | last; |
522 | } |
523 | } |
524 | } |
525 | |
526 | $select = { count => { 'distinct' => \@distinct } }; |
527 | #use Data::Dumper; die Dumper $select; |
528 | } |
529 | |
8839560b |
530 | $attrs->{select} = $select; |
531 | $attrs->{as} = [ 'count' ]; |
ea20d0fd |
532 | # offset, order by and page are not needed to count. record_filter is cdbi |
533 | delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/; |
3c5b25c5 |
534 | |
701da8c4 |
535 | ($self->{count}) = (ref $self)->new($self->result_source, $attrs)->cursor->next; |
3c5b25c5 |
536 | } |
537 | return 0 unless $self->{count}; |
6aeb9185 |
538 | my $count = $self->{count}; |
539 | $count -= $self->{attrs}{offset} if $self->{attrs}{offset}; |
540 | $count = $self->{attrs}{rows} if |
541 | ($self->{attrs}{rows} && $self->{attrs}{rows} < $count); |
542 | return $count; |
89c0a5a2 |
543 | } |
544 | |
bfab575a |
545 | =head2 count_literal |
6009260a |
546 | |
a33df5d4 |
547 | Calls L</search_literal> with the passed arguments, then L</count>. |
6009260a |
548 | |
549 | =cut |
550 | |
551 | sub count_literal { shift->search_literal(@_)->count; } |
552 | |
bfab575a |
553 | =head2 all |
ee38fa40 |
554 | |
bfab575a |
555 | Returns all elements in the resultset. Called implictly if the resultset |
556 | is returned in list context. |
ee38fa40 |
557 | |
558 | =cut |
559 | |
89c0a5a2 |
560 | sub all { |
561 | my ($self) = @_; |
64acc2bc |
562 | return @{ $self->get_cache } |
563 | if @{ $self->get_cache }; |
564 | if( $self->{attrs}->{cache} ) { |
565 | my @obj = map { $self->_construct_object(@$_); } |
566 | $self->cursor->all; |
567 | $self->set_cache( \@obj ); |
3e0e9e27 |
568 | return @obj; |
64acc2bc |
569 | } |
c7ce65e6 |
570 | return map { $self->_construct_object(@$_); } |
73f58123 |
571 | $self->cursor->all; |
89c0a5a2 |
572 | } |
573 | |
bfab575a |
574 | =head2 reset |
ee38fa40 |
575 | |
bfab575a |
576 | Resets the resultset's cursor, so you can iterate through the elements again. |
ee38fa40 |
577 | |
578 | =cut |
579 | |
89c0a5a2 |
580 | sub reset { |
581 | my ($self) = @_; |
64acc2bc |
582 | $self->{all_cache_position} = 0; |
73f58123 |
583 | $self->cursor->reset; |
89c0a5a2 |
584 | return $self; |
585 | } |
586 | |
bfab575a |
587 | =head2 first |
ee38fa40 |
588 | |
bfab575a |
589 | Resets the resultset and returns the first element. |
ee38fa40 |
590 | |
591 | =cut |
592 | |
89c0a5a2 |
593 | sub first { |
594 | return $_[0]->reset->next; |
595 | } |
596 | |
87c4e602 |
597 | =head2 update |
598 | |
599 | =head3 Arguments: (\%values) |
c01ab172 |
600 | |
a33df5d4 |
601 | Sets the specified columns in the resultset to the supplied values. |
c01ab172 |
602 | |
603 | =cut |
604 | |
605 | sub update { |
606 | my ($self, $values) = @_; |
701da8c4 |
607 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
608 | return $self->result_source->storage->update( |
609 | $self->result_source->from, $values, $self->{cond}); |
c01ab172 |
610 | } |
611 | |
87c4e602 |
612 | =head2 update_all |
613 | |
614 | =head3 Arguments: (\%values) |
c01ab172 |
615 | |
a33df5d4 |
616 | Fetches all objects and updates them one at a time. Note that C<update_all> |
617 | will run cascade triggers while L</update> will not. |
c01ab172 |
618 | |
619 | =cut |
620 | |
621 | sub update_all { |
622 | my ($self, $values) = @_; |
701da8c4 |
623 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
c01ab172 |
624 | foreach my $obj ($self->all) { |
625 | $obj->set_columns($values)->update; |
626 | } |
627 | return 1; |
628 | } |
629 | |
