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/); |
a50bcd52 |
14 | __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/); |
701da8c4 |
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 $class; |
5e8b1b2a |
72 | |
fea3d045 |
73 | my ($source, $attrs) = @_; |
b98e75f6 |
74 | #use Data::Dumper; warn Dumper($attrs); |
ea20d0fd |
75 | $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } }; |
6aeb9185 |
76 | my $alias = ($attrs->{alias} ||= 'me'); |
5e8b1b2a |
77 | |
78 | $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols}; |
1c258fc1 |
79 | delete $attrs->{as} if $attrs->{columns}; |
5e8b1b2a |
80 | $attrs->{columns} ||= [ $source->columns ] unless $attrs->{select}; |
1c258fc1 |
81 | $attrs->{select} = [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ] |
82 | if $attrs->{columns}; |
5e8b1b2a |
83 | $attrs->{as} ||= [ map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]; |
5ac6a044 |
84 | if (my $include = delete $attrs->{include_columns}) { |
85 | push(@{$attrs->{select}}, @$include); |
86 | push(@{$attrs->{as}}, map { m/([^\.]+)$/; $1; } @$include); |
87 | } |
976f3686 |
88 | #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/}); |
5e8b1b2a |
89 | |
fea3d045 |
90 | $attrs->{from} ||= [ { $alias => $source->from } ]; |
8fab5eef |
91 | $attrs->{seen_join} ||= {}; |
5e8b1b2a |
92 | my %seen; |
b52e9bf8 |
93 | if (my $join = delete $attrs->{join}) { |
5e8b1b2a |
94 | foreach my $j (ref $join eq 'ARRAY' ? @$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 | } |
5e8b1b2a |
103 | |
54540863 |
104 | $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct}; |
1c258fc1 |
105 | $attrs->{order_by} = [ $attrs->{order_by} ] if $attrs->{order_by} and !ref($attrs->{order_by}); |
a86b1efe |
106 | $attrs->{order_by} ||= []; |
107 | |
555af3d9 |
108 | my $collapse = $attrs->{collapse} || {}; |
b3e8ac9b |
109 | if (my $prefetch = delete $attrs->{prefetch}) { |
0f66a01b |
110 | my @pre_order; |
5e8b1b2a |
111 | foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) { |
112 | if ( ref $p eq 'HASH' ) { |
b3e8ac9b |
113 | foreach my $key (keys %$p) { |
114 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
115 | unless $seen{$key}; |
116 | } |
5e8b1b2a |
117 | } else { |
b3e8ac9b |
118 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
119 | unless $seen{$p}; |
120 | } |
a86b1efe |
121 | my @prefetch = $source->resolve_prefetch( |
0f66a01b |
122 | $p, $attrs->{alias}, {}, \@pre_order, $collapse); |
489709af |
123 | push(@{$attrs->{select}}, map { $_->[0] } @prefetch); |
124 | push(@{$attrs->{as}}, map { $_->[1] } @prefetch); |
b3e8ac9b |
125 | } |
0f66a01b |
126 | push(@{$attrs->{order_by}}, @pre_order); |
fef5d100 |
127 | } |
555af3d9 |
128 | $attrs->{collapse} = $collapse; |
5e8b1b2a |
129 | # use Data::Dumper; warn Dumper($collapse) if keys %{$collapse}; |
555af3d9 |
130 | |
6aeb9185 |
131 | if ($attrs->{page}) { |
132 | $attrs->{rows} ||= 10; |
133 | $attrs->{offset} ||= 0; |
134 | $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1)); |
135 | } |
0f66a01b |
136 | |
5e8b1b2a |
137 | bless { |
701da8c4 |
138 | result_source => $source, |
a50bcd52 |
139 | result_class => $attrs->{result_class} || $source->result_class, |
89c0a5a2 |
140 | cond => $attrs->{where}, |
0a3c5b43 |
141 | from => $attrs->{from}, |
0f66a01b |
142 | collapse => $collapse, |
3c5b25c5 |
143 | count => undef, |
93b004d3 |
144 | page => delete $attrs->{page}, |
3c5b25c5 |
145 | pager => undef, |
5e8b1b2a |
146 | attrs => $attrs |
147 | }, $class; |
89c0a5a2 |
148 | } |
149 | |
bfab575a |
150 | =head2 search |
0a3c5b43 |
151 | |
87f0da6a |
152 | my @obj = $rs->search({ foo => 3 }); # "... WHERE foo = 3" |
153 | my $new_rs = $rs->search({ foo => 3 }); |
154 | |
6009260a |
155 | If you need to pass in additional attributes but no additional condition, |
5e8b1b2a |
156 | call it as C<search(undef, \%attrs);>. |
87f0da6a |
157 | |
a33df5d4 |
158 | # "SELECT foo, bar FROM $class_table" |
5e8b1b2a |
159 | my @all = $class->search(undef, { columns => [qw/foo bar/] }); |
0a3c5b43 |
160 | |
161 | =cut |
162 | |
163 | sub search { |
164 | my $self = shift; |
165 | |
ff7bb7a1 |
166 | my $rs; |
167 | if( @_ ) { |
168 | |
169 | my $attrs = { %{$self->{attrs}} }; |
8839560b |
170 | my $having = delete $attrs->{having}; |
ff7bb7a1 |
171 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
172 | $attrs = { %$attrs, %{ pop(@_) } }; |
173 | } |
6009260a |
174 | |
3e0e9e27 |
175 | my $where = (@_ |
176 | ? ((@_ == 1 || ref $_[0] eq "HASH") |
177 | ? shift |
178 | : ((@_ % 2) |
179 | ? $self->throw_exception( |
180 | "Odd number of arguments to search") |
181 | : {@_})) |
182 | : undef()); |
ff7bb7a1 |
183 | if (defined $where) { |
184 | $where = (defined $attrs->{where} |
ad3d2d7c |
185 | ? { '-and' => |
186 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
187 | $where, $attrs->{where} ] } |
0a3c5b43 |
188 | : $where); |
ff7bb7a1 |
189 | $attrs->{where} = $where; |
190 | } |
0a3c5b43 |
191 | |
8839560b |
192 | if (defined $having) { |
193 | $having = (defined $attrs->{having} |
194 | ? { '-and' => |
195 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
196 | $having, $attrs->{having} ] } |
197 | : $having); |
198 | $attrs->{having} = $having; |
199 | } |
200 | |
ff7bb7a1 |
201 | $rs = (ref $self)->new($self->result_source, $attrs); |
202 | } |
