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