bfab575a |
630 | =head2 delete |
ee38fa40 |
631 | |
c01ab172 |
632 | Deletes the contents of the resultset from its result source. |
ee38fa40 |
633 | |
634 | =cut |
635 | |
28927b50 |
636 | sub delete { |
89c0a5a2 |
637 | my ($self) = @_; |
ca4b5ab7 |
638 | my $del = {}; |
639 | $self->throw_exception("Can't delete on resultset with condition unless hash or array") |
640 | unless (ref($self->{cond}) eq 'HASH' || ref($self->{cond}) eq 'ARRAY'); |
641 | if (ref $self->{cond} eq 'ARRAY') { |
642 | $del = [ map { my %hash; |
643 | foreach my $key (keys %{$_}) { |
644 | $key =~ /([^\.]+)$/; |
645 | $hash{$1} = $_->{$key}; |
646 | }; \%hash; } @{$self->{cond}} ]; |
647 | } elsif ((keys %{$self->{cond}})[0] eq '-and') { |
648 | $del->{-and} = [ map { my %hash; |
649 | foreach my $key (keys %{$_}) { |
650 | $key =~ /([^\.]+)$/; |
651 | $hash{$1} = $_->{$key}; |
652 | }; \%hash; } @{$self->{cond}{-and}} ]; |
653 | } else { |
654 | foreach my $key (keys %{$self->{cond}}) { |
655 | $key =~ /([^\.]+)$/; |
656 | $del->{$1} = $self->{cond}{$key}; |
657 | } |
658 | } |
659 | $self->result_source->storage->delete($self->result_source->from, $del); |
89c0a5a2 |
660 | return 1; |
661 | } |
662 | |
c01ab172 |
663 | =head2 delete_all |
664 | |
a33df5d4 |
665 | Fetches all objects and deletes them one at a time. Note that C<delete_all> |
666 | will run cascade triggers while L</delete> will not. |
c01ab172 |
667 | |
668 | =cut |
669 | |
670 | sub delete_all { |
671 | my ($self) = @_; |
672 | $_->delete for $self->all; |
673 | return 1; |
674 | } |
28927b50 |
675 | |
bfab575a |
676 | =head2 pager |
ee38fa40 |
677 | |
678 | Returns a L<Data::Page> object for the current resultset. Only makes |
a33df5d4 |
679 | sense for queries with a C<page> attribute. |
ee38fa40 |
680 | |
681 | =cut |
682 | |
3c5b25c5 |
683 | sub pager { |
684 | my ($self) = @_; |
685 | my $attrs = $self->{attrs}; |
701da8c4 |
686 | $self->throw_exception("Can't create pager for non-paged rs") unless $self->{page}; |
6aeb9185 |
687 | $attrs->{rows} ||= 10; |
688 | $self->count; |
689 | return $self->{pager} ||= Data::Page->new( |
93b004d3 |
690 | $self->{count}, $attrs->{rows}, $self->{page}); |
3c5b25c5 |
691 | } |
692 | |
87c4e602 |
693 | =head2 page |
694 | |
695 | =head3 Arguments: ($page_num) |
ee38fa40 |
696 | |
bfab575a |
697 | Returns a new resultset for the specified page. |
ee38fa40 |
698 | |
699 | =cut |
700 | |
3c5b25c5 |
701 | sub page { |
702 | my ($self, $page) = @_; |
6aeb9185 |
703 | my $attrs = { %{$self->{attrs}} }; |
3c5b25c5 |
704 | $attrs->{page} = $page; |
701da8c4 |
705 | return (ref $self)->new($self->result_source, $attrs); |
fea3d045 |
706 | } |
707 | |
87c4e602 |
708 | =head2 new_result |
709 | |
710 | =head3 Arguments: (\%vals) |
fea3d045 |
711 | |
87f0da6a |
712 | Creates a result in the resultset's result class. |
fea3d045 |
713 | |
714 | =cut |
715 | |
716 | sub new_result { |
717 | my ($self, $values) = @_; |
701da8c4 |
718 | $self->throw_exception( "new_result needs a hash" ) |
fea3d045 |
719 | unless (ref $values eq 'HASH'); |
701da8c4 |
720 | $self->throw_exception( "Can't abstract implicit construct, condition not a hash" ) |
fea3d045 |
721 | if ($self->{cond} && !(ref $self->{cond} eq 'HASH')); |
722 | my %new = %$values; |
723 | my $alias = $self->{attrs}{alias}; |
724 | foreach my $key (keys %{$self->{cond}||{}}) { |
725 | $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:$alias\.)?([^\.]+)$/); |
726 | } |
701da8c4 |
727 | my $obj = $self->result_source->result_class->new(\%new); |