203 | else { |
204 | $rs = $self; |
205 | $rs->reset(); |
206 | } |
0a3c5b43 |
207 | return (wantarray ? $rs->all : $rs); |
208 | } |
209 | |
87f0da6a |
210 | =head2 search_literal |
211 | |
6009260a |
212 | my @obj = $rs->search_literal($literal_where_cond, @bind); |
213 | my $new_rs = $rs->search_literal($literal_where_cond, @bind); |
214 | |
215 | Pass a literal chunk of SQL to be added to the conditional part of the |
87f0da6a |
216 | resultset. |
6009260a |
217 | |
bfab575a |
218 | =cut |
fd9f5466 |
219 | |
6009260a |
220 | sub search_literal { |
221 | my ($self, $cond, @vals) = @_; |
222 | my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {}); |
223 | $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ]; |
224 | return $self->search(\$cond, $attrs); |
225 | } |
0a3c5b43 |
226 | |
87c4e602 |
227 | =head2 find |
228 | |
229 | =head3 Arguments: (@colvalues) | (\%cols, \%attrs?) |
87f0da6a |
230 | |
231 | Finds a row based on its primary key or unique constraint. For example: |
232 | |
87f0da6a |
233 | my $cd = $schema->resultset('CD')->find(5); |
234 | |
235 | Also takes an optional C<key> attribute, to search by a specific key or unique |
236 | constraint. For example: |
237 | |
fd9f5466 |
238 | my $cd = $schema->resultset('CD')->find( |
87f0da6a |
239 | { |
240 | artist => 'Massive Attack', |
241 | title => 'Mezzanine', |
242 | }, |
243 | { key => 'artist_title' } |
244 | ); |
245 | |
a33df5d4 |
246 | See also L</find_or_create> and L</update_or_create>. |
247 | |
87f0da6a |
248 | =cut |
716b3d29 |
249 | |
250 | sub find { |
251 | my ($self, @vals) = @_; |
252 | my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {}); |
87f0da6a |
253 | |
701da8c4 |
254 | my @cols = $self->result_source->primary_columns; |
87f0da6a |
255 | if (exists $attrs->{key}) { |
701da8c4 |
256 | my %uniq = $self->result_source->unique_constraints; |
87f0da6a |
257 | $self->( "Unknown key " . $attrs->{key} . " on " . $self->name ) |
258 | unless exists $uniq{$attrs->{key}}; |
259 | @cols = @{ $uniq{$attrs->{key}} }; |
260 | } |
261 | #use Data::Dumper; warn Dumper($attrs, @vals, @cols); |
701da8c4 |
262 | $self->throw_exception( "Can't find unless a primary key or unique constraint is defined" ) |
87f0da6a |
263 | unless @cols; |
264 | |
716b3d29 |
265 | my $query; |
266 | if (ref $vals[0] eq 'HASH') { |
01bc091e |
267 | $query = { %{$vals[0]} }; |
87f0da6a |
268 | } elsif (@cols == @vals) { |
716b3d29 |
269 | $query = {}; |
87f0da6a |
270 | @{$query}{@cols} = @vals; |
716b3d29 |
271 | } else { |
272 | $query = {@vals}; |
273 | } |
01bc091e |
274 | foreach (keys %$query) { |
275 | next if m/\./; |
276 | $query->{$self->{attrs}{alias}.'.'.$_} = delete $query->{$_}; |
277 | } |
716b3d29 |
278 | #warn Dumper($query); |
8389d433 |
279 | |
280 | if (keys %$attrs) { |
281 | my $rs = $self->search($query,$attrs); |
282 | return keys %{$rs->{collapse}} ? $rs->next : $rs->single; |
283 | } else { |
284 | return keys %{$self->{collapse}} ? $self->search($query)->next : $self->single($query); |
285 | } |
716b3d29 |
286 | } |
287 | |
b52e9bf8 |
288 | =head2 search_related |
289 | |
290 | $rs->search_related('relname', $cond?, $attrs?); |
291 | |
a33df5d4 |
292 | Search the specified relationship. Optionally specify a condition for matching |
293 | records. |
294 | |
b52e9bf8 |
295 | =cut |
296 | |
6aeb9185 |
297 | sub search_related { |
64acc2bc |
298 | return shift->related_resultset(shift)->search(@_); |
6aeb9185 |
299 | } |
b52e9bf8 |
300 | |
bfab575a |
301 | =head2 cursor |
ee38fa40 |
302 | |
bfab575a |
303 | Returns a storage-driven cursor to the given resultset. |
ee38fa40 |
304 | |
305 | =cut |
306 | |
73f58123 |
307 | sub cursor { |
308 | my ($self) = @_; |
701da8c4 |
309 | my ($attrs) = $self->{attrs}; |
6aeb9185 |
310 | $attrs = { %$attrs }; |
73f58123 |
311 | return $self->{cursor} |
701da8c4 |
312 | ||= $self->result_source->storage->select($self->{from}, $attrs->{select}, |
73f58123 |
313 | $attrs->{where},$attrs); |
314 | } |
315 | |
a04ab285 |
316 | =head2 single |
317 | |
318 | Inflates the first result without creating a cursor |
319 | |
320 | =cut |
321 | |
322 | sub single { |
323 | my ($self, $extra) = @_; |
324 | my ($attrs) = $self->{attrs}; |
325 | $attrs = { %$attrs }; |
326 | if ($extra) { |
327 | if (defined $attrs->{where}) { |
328 | $attrs->{where} = { |
329 | '-and' |
330 | => [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
331 | delete $attrs->{where}, $extra ] |
332 | }; |
333 | } else { |
334 | $attrs->{where} = $extra; |
335 | } |
336 | } |
337 | my @data = $self->result_source->storage->select_single( |
338 | $self->{from}, $attrs->{select}, |
339 | $attrs->{where},$attrs); |
340 | return (@data ? $self->_construct_object(@data) : ()); |
341 | } |
342 | |
343 | |
87f0da6a |
344 | =head2 search_like |
345 | |
a33df5d4 |
346 | Perform a search, but use C<LIKE> instead of equality as the condition. Note |
347 | that this is simply a convenience method; you most likely want to use |
348 | L</search> with specific operators. |
349 | |
350 | For more information, see L<DBIx::Class::Manual::Cookbook>. |
87f0da6a |
351 | |
352 | =cut |
58a4bd18 |
353 | |
354 | sub search_like { |
355 | my $class = shift; |
356 | my $attrs = { }; |
357 | if (@_ > 1 && ref $_[$#_] eq 'HASH') { |
358 | $attrs = pop(@_); |
359 | } |
