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}}, @$include); |
223aea40 |
86 | push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include); |
5ac6a044 |
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}; |
223aea40 |
171 | $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH'; |
6009260a |
172 | |
3e0e9e27 |
173 | my $where = (@_ |
174 | ? ((@_ == 1 || ref $_[0] eq "HASH") |
175 | ? shift |
176 | : ((@_ % 2) |
177 | ? $self->throw_exception( |
178 | "Odd number of arguments to search") |
179 | : {@_})) |
180 | : undef()); |
ff7bb7a1 |
181 | if (defined $where) { |
223aea40 |
182 | $attrs->{where} = (defined $attrs->{where} |
ad3d2d7c |
183 | ? { '-and' => |
184 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
185 | $where, $attrs->{where} ] } |
0a3c5b43 |
186 | : $where); |
ff7bb7a1 |
187 | } |
0a3c5b43 |
188 | |
8839560b |
189 | if (defined $having) { |
223aea40 |
190 | $attrs->{having} = (defined $attrs->{having} |
8839560b |
191 | ? { '-and' => |
192 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
193 | $having, $attrs->{having} ] } |
194 | : $having); |
8839560b |
195 | } |
196 | |
ff7bb7a1 |
197 | $rs = (ref $self)->new($self->result_source, $attrs); |
198 | } |
199 | else { |
200 | $rs = $self; |
223aea40 |
201 | $rs->reset; |
ff7bb7a1 |
202 | } |
0a3c5b43 |
203 | return (wantarray ? $rs->all : $rs); |
204 | } |
205 | |
87f0da6a |
206 | =head2 search_literal |
207 | |
6009260a |
208 | my @obj = $rs->search_literal($literal_where_cond, @bind); |
209 | my $new_rs = $rs->search_literal($literal_where_cond, @bind); |
210 | |
211 | Pass a literal chunk of SQL to be added to the conditional part of the |
87f0da6a |
212 | resultset. |
6009260a |
213 | |
bfab575a |
214 | =cut |
fd9f5466 |
215 | |
6009260a |
216 | sub search_literal { |
217 | my ($self, $cond, @vals) = @_; |
218 | my $attrs = (ref $vals[$#vals] eq 'HASH' ? { %{ pop(@vals) } } : {}); |
219 | $attrs->{bind} = [ @{$self->{attrs}{bind}||[]}, @vals ]; |
220 | return $self->search(\$cond, $attrs); |
221 | } |
0a3c5b43 |
222 | |
87c4e602 |
223 | =head2 find |
224 | |
225 | =head3 Arguments: (@colvalues) | (\%cols, \%attrs?) |
87f0da6a |
226 | |
227 | Finds a row based on its primary key or unique constraint. For example: |
228 | |
87f0da6a |
229 | my $cd = $schema->resultset('CD')->find(5); |
230 | |
231 | Also takes an optional C<key> attribute, to search by a specific key or unique |
232 | constraint. For example: |
233 | |
fd9f5466 |
234 | my $cd = $schema->resultset('CD')->find( |
87f0da6a |
235 | { |
236 | artist => 'Massive Attack', |
237 | title => 'Mezzanine', |
238 | }, |
239 | { key => 'artist_title' } |
240 | ); |
241 | |
a33df5d4 |
242 | See also L</find_or_create> and L</update_or_create>. |
243 | |
87f0da6a |
244 | =cut |
716b3d29 |
245 | |
246 | sub find { |
247 | my ($self, @vals) = @_; |
248 | my $attrs = (@vals > 1 && ref $vals[$#vals] eq 'HASH' ? pop(@vals) : {}); |
87f0da6a |
249 | |
701da8c4 |
250 | my @cols = $self->result_source->primary_columns; |
87f0da6a |
251 | if (exists $attrs->{key}) { |
701da8c4 |
252 | my %uniq = $self->result_source->unique_constraints; |
223aea40 |
253 | $self->throw_exception( "Unknown key $attrs->{key} on $self->name" ) |
87f0da6a |
254 | unless exists $uniq{$attrs->{key}}; |
255 | @cols = @{ $uniq{$attrs->{key}} }; |
256 | } |
257 | #use Data::Dumper; warn Dumper($attrs, @vals, @cols); |
701da8c4 |
258 | $self->throw_exception( "Can't find unless a primary key or unique constraint is defined" ) |
87f0da6a |
259 | unless @cols; |