728 | $obj->result_source($self->result_source) if $obj->can('result_source'); |
097d3227 |
729 | $obj; |
fea3d045 |
730 | } |
731 | |
87c4e602 |
732 | =head2 create |
733 | |
734 | =head3 Arguments: (\%vals) |
fea3d045 |
735 | |
87f0da6a |
736 | Inserts a record into the resultset and returns the object. |
fea3d045 |
737 | |
a33df5d4 |
738 | Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. |
fea3d045 |
739 | |
740 | =cut |
741 | |
742 | sub create { |
743 | my ($self, $attrs) = @_; |
701da8c4 |
744 | $self->throw_exception( "create needs a hashref" ) unless ref $attrs eq 'HASH'; |
fea3d045 |
745 | return $self->new_result($attrs)->insert; |
3c5b25c5 |
746 | } |
747 | |
87c4e602 |
748 | =head2 find_or_create |
749 | |
750 | =head3 Arguments: (\%vals, \%attrs?) |
87f0da6a |
751 | |
752 | $class->find_or_create({ key => $val, ... }); |
c2b15ecc |
753 | |
c2b15ecc |
754 | Searches for a record matching the search condition; if it doesn't find one, |
cf7b40ed |
755 | creates one and returns that instead. |
87f0da6a |
756 | |
87f0da6a |
757 | my $cd = $schema->resultset('CD')->find_or_create({ |
758 | cdid => 5, |
759 | artist => 'Massive Attack', |
760 | title => 'Mezzanine', |
761 | year => 2005, |
762 | }); |
763 | |
764 | Also takes an optional C<key> attribute, to search by a specific key or unique |
765 | constraint. For example: |
766 | |
767 | my $cd = $schema->resultset('CD')->find_or_create( |
768 | { |
769 | artist => 'Massive Attack', |
770 | title => 'Mezzanine', |
771 | }, |
772 | { key => 'artist_title' } |
773 | ); |
774 | |
775 | See also L</find> and L</update_or_create>. |
776 | |
c2b15ecc |
777 | =cut |
778 | |
779 | sub find_or_create { |
780 | my $self = shift; |
87f0da6a |
781 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
782 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
783 | my $exists = $self->find($hash, $attrs); |
c2b15ecc |
784 | return defined($exists) ? $exists : $self->create($hash); |
785 | } |
786 | |
87f0da6a |
787 | =head2 update_or_create |
788 | |
789 | $class->update_or_create({ key => $val, ... }); |
790 | |
791 | First, search for an existing row matching one of the unique constraints |
792 | (including the primary key) on the source of this resultset. If a row is |
793 | found, update it with the other given column values. Otherwise, create a new |
794 | row. |
795 | |
796 | Takes an optional C<key> attribute to search on a specific unique constraint. |
797 | For example: |
798 | |
799 | # In your application |
800 | my $cd = $schema->resultset('CD')->update_or_create( |
801 | { |
802 | artist => 'Massive Attack', |
803 | title => 'Mezzanine', |
804 | year => 1998, |
805 | }, |
806 | { key => 'artist_title' } |
807 | ); |
808 | |
809 | If no C<key> is specified, it searches on all unique constraints defined on the |
810 | source, including the primary key. |
811 | |
812 | If the C<key> is specified as C<primary>, search only on the primary key. |
813 | |
a33df5d4 |
814 | See also L</find> and L</find_or_create>. |
815 | |
87f0da6a |
816 | =cut |
817 | |
818 | sub update_or_create { |
819 | my $self = shift; |
820 | |
821 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
822 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
823 | |
701da8c4 |
824 | my %unique_constraints = $self->result_source->unique_constraints; |
87f0da6a |
825 | my @constraint_names = (exists $attrs->{key} |
826 | ? ($attrs->{key}) |
827 | : keys %unique_constraints); |
828 | |
829 | my @unique_hashes; |