360 | my $query = ref $_[0] eq "HASH" ? { %{shift()} }: {@_}; |
361 | $query->{$_} = { 'like' => $query->{$_} } for keys %$query; |
362 | return $class->search($query, { %$attrs }); |
363 | } |
364 | |
87c4e602 |
365 | =head2 slice |
366 | |
367 | =head3 Arguments: ($first, $last) |
ee38fa40 |
368 | |
bfab575a |
369 | Returns a subset of elements from the resultset. |
ee38fa40 |
370 | |
371 | =cut |
372 | |
89c0a5a2 |
373 | sub slice { |
374 | my ($self, $min, $max) = @_; |
375 | my $attrs = { %{ $self->{attrs} || {} } }; |
6aeb9185 |
376 | $attrs->{offset} ||= 0; |
377 | $attrs->{offset} += $min; |
89c0a5a2 |
378 | $attrs->{rows} = ($max ? ($max - $min + 1) : 1); |
701da8c4 |
379 | my $slice = (ref $self)->new($self->result_source, $attrs); |
89c0a5a2 |
380 | return (wantarray ? $slice->all : $slice); |
381 | } |
382 | |
87f0da6a |
383 | =head2 next |
ee38fa40 |
384 | |
a33df5d4 |
385 | Returns the next element in the resultset (C<undef> is there is none). |
386 | |
387 | Can be used to efficiently iterate over records in the resultset: |
388 | |
5e8b1b2a |
389 | my $rs = $schema->resultset('CD')->search; |
a33df5d4 |
390 | while (my $cd = $rs->next) { |
391 | print $cd->title; |
392 | } |
ee38fa40 |
393 | |
394 | =cut |
395 | |
89c0a5a2 |
396 | sub next { |
397 | my ($self) = @_; |
3e0e9e27 |
398 | my $cache; |
399 | if( @{$cache = $self->{all_cache} || []}) { |
64acc2bc |
400 | $self->{all_cache_position} ||= 0; |
401 | my $obj = $cache->[$self->{all_cache_position}]; |
402 | $self->{all_cache_position}++; |
403 | return $obj; |
404 | } |
3e0e9e27 |
405 | if ($self->{attrs}{cache}) { |
0f66a01b |
406 | $self->{all_cache_position} = 1; |
3e0e9e27 |
407 | return ($self->all)[0]; |
408 | } |
0f66a01b |
409 | my @row = (exists $self->{stashed_row} |
410 | ? @{delete $self->{stashed_row}} |
411 | : $self->cursor->next); |
a953d8d9 |
412 | # warn Dumper(\@row); use Data::Dumper; |
89c0a5a2 |
413 | return unless (@row); |
c7ce65e6 |
414 | return $self->_construct_object(@row); |
415 | } |
416 | |
417 | sub _construct_object { |
418 | my ($self, @row) = @_; |
b3e8ac9b |
419 | my @as = @{ $self->{attrs}{as} }; |
0f66a01b |
420 | |
421 | my $info = $self->_collapse_result(\@as, \@row); |
422 | |
a50bcd52 |
423 | my $new = $self->result_class->inflate_result($self->result_source, @$info); |
0f66a01b |
424 | |
33ce49d6 |
425 | $new = $self->{attrs}{record_filter}->($new) |
426 | if exists $self->{attrs}{record_filter}; |
f9cc31dd |
427 | |
33ce49d6 |
428 | return $new; |
89c0a5a2 |
429 | } |
430 | |
0f66a01b |
431 | sub _collapse_result { |
432 | my ($self, $as, $row, $prefix) = @_; |
433 | |
434 | my %const; |
435 | |
436 | my @copy = @$row; |
5a5bec6c |
437 | foreach my $this_as (@$as) { |
438 | my $val = shift @copy; |
439 | if (defined $prefix) { |
440 | if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) { |
441 | my $remain = $1; |
442 | $remain =~ /^(?:(.*)\.)?([^\.]+)$/; |
443 | $const{$1||''}{$2} = $val; |
444 | } |
445 | } else { |
446 | $this_as =~ /^(?:(.*)\.)?([^\.]+)$/; |
447 | $const{$1||''}{$2} = $val; |
0f66a01b |
448 | } |
0f66a01b |
449 | } |
450 | |
0f66a01b |
451 | my $info = [ {}, {} ]; |
452 | foreach my $key (keys %const) { |
453 | if (length $key) { |
454 | my $target = $info; |
455 | my @parts = split(/\./, $key); |
456 | foreach my $p (@parts) { |
457 | $target = $target->[1]->{$p} ||= []; |
458 | } |
459 | $target->[0] = $const{$key}; |
460 | } else { |
461 | $info->[0] = $const{$key}; |
462 | } |
463 | } |
464 | |
5a5bec6c |
465 | my @collapse = (defined($prefix) |
466 | ? (map { (m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()); } |
467 | keys %{$self->{collapse}}) |
468 | : keys %{$self->{collapse}}); |
469 | if (@collapse) { |
470 | my ($c) = sort { length $a <=> length $b } @collapse; |
0f66a01b |
471 | my $target = $info; |
0f66a01b |
472 | foreach my $p (split(/\./, $c)) { |
5a5bec6c |
473 | $target = $target->[1]->{$p} ||= []; |
0f66a01b |
474 | } |
5a5bec6c |
475 | my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c); |
476 | my @co_key = @{$self->{collapse}{$c_prefix}}; |
0f66a01b |
477 | my %co_check = map { ($_, $target->[0]->{$_}); } @co_key; |
5a5bec6c |
478 | my $tree = $self->_collapse_result($as, $row, $c_prefix); |
0f66a01b |
479 | my (@final, @raw); |
5a5bec6c |
480 | while ( !(grep { |
481 | !defined($tree->[0]->{$_}) |
482 | || $co_check{$_} ne $tree->[0]->{$_} |
483 | } @co_key) ) { |
0f66a01b |
484 | push(@final, $tree); |
485 | last unless (@raw = $self->cursor->next); |
486 | $row = $self->{stashed_row} = \@raw; |
5a5bec6c |
487 | $tree = $self->_collapse_result($as, $row, $c_prefix); |
488 | #warn Data::Dumper::Dumper($tree, $row); |
0f66a01b |
489 | } |
490 | @{$target} = @final; |
0f66a01b |
491 | } |
492 | |
0f66a01b |
493 | return $info; |
494 | } |
495 | |
87c4e602 |
496 | =head2 result_source |
701da8c4 |
497 | |
498 | Returns a reference to the result source for this recordset. |
499 | |
500 | =cut |
501 | |
502 | |
bfab575a |
503 | =head2 count |
ee38fa40 |
504 | |
bfab575a |
505 | Performs an SQL C<COUNT> with the same query as the resultset was built |
6009260a |
506 | with to find the number of elements. If passed arguments, does a search |
507 | on the resultset and counts the results of that. |
ee38fa40 |
508 | |
bda4c2b8 |
509 | Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY> |