260 | |
716b3d29 |
261 | my $query; |
262 | if (ref $vals[0] eq 'HASH') { |
01bc091e |
263 | $query = { %{$vals[0]} }; |
87f0da6a |
264 | } elsif (@cols == @vals) { |
716b3d29 |
265 | $query = {}; |
87f0da6a |
266 | @{$query}{@cols} = @vals; |
716b3d29 |
267 | } else { |
268 | $query = {@vals}; |
269 | } |
223aea40 |
270 | foreach my $key (grep { ! m/\./ } keys %$query) { |
271 | $query->{"$self->{attrs}{alias}.$key"} = delete $query->{$key}; |
01bc091e |
272 | } |
716b3d29 |
273 | #warn Dumper($query); |
8389d433 |
274 | |
275 | if (keys %$attrs) { |
276 | my $rs = $self->search($query,$attrs); |
277 | return keys %{$rs->{collapse}} ? $rs->next : $rs->single; |
278 | } else { |
279 | return keys %{$self->{collapse}} ? $self->search($query)->next : $self->single($query); |
280 | } |
716b3d29 |
281 | } |
282 | |
b52e9bf8 |
283 | =head2 search_related |
284 | |
285 | $rs->search_related('relname', $cond?, $attrs?); |
286 | |
a33df5d4 |
287 | Search the specified relationship. Optionally specify a condition for matching |
288 | records. |
289 | |
b52e9bf8 |
290 | =cut |
291 | |
6aeb9185 |
292 | sub search_related { |
64acc2bc |
293 | return shift->related_resultset(shift)->search(@_); |
6aeb9185 |
294 | } |
b52e9bf8 |
295 | |
bfab575a |
296 | =head2 cursor |
ee38fa40 |
297 | |
bfab575a |
298 | Returns a storage-driven cursor to the given resultset. |
ee38fa40 |
299 | |
300 | =cut |
301 | |
73f58123 |
302 | sub cursor { |
303 | my ($self) = @_; |
223aea40 |
304 | my $attrs = { %{$self->{attrs}} }; |
73f58123 |
305 | return $self->{cursor} |
701da8c4 |
306 | ||= $self->result_source->storage->select($self->{from}, $attrs->{select}, |
73f58123 |
307 | $attrs->{where},$attrs); |
308 | } |
309 | |
a04ab285 |
310 | =head2 single |
311 | |
312 | Inflates the first result without creating a cursor |
313 | |
314 | =cut |
315 | |
316 | sub single { |
223aea40 |
317 | my ($self, $where) = @_; |
318 | my $attrs = { %{$self->{attrs}} }; |
319 | if ($where) { |
a04ab285 |
320 | if (defined $attrs->{where}) { |
321 | $attrs->{where} = { |
223aea40 |
322 | '-and' => |
323 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
324 | $where, delete $attrs->{where} ] |
a04ab285 |
325 | }; |
326 | } else { |
223aea40 |
327 | $attrs->{where} = $where; |
a04ab285 |
328 | } |
329 | } |
330 | my @data = $self->result_source->storage->select_single( |
331 | $self->{from}, $attrs->{select}, |
332 | $attrs->{where},$attrs); |
333 | return (@data ? $self->_construct_object(@data) : ()); |
334 | } |
335 | |
336 | |
87f0da6a |
337 | =head2 search_like |
338 | |
a33df5d4 |
339 | Perform a search, but use C<LIKE> instead of equality as the condition. Note |
340 | that this is simply a convenience method; you most likely want to use |
341 | L</search> with specific operators. |
342 | |
343 | For more information, see L<DBIx::Class::Manual::Cookbook>. |
87f0da6a |
344 | |
345 | =cut |
58a4bd18 |
346 | |
347 | sub search_like { |
223aea40 |
348 | my $class = shift; |
349 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
350 | my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_}; |
58a4bd18 |
351 | $query->{$_} = { 'like' => $query->{$_} } for keys %$query; |
352 | return $class->search($query, { %$attrs }); |
353 | } |
354 | |
87c4e602 |
355 | =head2 slice |
356 | |
357 | =head3 Arguments: ($first, $last) |
ee38fa40 |
358 | |
bfab575a |
359 | Returns a subset of elements from the resultset. |
ee38fa40 |
360 | |
361 | =cut |
362 | |
89c0a5a2 |
363 | sub slice { |
364 | my ($self, $min, $max) = @_; |