830 | foreach my $name (@constraint_names) { |
831 | my @unique_cols = @{ $unique_constraints{$name} }; |
832 | my %unique_hash = |
833 | map { $_ => $hash->{$_} } |
834 | grep { exists $hash->{$_} } |
835 | @unique_cols; |
836 | |
837 | push @unique_hashes, \%unique_hash |
838 | if (scalar keys %unique_hash == scalar @unique_cols); |
839 | } |
840 | |
841 | my $row; |
842 | if (@unique_hashes) { |
843 | $row = $self->search(\@unique_hashes, { rows => 1 })->first; |
844 | if ($row) { |
845 | $row->set_columns($hash); |
846 | $row->update; |
847 | } |
848 | } |
849 | |
850 | unless ($row) { |
851 | $row = $self->create($hash); |
852 | } |
853 | |
854 | return $row; |
855 | } |
856 | |
64acc2bc |
857 | =head2 get_cache |
858 | |
859 | Gets the contents of the cache for the resultset. |
860 | |
861 | =cut |
862 | |
863 | sub get_cache { |
864 | my $self = shift; |
865 | return $self->{all_cache} || []; |
866 | } |
867 | |
868 | =head2 set_cache |
869 | |
870 | Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset. |
871 | |
872 | =cut |
873 | |
874 | sub set_cache { |
875 | my ( $self, $data ) = @_; |
876 | $self->throw_exception("set_cache requires an arrayref") |
877 | if ref $data ne 'ARRAY'; |
878 | my $result_class = $self->result_source->result_class; |
879 | foreach( @$data ) { |
880 | $self->throw_exception("cannot cache object of type '$_', expected '$result_class'") |
881 | if ref $_ ne $result_class; |
882 | } |
883 | $self->{all_cache} = $data; |
884 | } |
885 | |
886 | =head2 clear_cache |
887 | |
888 | Clears the cache for the resultset. |
889 | |
890 | =cut |
891 | |
892 | sub clear_cache { |
893 | my $self = shift; |
894 | $self->set_cache([]); |
895 | } |
896 | |
897 | =head2 related_resultset |
898 | |
899 | Returns a related resultset for the supplied relationship name. |
900 | |
901 | $rs = $rs->related_resultset('foo'); |
902 | |
903 | =cut |
904 | |
905 | sub related_resultset { |
906 | my ( $self, $rel, @rest ) = @_; |
907 | $self->{related_resultsets} ||= {}; |
908 | my $resultsets = $self->{related_resultsets}; |
909 | if( !exists $resultsets->{$rel} ) { |
910 | #warn "fetching related resultset for rel '$rel'"; |
911 | my $rel_obj = $self->result_source->relationship_info($rel); |
912 | $self->throw_exception( |
913 | "search_related: result source '" . $self->result_source->name . |
914 | "' has no such relationship ${rel}") |
915 | unless $rel_obj; #die Dumper $self->{attrs}; |
916 | my $rs; |
917 | if( $self->{attrs}->{cache} ) { |
918 | $rs = $self->search(undef); |
919 | } |
920 | else { |
921 | $rs = $self->search(undef, { join => $rel }); |
922 | } |
923 | #use Data::Dumper; die Dumper $rs->{attrs};#$rs = $self->search( undef ); |
924 | #use Data::Dumper; warn Dumper $self->{attrs}, Dumper $rs->{attrs}; |
925 | my $alias = (defined $rs->{attrs}{seen_join}{$rel} |
926 | && $rs->{attrs}{seen_join}{$rel} > 1 |
927 | ? join('_', $rel, $rs->{attrs}{seen_join}{$rel}) |
928 | : $rel); |
929 | $resultsets->{$rel} = |
930 | $self->result_source->schema->resultset($rel_obj->{class} |
931 | )->search( undef, |
932 | { %{$rs->{attrs}}, |
933 | alias => $alias, |
934 | select => undef(), |
935 | as => undef() } |
936 | )->search(@rest); |
937 | } |
938 | return $resultsets->{$rel}; |
939 | } |
940 | |
701da8c4 |
941 | =head2 throw_exception |
942 | |
943 | See Schema's throw_exception |
944 | |
945 | =cut |
946 | |
947 | sub throw_exception { |
948 | my $self=shift; |
949 | $self->result_source->schema->throw_exception(@_); |
950 | } |
951 | |