510 | using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do |
511 | not support C<DISTINCT> with multiple columns. If you are using such a |
512 | database, you should only use columns from the main table in your C<group_by> |
513 | clause. |
514 | |
ee38fa40 |
515 | =cut |
516 | |
89c0a5a2 |
517 | sub count { |
6009260a |
518 | my $self = shift; |
519 | return $self->search(@_)->count if @_ && defined $_[0]; |
6aeb9185 |
520 | unless (defined $self->{count}) { |
64acc2bc |
521 | return scalar @{ $self->get_cache } |
522 | if @{ $self->get_cache }; |
15c382be |
523 | my $group_by; |
524 | my $select = { 'count' => '*' }; |
8839560b |
525 | my $attrs = { %{ $self->{attrs} } }; |
526 | if( $group_by = delete $attrs->{group_by} ) { |
527 | delete $attrs->{having}; |
dec2517f |
528 | my @distinct = (ref $group_by ? @$group_by : ($group_by)); |
15c382be |
529 | # todo: try CONCAT for multi-column pk |
530 | my @pk = $self->result_source->primary_columns; |
531 | if( scalar(@pk) == 1 ) { |
532 | my $pk = shift(@pk); |
8839560b |
533 | my $alias = $attrs->{alias}; |
15c382be |
534 | my $re = qr/^($alias\.)?$pk$/; |
d0f1e63f |
535 | foreach my $column ( @distinct) { |
15c382be |
536 | if( $column =~ $re ) { |
537 | @distinct = ( $column ); |
538 | last; |
539 | } |
540 | } |
541 | } |
542 | |
543 | $select = { count => { 'distinct' => \@distinct } }; |
544 | #use Data::Dumper; die Dumper $select; |
545 | } |
546 | |
8839560b |
547 | $attrs->{select} = $select; |
548 | $attrs->{as} = [ 'count' ]; |
ea20d0fd |
549 | # offset, order by and page are not needed to count. record_filter is cdbi |
550 | delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/; |
3c5b25c5 |
551 | |
701da8c4 |
552 | ($self->{count}) = (ref $self)->new($self->result_source, $attrs)->cursor->next; |
3c5b25c5 |
553 | } |
554 | return 0 unless $self->{count}; |
6aeb9185 |
555 | my $count = $self->{count}; |
556 | $count -= $self->{attrs}{offset} if $self->{attrs}{offset}; |
557 | $count = $self->{attrs}{rows} if |
558 | ($self->{attrs}{rows} && $self->{attrs}{rows} < $count); |
559 | return $count; |
89c0a5a2 |
560 | } |
561 | |
bfab575a |
562 | =head2 count_literal |
6009260a |
563 | |
a33df5d4 |
564 | Calls L</search_literal> with the passed arguments, then L</count>. |
6009260a |
565 | |
566 | =cut |
567 | |
568 | sub count_literal { shift->search_literal(@_)->count; } |
569 | |
bfab575a |
570 | =head2 all |
ee38fa40 |
571 | |
bfab575a |
572 | Returns all elements in the resultset. Called implictly if the resultset |
573 | is returned in list context. |
ee38fa40 |
574 | |
575 | =cut |
576 | |
89c0a5a2 |
577 | sub all { |
578 | my ($self) = @_; |
64acc2bc |
579 | return @{ $self->get_cache } |
580 | if @{ $self->get_cache }; |
5a5bec6c |
581 | |
582 | my @obj; |
583 | |
584 | if (keys %{$self->{collapse}}) { |
585 | # Using $self->cursor->all is really just an optimisation. |
586 | # If we're collapsing has_many prefetches it probably makes |
587 | # very little difference, and this is cleaner than hacking |
588 | # _construct_object to survive the approach |
589 | my @row; |
590 | $self->cursor->reset; |
591 | while (@row = $self->cursor->next) { |
592 | push(@obj, $self->_construct_object(@row)); |
593 | } |
594 | } else { |
595 | @obj = map { $self->_construct_object(@$_); } |
596 | $self->cursor->all; |
597 | } |
598 | |
64acc2bc |
599 | if( $self->{attrs}->{cache} ) { |
64acc2bc |
600 | $self->set_cache( \@obj ); |
64acc2bc |
601 | } |
5a5bec6c |
602 | |
603 | return @obj; |
89c0a5a2 |
604 | } |
605 | |
bfab575a |
606 | =head2 reset |
ee38fa40 |
607 | |
bfab575a |
608 | Resets the resultset's cursor, so you can iterate through the elements again. |
ee38fa40 |
609 | |
610 | =cut |
611 | |
89c0a5a2 |
612 | sub reset { |
613 | my ($self) = @_; |
64acc2bc |
614 | $self->{all_cache_position} = 0; |
73f58123 |
615 | $self->cursor->reset; |
89c0a5a2 |
616 | return $self; |
617 | } |
618 | |
bfab575a |
619 | =head2 first |
ee38fa40 |
620 | |
bfab575a |
621 | Resets the resultset and returns the first element. |
ee38fa40 |
622 | |
623 | =cut |
624 | |
89c0a5a2 |
625 | sub first { |
626 | return $_[0]->reset->next; |
627 | } |
628 | |
87c4e602 |
629 | =head2 update |
630 | |
631 | =head3 Arguments: (\%values) |
c01ab172 |
632 | |
a33df5d4 |
633 | Sets the specified columns in the resultset to the supplied values. |
c01ab172 |
634 | |
635 | =cut |
636 | |
637 | sub update { |
638 | my ($self, $values) = @_; |
701da8c4 |
639 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
640 | return $self->result_source->storage->update( |
641 | $self->result_source->from, $values, $self->{cond}); |
c01ab172 |
642 | } |
643 | |
87c4e602 |
644 | =head2 update_all |
645 | |
646 | =head3 Arguments: (\%values) |
c01ab172 |
647 | |
a33df5d4 |
648 | Fetches all objects and updates them one at a time. Note that C<update_all> |
649 | will run cascade triggers while L</update> will not. |
c01ab172 |
650 | |
651 | =cut |
652 | |
653 | sub update_all { |
654 | my ($self, $values) = @_; |
701da8c4 |
655 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
c01ab172 |
656 | foreach my $obj ($self->all) { |
657 | $obj->set_columns($values)->update; |
658 | } |
659 | return 1; |
660 | } |
661 | |
bfab575a |
662 | =head2 delete |
ee38fa40 |
663 | |
c01ab172 |