365 | my $attrs = { %{ $self->{attrs} || {} } }; |
6aeb9185 |
366 | $attrs->{offset} ||= 0; |
367 | $attrs->{offset} += $min; |
89c0a5a2 |
368 | $attrs->{rows} = ($max ? ($max - $min + 1) : 1); |
701da8c4 |
369 | my $slice = (ref $self)->new($self->result_source, $attrs); |
89c0a5a2 |
370 | return (wantarray ? $slice->all : $slice); |
371 | } |
372 | |
87f0da6a |
373 | =head2 next |
ee38fa40 |
374 | |
a33df5d4 |
375 | Returns the next element in the resultset (C<undef> is there is none). |
376 | |
377 | Can be used to efficiently iterate over records in the resultset: |
378 | |
5e8b1b2a |
379 | my $rs = $schema->resultset('CD')->search; |
a33df5d4 |
380 | while (my $cd = $rs->next) { |
381 | print $cd->title; |
382 | } |
ee38fa40 |
383 | |
384 | =cut |
385 | |
89c0a5a2 |
386 | sub next { |
387 | my ($self) = @_; |
223aea40 |
388 | if (@{$self->{all_cache} || []}) { |
64acc2bc |
389 | $self->{all_cache_position} ||= 0; |
223aea40 |
390 | return $self->{all_cache}->[$self->{all_cache_position}++]; |
64acc2bc |
391 | } |
3e0e9e27 |
392 | if ($self->{attrs}{cache}) { |
0f66a01b |
393 | $self->{all_cache_position} = 1; |
3e0e9e27 |
394 | return ($self->all)[0]; |
395 | } |
0f66a01b |
396 | my @row = (exists $self->{stashed_row} |
397 | ? @{delete $self->{stashed_row}} |
398 | : $self->cursor->next); |
a953d8d9 |
399 | # warn Dumper(\@row); use Data::Dumper; |
89c0a5a2 |
400 | return unless (@row); |
c7ce65e6 |
401 | return $self->_construct_object(@row); |
402 | } |
403 | |
404 | sub _construct_object { |
405 | my ($self, @row) = @_; |
b3e8ac9b |
406 | my @as = @{ $self->{attrs}{as} }; |
223aea40 |
407 | |
0f66a01b |
408 | my $info = $self->_collapse_result(\@as, \@row); |
223aea40 |
409 | |
a50bcd52 |
410 | my $new = $self->result_class->inflate_result($self->result_source, @$info); |
223aea40 |
411 | |
33ce49d6 |
412 | $new = $self->{attrs}{record_filter}->($new) |
413 | if exists $self->{attrs}{record_filter}; |
414 | return $new; |
89c0a5a2 |
415 | } |
416 | |
0f66a01b |
417 | sub _collapse_result { |
418 | my ($self, $as, $row, $prefix) = @_; |
419 | |
420 | my %const; |
421 | |
422 | my @copy = @$row; |
5a5bec6c |
423 | foreach my $this_as (@$as) { |
424 | my $val = shift @copy; |
425 | if (defined $prefix) { |
426 | if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) { |
427 | my $remain = $1; |
223aea40 |
428 | $remain =~ /^(?:(.*)\.)?([^.]+)$/; |
5a5bec6c |
429 | $const{$1||''}{$2} = $val; |
430 | } |
431 | } else { |
223aea40 |
432 | $this_as =~ /^(?:(.*)\.)?([^.]+)$/; |
5a5bec6c |
433 | $const{$1||''}{$2} = $val; |
0f66a01b |
434 | } |
0f66a01b |
435 | } |
436 | |
0f66a01b |
437 | my $info = [ {}, {} ]; |
438 | foreach my $key (keys %const) { |
439 | if (length $key) { |
440 | my $target = $info; |
441 | my @parts = split(/\./, $key); |
442 | foreach my $p (@parts) { |
443 | $target = $target->[1]->{$p} ||= []; |
444 | } |
445 | $target->[0] = $const{$key}; |
446 | } else { |
447 | $info->[0] = $const{$key}; |
448 | } |
449 | } |
450 | |
5a5bec6c |
451 | my @collapse = (defined($prefix) |
452 | ? (map { (m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()); } |
453 | keys %{$self->{collapse}}) |
454 | : keys %{$self->{collapse}}); |
455 | if (@collapse) { |
456 | my ($c) = sort { length $a <=> length $b } @collapse; |
0f66a01b |
457 | my $target = $info; |
0f66a01b |
458 | foreach my $p (split(/\./, $c)) { |
5a5bec6c |
459 | $target = $target->[1]->{$p} ||= []; |
0f66a01b |
460 | } |
5a5bec6c |
461 | my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c); |