40dbc108 |
952 | =head1 ATTRIBUTES |
076652e8 |
953 | |
a33df5d4 |
954 | The resultset takes various attributes that modify its behavior. Here's an |
955 | overview of them: |
bfab575a |
956 | |
957 | =head2 order_by |
076652e8 |
958 | |
a33df5d4 |
959 | Which column(s) to order the results by. This is currently passed through |
960 | directly to SQL, so you can give e.g. C<foo DESC> for a descending order. |
076652e8 |
961 | |
87c4e602 |
962 | =head2 cols |
963 | |
964 | =head3 Arguments: (arrayref) |
976f3686 |
965 | |
a33df5d4 |
966 | Shortcut to request a particular set of columns to be retrieved. Adds |
967 | C<me.> onto the start of any column without a C<.> in it and sets C<select> |
968 | from that, then auto-populates C<as> from C<select> as normal. |
976f3686 |
969 | |
87c4e602 |
970 | =head2 include_columns |
971 | |
972 | =head3 Arguments: (arrayref) |
5ac6a044 |
973 | |
974 | Shortcut to include additional columns in the returned results - for example |
975 | |
976 | { include_columns => ['foo.name'], join => ['foo'] } |
977 | |
978 | would add a 'name' column to the information passed to object inflation |
979 | |
87c4e602 |
980 | =head2 select |
981 | |
982 | =head3 Arguments: (arrayref) |
976f3686 |
983 | |
4a28c340 |
984 | Indicates which columns should be selected from the storage. You can use |
985 | column names, or in the case of RDBMS back ends, function or stored procedure |
986 | names: |
987 | |
988 | $rs = $schema->resultset('Foo')->search( |
989 | {}, |
990 | { |
cf7b40ed |
991 | select => [ |
4a28c340 |
992 | 'column_name', |
993 | { count => 'column_to_count' }, |
994 | { sum => 'column_to_sum' } |
cf7b40ed |
995 | ] |
4a28c340 |
996 | } |
997 | ); |
998 | |
999 | When you use function/stored procedure names and do not supply an C<as> |
1000 | attribute, the column names returned are storage-dependent. E.g. MySQL would |
1001 | return a column named C<count(column_to_count)> in the above example. |
976f3686 |
1002 | |
87c4e602 |
1003 | =head2 as |
1004 | |
1005 | =head3 Arguments: (arrayref) |
076652e8 |
1006 | |
4a28c340 |
1007 | Indicates column names for object inflation. This is used in conjunction with |
1008 | C<select>, usually when C<select> contains one or more function or stored |
1009 | procedure names: |
1010 | |
1011 | $rs = $schema->resultset('Foo')->search( |
1012 | {}, |
1013 | { |
cf7b40ed |
1014 | select => [ |
4a28c340 |
1015 | 'column1', |
1016 | { count => 'column2' } |
cf7b40ed |
1017 | ], |
4a28c340 |
1018 | as => [qw/ column1 column2_count /] |
1019 | } |
1020 | ); |
1021 | |
1022 | my $foo = $rs->first(); # get the first Foo |
1023 | |
1024 | If the object against which the search is performed already has an accessor |
1025 | matching a column name specified in C<as>, the value can be retrieved using |
1026 | the accessor as normal: |
1027 | |
1028 | my $column1 = $foo->column1(); |
1029 | |
1030 | If on the other hand an accessor does not exist in the object, you need to |
1031 | use C<get_column> instead: |
1032 | |
1033 | my $column2_count = $foo->get_column('column2_count'); |
1034 | |
1035 | You can create your own accessors if required - see |
1036 | L<DBIx::Class::Manual::Cookbook> for details. |
ee38fa40 |
1037 | |
bfab575a |
1038 | =head2 join |
ee38fa40 |
1039 | |
a33df5d4 |
1040 | Contains a list of relationships that should be joined for this query. For |
1041 | example: |
1042 | |
1043 | # Get CDs by Nine Inch Nails |
1044 | my $rs = $schema->resultset('CD')->search( |