664 | Deletes the contents of the resultset from its result source. |
ee38fa40 |
665 | |
666 | =cut |
667 | |
28927b50 |
668 | sub delete { |
89c0a5a2 |
669 | my ($self) = @_; |
ca4b5ab7 |
670 | my $del = {}; |
671 | $self->throw_exception("Can't delete on resultset with condition unless hash or array") |
672 | unless (ref($self->{cond}) eq 'HASH' || ref($self->{cond}) eq 'ARRAY'); |
673 | if (ref $self->{cond} eq 'ARRAY') { |
674 | $del = [ map { my %hash; |
675 | foreach my $key (keys %{$_}) { |
676 | $key =~ /([^\.]+)$/; |
677 | $hash{$1} = $_->{$key}; |
678 | }; \%hash; } @{$self->{cond}} ]; |
679 | } elsif ((keys %{$self->{cond}})[0] eq '-and') { |
680 | $del->{-and} = [ map { my %hash; |
681 | foreach my $key (keys %{$_}) { |
682 | $key =~ /([^\.]+)$/; |
683 | $hash{$1} = $_->{$key}; |
684 | }; \%hash; } @{$self->{cond}{-and}} ]; |
685 | } else { |
686 | foreach my $key (keys %{$self->{cond}}) { |
687 | $key =~ /([^\.]+)$/; |
688 | $del->{$1} = $self->{cond}{$key}; |
689 | } |
690 | } |
691 | $self->result_source->storage->delete($self->result_source->from, $del); |
89c0a5a2 |
692 | return 1; |
693 | } |
694 | |
c01ab172 |
695 | =head2 delete_all |
696 | |
a33df5d4 |
697 | Fetches all objects and deletes them one at a time. Note that C<delete_all> |
698 | will run cascade triggers while L</delete> will not. |
c01ab172 |
699 | |
700 | =cut |
701 | |
702 | sub delete_all { |
703 | my ($self) = @_; |
704 | $_->delete for $self->all; |
705 | return 1; |
706 | } |
28927b50 |
707 | |
bfab575a |
708 | =head2 pager |
ee38fa40 |
709 | |
710 | Returns a L<Data::Page> object for the current resultset. Only makes |
a33df5d4 |
711 | sense for queries with a C<page> attribute. |
ee38fa40 |
712 | |
713 | =cut |
714 | |
3c5b25c5 |
715 | sub pager { |
716 | my ($self) = @_; |
717 | my $attrs = $self->{attrs}; |
701da8c4 |
718 | $self->throw_exception("Can't create pager for non-paged rs") unless $self->{page}; |
6aeb9185 |
719 | $attrs->{rows} ||= 10; |
720 | $self->count; |
721 | return $self->{pager} ||= Data::Page->new( |
93b004d3 |
722 | $self->{count}, $attrs->{rows}, $self->{page}); |
3c5b25c5 |
723 | } |
724 | |
87c4e602 |
725 | =head2 page |
726 | |
727 | =head3 Arguments: ($page_num) |
ee38fa40 |
728 | |
bfab575a |
729 | Returns a new resultset for the specified page. |
ee38fa40 |
730 | |
731 | =cut |
732 | |
3c5b25c5 |
733 | sub page { |
734 | my ($self, $page) = @_; |
6aeb9185 |
735 | my $attrs = { %{$self->{attrs}} }; |
3c5b25c5 |
736 | $attrs->{page} = $page; |
701da8c4 |
737 | return (ref $self)->new($self->result_source, $attrs); |
fea3d045 |
738 | } |
739 | |
87c4e602 |
740 | =head2 new_result |
741 | |
742 | =head3 Arguments: (\%vals) |
fea3d045 |
743 | |
87f0da6a |
744 | Creates a result in the resultset's result class. |
fea3d045 |
745 | |
746 | =cut |
747 | |
748 | sub new_result { |
749 | my ($self, $values) = @_; |
701da8c4 |
750 | $self->throw_exception( "new_result needs a hash" ) |
fea3d045 |
751 | unless (ref $values eq 'HASH'); |
701da8c4 |
752 | $self->throw_exception( "Can't abstract implicit construct, condition not a hash" ) |
fea3d045 |
753 | if ($self->{cond} && !(ref $self->{cond} eq 'HASH')); |
754 | my %new = %$values; |
755 | my $alias = $self->{attrs}{alias}; |
756 | foreach my $key (keys %{$self->{cond}||{}}) { |
757 | $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:$alias\.)?([^\.]+)$/); |
758 | } |
a50bcd52 |
759 | my $obj = $self->result_class->new(\%new); |
701da8c4 |
760 | $obj->result_source($self->result_source) if $obj->can('result_source'); |
097d3227 |
761 | $obj; |
fea3d045 |
762 | } |
763 | |
87c4e602 |
764 | =head2 create |
765 | |
766 | =head3 Arguments: (\%vals) |
fea3d045 |
767 | |
87f0da6a |
768 | Inserts a record into the resultset and returns the object. |
fea3d045 |
769 | |
a33df5d4 |
770 | Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. |
fea3d045 |
771 | |
772 | =cut |
773 | |
774 | sub create { |
775 | my ($self, $attrs) = @_; |
701da8c4 |
776 | $self->throw_exception( "create needs a hashref" ) unless ref $attrs eq 'HASH'; |
fea3d045 |
777 | return $self->new_result($attrs)->insert; |
3c5b25c5 |
778 | } |
779 | |
87c4e602 |
780 | =head2 find_or_create |
781 | |
782 | =head3 Arguments: (\%vals, \%attrs?) |
87f0da6a |
783 | |
784 | $class->find_or_create({ key => $val, ... }); |
c2b15ecc |
785 | |
fd9f5466 |
786 | Searches for a record matching the search condition; if it doesn't find one, |
787 | creates one and returns that instead. |
87f0da6a |
788 | |
87f0da6a |
789 | my $cd = $schema->resultset('CD')->find_or_create({ |
790 | cdid => 5, |
791 | artist => 'Massive Attack', |
792 | title => 'Mezzanine', |
793 | year => 2005, |
794 | }); |
795 | |
796 | Also takes an optional C<key> attribute, to search by a specific key or unique |
797 | constraint. For example: |
798 | |
799 | my $cd = $schema->resultset('CD')->find_or_create( |
800 | { |
801 | artist => 'Massive Attack', |
802 | title => 'Mezzanine', |
803 | }, |
804 | { key => 'artist_title' } |
805 | ); |
806 | |
807 | See also L</find> and L</update_or_create>. |
808 | |
c2b15ecc |
809 | =cut |
810 | |
811 | sub find_or_create { |
812 | my $self = shift; |
87f0da6a |
813 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
814 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
815 | my $exists = $self->find($hash, $attrs); |
c2b15ecc |