1045 | { 'artist.name' => 'Nine Inch Nails' }, |
1046 | { join => 'artist' } |
1047 | ); |
1048 | |
1049 | Can also contain a hash reference to refer to the other relation's relations. |
1050 | For example: |
1051 | |
1052 | package MyApp::Schema::Track; |
1053 | use base qw/DBIx::Class/; |
1054 | __PACKAGE__->table('track'); |
1055 | __PACKAGE__->add_columns(qw/trackid cd position title/); |
1056 | __PACKAGE__->set_primary_key('trackid'); |
1057 | __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD'); |
1058 | 1; |
1059 | |
1060 | # In your application |
1061 | my $rs = $schema->resultset('Artist')->search( |
1062 | { 'track.title' => 'Teardrop' }, |
1063 | { |
1064 | join => { cd => 'track' }, |
1065 | order_by => 'artist.name', |
1066 | } |
1067 | ); |
1068 | |
2cb360cc |
1069 | If the same join is supplied twice, it will be aliased to <rel>_2 (and |
1070 | similarly for a third time). For e.g. |
1071 | |
1072 | my $rs = $schema->resultset('Artist')->search( |
1073 | { 'cds.title' => 'Foo', |
1074 | 'cds_2.title' => 'Bar' }, |
1075 | { join => [ qw/cds cds/ ] }); |
1076 | |
1077 | will return a set of all artists that have both a cd with title Foo and a cd |
1078 | with title Bar. |
1079 | |
1080 | If you want to fetch related objects from other tables as well, see C<prefetch> |
ae1c90a1 |
1081 | below. |
ee38fa40 |
1082 | |
87c4e602 |
1083 | =head2 prefetch |
1084 | |
1085 | =head3 Arguments: arrayref/hashref |
ee38fa40 |
1086 | |
ae1c90a1 |
1087 | Contains one or more relationships that should be fetched along with the main |
bfab575a |
1088 | query (when they are accessed afterwards they will have already been |
a33df5d4 |
1089 | "prefetched"). This is useful for when you know you will need the related |
ae1c90a1 |
1090 | objects, because it saves at least one query: |
1091 | |
1092 | my $rs = $schema->resultset('Tag')->search( |
1093 | {}, |
1094 | { |
1095 | prefetch => { |
1096 | cd => 'artist' |
1097 | } |
1098 | } |
1099 | ); |
1100 | |
1101 | The initial search results in SQL like the following: |
1102 | |
1103 | SELECT tag.*, cd.*, artist.* FROM tag |
1104 | JOIN cd ON tag.cd = cd.cdid |
1105 | JOIN artist ON cd.artist = artist.artistid |
1106 | |
1107 | L<DBIx::Class> has no need to go back to the database when we access the |
1108 | C<cd> or C<artist> relationships, which saves us two SQL statements in this |
1109 | case. |
1110 | |
2cb360cc |
1111 | Simple prefetches will be joined automatically, so there is no need |
1112 | for a C<join> attribute in the above search. If you're prefetching to |
1113 | depth (e.g. { cd => { artist => 'label' } or similar), you'll need to |
1114 | specify the join as well. |
ae1c90a1 |
1115 | |
1116 | C<prefetch> can be used with the following relationship types: C<belongs_to>, |
2cb360cc |
1117 | C<has_one> (or if you're using C<add_relationship>, any relationship declared |
1118 | with an accessor type of 'single' or 'filter'). |
ee38fa40 |
1119 | |
87c4e602 |
1120 | =head2 from |
1121 | |
1122 | =head3 Arguments: (arrayref) |
ee38fa40 |
1123 | |
4a28c340 |
1124 | The C<from> attribute gives you manual control over the C<FROM> clause of SQL |
1125 | statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN> |
1126 | clauses. |
ee38fa40 |
1127 | |
a33df5d4 |
1128 | NOTE: Use this on your own risk. This allows you to shoot off your foot! |
4a28c340 |
1129 | C<join> will usually do what you need and it is strongly recommended that you |
1130 | avoid using C<from> unless you cannot achieve the desired result using C<join>. |
1131 | |
1132 | In simple terms, C<from> works as follows: |
1133 | |
1134 | [ |
1135 | { <alias> => <table>, -join-type => 'inner|left|right' } |
1136 | [] # nested JOIN (optional) |
1137 | { <table.column> = <foreign_table.foreign_key> } |
1138 | ] |
1139 | |
1140 | JOIN |
1141 | <alias> <table> |
1142 | [JOIN ...] |
1143 | ON <table.column> = <foreign_table.foreign_key> |
1144 | |
1145 | An easy way to follow the examples below is to remember the following: |
1146 | |
1147 | Anything inside "[]" is a JOIN |
1148 | Anything inside "{}" is a condition for the enclosing JOIN |
1149 | |
1150 | The following examples utilize a "person" table in a family tree application. |
1151 | In order to express parent->child relationships, this table is self-joined: |
1152 | |
1153 | # Person->belongs_to('father' => 'Person'); |
1154 | # Person->belongs_to('mother' => 'Person'); |
1155 | |
1156 | C<from> can be used to nest joins. Here we return all children with a father, |
1157 | then search against all mothers of those children: |
1158 | |
1159 | $rs = $schema->resultset('Person')->search( |
1160 | {}, |
1161 | { |
1162 | alias => 'mother', # alias columns in accordance with "from" |
1163 | from => [ |
1164 | { mother => 'person' }, |
1165 | [ |
1166 | [ |
1167 | { child => 'person' }, |
1168 | [ |
1169 | { father => 'person' }, |
1170 | { 'father.person_id' => 'child.father_id' } |
1171 | ] |
1172 | ], |
1173 | { 'mother.person_id' => 'child.mother_id' } |
1174 | ], |
1175 | ] |
1176 | }, |
1177 | ); |
1178 | |
1179 | # Equivalent SQL: |
1180 | # SELECT mother.* FROM person mother |
1181 | # JOIN ( |
1182 | # person child |
1183 | # JOIN person father |
1184 | # ON ( father.person_id = child.father_id ) |
1185 | # ) |
1186 | # ON ( mother.person_id = child.mother_id ) |
1187 | |
1188 | The type of any join can be controlled manually. To search against only people |
1189 | with a father in the person table, we could explicitly use C<INNER JOIN>: |
1190 | |
1191 | $rs = $schema->resultset('Person')->search( |
1192 | {}, |
1193 | { |
1194 | alias => 'child', # alias columns in accordance with "from" |
1195 | from => [ |
1196 | { child => 'person' }, |
1197 | [ |
1198 | { father => 'person', -join-type => 'inner' }, |
1199 | { 'father.id' => 'child.father_id' } |
1200 | ], |
1201 | ] |
1202 | }, |
1203 | ); |
1204 | |
1205 | # Equivalent SQL: |
1206 | # SELECT child.* FROM person child |
1207 | # INNER JOIN person father ON child.father_id = father.id |
ee38fa40 |
1208 | |
bfab575a |
1209 | =head2 page |
076652e8 |
1210 | |
a33df5d4 |
1211 | For a paged resultset, specifies which page to retrieve. Leave unset |
bfab575a |
1212 | for an unpaged resultset. |
076652e8 |
1213 | |
bfab575a |
1214 | =head2 rows |
076652e8 |
1215 | |
4a28c340 |
1216 | For a paged resultset, how many rows per page: |
1217 | |
1218 | rows => 10 |
1219 | |
1220 | Can also be used to simulate an SQL C<LIMIT>. |
076652e8 |
1221 | |
87c4e602 |
1222 | =head2 group_by |
1223 | |
1224 | =head3 Arguments: (arrayref) |
54540863 |
1225 | |
bda4c2b8 |
1226 | A arrayref of columns to group by. Can include columns of joined tables. |
54540863 |
1227 | |
675ce4a6 |
1228 | group_by => [qw/ column1 column2 ... /] |
1229 | |
54540863 |
1230 | =head2 distinct |
1231 | |
a33df5d4 |
1232 | Set to 1 to group by all columns. |
1233 | |
1234 | For more examples of using these attributes, see |
1235 | L<DBIx::Class::Manual::Cookbook>. |
54540863 |
1236 | |
bfab575a |
1237 | =cut |
076652e8 |
1238 | |
89c0a5a2 |
1239 | 1; |