816 | return defined($exists) ? $exists : $self->create($hash); |
817 | } |
818 | |
87f0da6a |
819 | =head2 update_or_create |
820 | |
821 | $class->update_or_create({ key => $val, ... }); |
822 | |
823 | First, search for an existing row matching one of the unique constraints |
824 | (including the primary key) on the source of this resultset. If a row is |
825 | found, update it with the other given column values. Otherwise, create a new |
826 | row. |
827 | |
828 | Takes an optional C<key> attribute to search on a specific unique constraint. |
829 | For example: |
830 | |
831 | # In your application |
832 | my $cd = $schema->resultset('CD')->update_or_create( |
833 | { |
834 | artist => 'Massive Attack', |
835 | title => 'Mezzanine', |
836 | year => 1998, |
837 | }, |
838 | { key => 'artist_title' } |
839 | ); |
840 | |
841 | If no C<key> is specified, it searches on all unique constraints defined on the |
842 | source, including the primary key. |
843 | |
844 | If the C<key> is specified as C<primary>, search only on the primary key. |
845 | |
a33df5d4 |
846 | See also L</find> and L</find_or_create>. |
847 | |
87f0da6a |
848 | =cut |
849 | |
850 | sub update_or_create { |
851 | my $self = shift; |
852 | |
853 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
854 | my $hash = ref $_[0] eq "HASH" ? shift : {@_}; |
855 | |
701da8c4 |
856 | my %unique_constraints = $self->result_source->unique_constraints; |
87f0da6a |
857 | my @constraint_names = (exists $attrs->{key} |
858 | ? ($attrs->{key}) |
859 | : keys %unique_constraints); |
860 | |
861 | my @unique_hashes; |
862 | foreach my $name (@constraint_names) { |
863 | my @unique_cols = @{ $unique_constraints{$name} }; |
864 | my %unique_hash = |
865 | map { $_ => $hash->{$_} } |
866 | grep { exists $hash->{$_} } |
867 | @unique_cols; |
868 | |
869 | push @unique_hashes, \%unique_hash |
870 | if (scalar keys %unique_hash == scalar @unique_cols); |
871 | } |
872 | |
873 | my $row; |
874 | if (@unique_hashes) { |
875 | $row = $self->search(\@unique_hashes, { rows => 1 })->first; |
876 | if ($row) { |
877 | $row->set_columns($hash); |
878 | $row->update; |
879 | } |
880 | } |
881 | |
882 | unless ($row) { |
883 | $row = $self->create($hash); |
884 | } |
885 | |
886 | return $row; |
887 | } |
888 | |
64acc2bc |
889 | =head2 get_cache |
890 | |
891 | Gets the contents of the cache for the resultset. |
892 | |
893 | =cut |
894 | |
895 | sub get_cache { |
896 | my $self = shift; |
897 | return $self->{all_cache} || []; |
898 | } |
899 | |
900 | =head2 set_cache |
901 | |
902 | Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset. |
903 | |
904 | =cut |
905 | |
906 | sub set_cache { |
907 | my ( $self, $data ) = @_; |
908 | $self->throw_exception("set_cache requires an arrayref") |
909 | if ref $data ne 'ARRAY'; |
a50bcd52 |
910 | my $result_class = $self->result_class; |
64acc2bc |
911 | foreach( @$data ) { |
912 | $self->throw_exception("cannot cache object of type '$_', expected '$result_class'") |
913 | if ref $_ ne $result_class; |
914 | } |
915 | $self->{all_cache} = $data; |
916 | } |
917 | |
918 | =head2 clear_cache |
919 | |
920 | Clears the cache for the resultset. |
921 | |
922 | =cut |
923 | |
924 | sub clear_cache { |
925 | my $self = shift; |
926 | $self->set_cache([]); |
927 | } |
928 | |
929 | =head2 related_resultset |
930 | |
931 | Returns a related resultset for the supplied relationship name. |
932 | |
933 | $rs = $rs->related_resultset('foo'); |
934 | |
935 | =cut |
936 | |
937 | sub related_resultset { |
938 | my ( $self, $rel, @rest ) = @_; |
939 | $self->{related_resultsets} ||= {}; |
940 | my $resultsets = $self->{related_resultsets}; |
941 | if( !exists $resultsets->{$rel} ) { |
942 | #warn "fetching related resultset for rel '$rel'"; |
943 | my $rel_obj = $self->result_source->relationship_info($rel); |
944 | $self->throw_exception( |
945 | "search_related: result source '" . $self->result_source->name . |
946 | "' has no such relationship ${rel}") |
947 | unless $rel_obj; #die Dumper $self->{attrs}; |
a86b1efe |
948 | my $rs = $self->search(undef, { join => $rel }); |
949 | #if( $self->{attrs}->{cache} ) { |
950 | # $rs = $self->search(undef); |
951 | #} |
952 | #else { |
953 | #} |
64acc2bc |
954 | #use Data::Dumper; die Dumper $rs->{attrs};#$rs = $self->search( undef ); |
955 | #use Data::Dumper; warn Dumper $self->{attrs}, Dumper $rs->{attrs}; |
956 | my $alias = (defined $rs->{attrs}{seen_join}{$rel} |
957 | && $rs->{attrs}{seen_join}{$rel} > 1 |
958 | ? join('_', $rel, $rs->{attrs}{seen_join}{$rel}) |
959 | : $rel); |
960 | $resultsets->{$rel} = |
961 | $self->result_source->schema->resultset($rel_obj->{class} |
962 | )->search( undef, |
963 | { %{$rs->{attrs}}, |
964 | alias => $alias, |
965 | select => undef(), |
966 | as => undef() } |
967 | )->search(@rest); |
968 | } |
969 | return $resultsets->{$rel}; |
970 | } |
971 | |
701da8c4 |
972 | =head2 throw_exception |
973 | |
974 | See Schema's throw_exception |
975 | |
976 | =cut |
977 | |
978 | sub throw_exception { |
979 | my $self=shift; |
980 | $self->result_source->schema->throw_exception(@_); |
981 | } |
982 | |
40dbc108 |
983 | =head1 ATTRIBUTES |
076652e8 |
984 | |
a33df5d4 |
985 | The resultset takes various attributes that modify its behavior. Here's an |
986 | overview of them: |
bfab575a |
987 | |
988 | =head2 order_by |
076652e8 |
989 | |
a33df5d4 |
990 | Which column(s) to order the results by. This is currently passed through |
991 | directly to SQL, so you can give e.g. C<foo DESC> for a descending order. |
076652e8 |
992 | |
5e8b1b2a |
993 | =head2 columns |
87c4e602 |
994 | |
995 | =head3 Arguments: (arrayref) |
976f3686 |
996 | |
a33df5d4 |
997 | Shortcut to request a particular set of columns to be retrieved. Adds |
998 | C<me.> onto the start of any column without a C<.> in it and sets C<select> |
5e8b1b2a |
999 | from that, then auto-populates C<as> from C<select> as normal. (You may also |
1000 | use the C<cols> attribute, as in earlier versions of DBIC.) |
976f3686 |
1001 | |
87c4e602 |
1002 | =head2 include_columns |
1003 | |
1004 | =head3 Arguments: (arrayref) |
5ac6a044 |
1005 | |
1006 | Shortcut to include additional columns in the returned results - for example |
1007 | |
1008 | { include_columns => ['foo.name'], join => ['foo'] } |
1009 | |
1010 | would add a 'name' column to the information passed to object inflation |
1011 | |
87c4e602 |
1012 | =head2 select |
1013 | |
1014 | =head3 Arguments: (arrayref) |
976f3686 |
1015 | |
4a28c340 |
1016 | Indicates which columns should be selected from the storage. You can use |
1017 | column names, or in the case of RDBMS back ends, function or stored procedure |
1018 | names: |
1019 | |
1020 | $rs = $schema->resultset('Foo')->search( |
5e8b1b2a |
1021 | undef, |
4a28c340 |
1022 | { |
cf7b40ed |
1023 | select => [ |
4a28c340 |
1024 | 'column_name', |
1025 | { count => 'column_to_count' }, |
1026 | { sum => 'column_to_sum' } |
cf7b40ed |
1027 | ] |
4a28c340 |
1028 | } |
1029 | ); |
1030 | |
1031 | When you use function/stored procedure names and do not supply an C<as> |
1032 | attribute, the column names returned are storage-dependent. E.g. MySQL would |
1033 | return a column named C<count(column_to_count)> in the above example. |
976f3686 |
1034 | |
87c4e602 |
1035 | =head2 as |
1036 | |
1037 | =head3 Arguments: (arrayref) |
076652e8 |
1038 | |
4a28c340 |
1039 | Indicates column names for object inflation. This is used in conjunction with |
1040 | C<select>, usually when C<select> contains one or more function or stored |
1041 | procedure names: |
1042 | |
1043 | $rs = $schema->resultset('Foo')->search( |
5e8b1b2a |
1044 | undef, |
4a28c340 |
1045 | { |
cf7b40ed |
1046 | select => [ |
4a28c340 |
1047 | 'column1', |
1048 | { count => 'column2' } |
cf7b40ed |
1049 | ], |
4a28c340 |
1050 | as => [qw/ column1 column2_count /] |
1051 | } |
1052 | ); |
1053 | |
1054 | my $foo = $rs->first(); # get the first Foo |
1055 | |
1056 | If the object against which the search is performed already has an accessor |
1057 | matching a column name specified in C<as>, the value can be retrieved using |
1058 | the accessor as normal: |
1059 | |
1060 | my $column1 = $foo->column1(); |
1061 | |
1062 | If on the other hand an accessor does not exist in the object, you need to |
1063 | use C<get_column> instead: |
1064 | |
1065 | my $column2_count = $foo->get_column('column2_count'); |
1066 | |
1067 | You can create your own accessors if required - see |
1068 | L<DBIx::Class::Manual::Cookbook> for details. |
ee38fa40 |
1069 | |
bfab575a |
1070 | =head2 join |
ee38fa40 |
1071 | |
a33df5d4 |
1072 | Contains a list of relationships that should be joined for this query. For |
1073 | example: |
1074 | |
1075 | # Get CDs by Nine Inch Nails |
1076 | my $rs = $schema->resultset('CD')->search( |
1077 | { 'artist.name' => 'Nine Inch Nails' }, |
1078 | { join => 'artist' } |
1079 | ); |
1080 | |
1081 | Can also contain a hash reference to refer to the other relation's relations. |
1082 | For example: |
1083 | |
1084 | package MyApp::Schema::Track; |
1085 | use base qw/DBIx::Class/; |
1086 | __PACKAGE__->table('track'); |
1087 | __PACKAGE__->add_columns(qw/trackid cd position title/); |
1088 | __PACKAGE__->set_primary_key('trackid'); |
1089 | __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD'); |
1090 | 1; |
1091 | |
1092 | # In your application |
1093 | my $rs = $schema->resultset('Artist')->search( |
1094 | { 'track.title' => 'Teardrop' }, |
1095 | { |
1096 | join => { cd => 'track' }, |
1097 | order_by => 'artist.name', |
1098 | } |
1099 | ); |
1100 | |
2cb360cc |
1101 | If the same join is supplied twice, it will be aliased to <rel>_2 (and |
1102 | similarly for a third time). For e.g. |
1103 | |
1104 | my $rs = $schema->resultset('Artist')->search( |
1105 | { 'cds.title' => 'Foo', |
1106 | 'cds_2.title' => 'Bar' }, |
1107 | { join => [ qw/cds cds/ ] }); |
1108 | |
1109 | will return a set of all artists that have both a cd with title Foo and a cd |
1110 | with title Bar. |
1111 | |
1112 | If you want to fetch related objects from other tables as well, see C<prefetch> |
ae1c90a1 |
1113 | below. |
ee38fa40 |
1114 | |
87c4e602 |
1115 | =head2 prefetch |
1116 | |
1117 | =head3 Arguments: arrayref/hashref |
ee38fa40 |
1118 | |
ae1c90a1 |
1119 | Contains one or more relationships that should be fetched along with the main |
bfab575a |
1120 | query (when they are accessed afterwards they will have already been |
a33df5d4 |
1121 | "prefetched"). This is useful for when you know you will need the related |
ae1c90a1 |
1122 | objects, because it saves at least one query: |
1123 | |
1124 | my $rs = $schema->resultset('Tag')->search( |
5e8b1b2a |
1125 | undef, |
ae1c90a1 |
1126 | { |
1127 | prefetch => { |
1128 | cd => 'artist' |
1129 | } |
1130 | } |
1131 | ); |
1132 | |
1133 | The initial search results in SQL like the following: |
1134 | |
1135 | SELECT tag.*, cd.*, artist.* FROM tag |
1136 | JOIN cd ON tag.cd = cd.cdid |
1137 | JOIN artist ON cd.artist = artist.artistid |
1138 | |
1139 | L<DBIx::Class> has no need to go back to the database when we access the |
1140 | C<cd> or C<artist> relationships, which saves us two SQL statements in this |
1141 | case. |
1142 | |
2cb360cc |
1143 | Simple prefetches will be joined automatically, so there is no need |
1144 | for a C<join> attribute in the above search. If you're prefetching to |
1145 | depth (e.g. { cd => { artist => 'label' } or similar), you'll need to |
1146 | specify the join as well. |
ae1c90a1 |
1147 | |
1148 | C<prefetch> can be used with the following relationship types: C<belongs_to>, |
2cb360cc |
1149 | C<has_one> (or if you're using C<add_relationship>, any relationship declared |
1150 | with an accessor type of 'single' or 'filter'). |
ee38fa40 |
1151 | |
87c4e602 |
1152 | =head2 from |
1153 | |
1154 | =head3 Arguments: (arrayref) |
ee38fa40 |
1155 | |
4a28c340 |
1156 | The C<from> attribute gives you manual control over the C<FROM> clause of SQL |
1157 | statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN> |
1158 | clauses. |
ee38fa40 |
1159 | |
a33df5d4 |
1160 | NOTE: Use this on your own risk. This allows you to shoot off your foot! |
4a28c340 |
1161 | C<join> will usually do what you need and it is strongly recommended that you |
1162 | avoid using C<from> unless you cannot achieve the desired result using C<join>. |
1163 | |
1164 | In simple terms, C<from> works as follows: |
1165 | |
1166 | [ |
1167 | { <alias> => <table>, -join-type => 'inner|left|right' } |
1168 | [] # nested JOIN (optional) |
1169 | { <table.column> = <foreign_table.foreign_key> } |
1170 | ] |
1171 | |
1172 | JOIN |
1173 | <alias> <table> |
1174 | [JOIN ...] |
1175 | ON <table.column> = <foreign_table.foreign_key> |
1176 | |
1177 | An easy way to follow the examples below is to remember the following: |
1178 | |
1179 | Anything inside "[]" is a JOIN |
1180 | Anything inside "{}" is a condition for the enclosing JOIN |
1181 | |
1182 | The following examples utilize a "person" table in a family tree application. |
1183 | In order to express parent->child relationships, this table is self-joined: |
1184 | |
1185 | # Person->belongs_to('father' => 'Person'); |
1186 | # Person->belongs_to('mother' => 'Person'); |
1187 | |
1188 | C<from> can be used to nest joins. Here we return all children with a father, |
1189 | then search against all mothers of those children: |
1190 | |
1191 | $rs = $schema->resultset('Person')->search( |
5e8b1b2a |
1192 | undef, |
4a28c340 |
1193 | { |
1194 | alias => 'mother', # alias columns in accordance with "from" |
1195 | from => [ |
1196 | { mother => 'person' }, |
1197 | [ |
1198 | [ |
1199 | { child => 'person' }, |
1200 | [ |
1201 | { father => 'person' }, |
1202 | { 'father.person_id' => 'child.father_id' } |
1203 | ] |
1204 | ], |
1205 | { 'mother.person_id' => 'child.mother_id' } |
fd9f5466 |
1206 | ], |
4a28c340 |
1207 | ] |
1208 | }, |
1209 | ); |
1210 | |
1211 | # Equivalent SQL: |
1212 | # SELECT mother.* FROM person mother |
1213 | # JOIN ( |
1214 | # person child |
1215 | # JOIN person father |
1216 | # ON ( father.person_id = child.father_id ) |
1217 | # ) |
1218 | # ON ( mother.person_id = child.mother_id ) |
1219 | |
1220 | The type of any join can be controlled manually. To search against only people |
1221 | with a father in the person table, we could explicitly use C<INNER JOIN>: |
1222 | |
1223 | $rs = $schema->resultset('Person')->search( |
5e8b1b2a |
1224 | undef, |
4a28c340 |
1225 | { |
1226 | alias => 'child', # alias columns in accordance with "from" |
1227 | from => [ |
1228 | { child => 'person' }, |
1229 | [ |
1230 | { father => 'person', -join-type => 'inner' }, |
1231 | { 'father.id' => 'child.father_id' } |
1232 | ], |
1233 | ] |
1234 | }, |
1235 | ); |
1236 | |
1237 | # Equivalent SQL: |
1238 | # SELECT child.* FROM person child |
1239 | # INNER JOIN person father ON child.father_id = father.id |
ee38fa40 |
1240 | |
bfab575a |
1241 | =head2 page |
076652e8 |
1242 | |
a33df5d4 |
1243 | For a paged resultset, specifies which page to retrieve. Leave unset |
bfab575a |
1244 | for an unpaged resultset. |
076652e8 |
1245 | |
bfab575a |
1246 | =head2 rows |
076652e8 |
1247 | |
4a28c340 |
1248 | For a paged resultset, how many rows per page: |
1249 | |
1250 | rows => 10 |
1251 | |
1252 | Can also be used to simulate an SQL C<LIMIT>. |
076652e8 |
1253 | |
87c4e602 |
1254 | =head2 group_by |
1255 | |
1256 | =head3 Arguments: (arrayref) |
54540863 |
1257 | |
bda4c2b8 |
1258 | A arrayref of columns to group by. Can include columns of joined tables. |
54540863 |
1259 | |
675ce4a6 |
1260 | group_by => [qw/ column1 column2 ... /] |
1261 | |
54540863 |
1262 | =head2 distinct |
1263 | |
a33df5d4 |
1264 | Set to 1 to group by all columns. |
1265 | |
1266 | For more examples of using these attributes, see |
1267 | L<DBIx::Class::Manual::Cookbook>. |
54540863 |
1268 | |
bfab575a |
1269 | =cut |
076652e8 |
1270 | |
89c0a5a2 |
1271 | 1; |