462 | my @co_key = @{$self->{collapse}{$c_prefix}}; |
0f66a01b |
463 | my %co_check = map { ($_, $target->[0]->{$_}); } @co_key; |
5a5bec6c |
464 | my $tree = $self->_collapse_result($as, $row, $c_prefix); |
0f66a01b |
465 | my (@final, @raw); |
5a5bec6c |
466 | while ( !(grep { |
467 | !defined($tree->[0]->{$_}) |
468 | || $co_check{$_} ne $tree->[0]->{$_} |
469 | } @co_key) ) { |
0f66a01b |
470 | push(@final, $tree); |
471 | last unless (@raw = $self->cursor->next); |
472 | $row = $self->{stashed_row} = \@raw; |
5a5bec6c |
473 | $tree = $self->_collapse_result($as, $row, $c_prefix); |
474 | #warn Data::Dumper::Dumper($tree, $row); |
0f66a01b |
475 | } |
223aea40 |
476 | @$target = @final; |
0f66a01b |
477 | } |
478 | |
0f66a01b |
479 | return $info; |
480 | } |
481 | |
87c4e602 |
482 | =head2 result_source |
701da8c4 |
483 | |
484 | Returns a reference to the result source for this recordset. |
485 | |
486 | =cut |
487 | |
488 | |
bfab575a |
489 | =head2 count |
ee38fa40 |
490 | |
bfab575a |
491 | Performs an SQL C<COUNT> with the same query as the resultset was built |
6009260a |
492 | with to find the number of elements. If passed arguments, does a search |
493 | on the resultset and counts the results of that. |
ee38fa40 |
494 | |
bda4c2b8 |
495 | Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY> |
496 | using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do |
497 | not support C<DISTINCT> with multiple columns. If you are using such a |
498 | database, you should only use columns from the main table in your C<group_by> |
499 | clause. |
500 | |
ee38fa40 |
501 | =cut |
502 | |
89c0a5a2 |
503 | sub count { |
6009260a |
504 | my $self = shift; |
223aea40 |
505 | return $self->search(@_)->count if @_ and defined $_[0]; |
6aeb9185 |
506 | unless (defined $self->{count}) { |
223aea40 |
507 | return scalar @{ $self->get_cache } if @{ $self->get_cache }; |
508 | my $select = { count => '*' }; |
8839560b |
509 | my $attrs = { %{ $self->{attrs} } }; |
223aea40 |
510 | if (my $group_by = delete $attrs->{group_by}) { |
8839560b |
511 | delete $attrs->{having}; |
dec2517f |
512 | my @distinct = (ref $group_by ? @$group_by : ($group_by)); |
15c382be |
513 | # todo: try CONCAT for multi-column pk |
514 | my @pk = $self->result_source->primary_columns; |
223aea40 |
515 | if (@pk == 1) { |
516 | foreach my $column (@distinct) { |
517 | if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) { |
518 | @distinct = ($column); |
15c382be |
519 | last; |
520 | } |
521 | } |
522 | } |
523 | |
223aea40 |
524 | $select = { count => { distinct => \@distinct } }; |
15c382be |
525 | #use Data::Dumper; die Dumper $select; |
526 | } |
527 | |
8839560b |
528 | $attrs->{select} = $select; |
223aea40 |
529 | $attrs->{as} = [qw/count/]; |
ea20d0fd |
530 | # offset, order by and page are not needed to count. record_filter is cdbi |
531 | delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/; |
3c5b25c5 |
532 | |
701da8c4 |
533 | ($self->{count}) = (ref $self)->new($self->result_source, $attrs)->cursor->next; |
3c5b25c5 |
534 | } |
535 | return 0 unless $self->{count}; |
6aeb9185 |
536 | my $count = $self->{count}; |
537 | $count -= $self->{attrs}{offset} if $self->{attrs}{offset}; |
538 | $count = $self->{attrs}{rows} if |
223aea40 |
539 | $self->{attrs}{rows} and $self->{attrs}{rows} < $count; |
6aeb9185 |
540 | return $count; |
89c0a5a2 |
541 | } |
542 | |
bfab575a |
543 | =head2 count_literal |
6009260a |
544 | |
a33df5d4 |
545 | Calls L</search_literal> with the passed arguments, then L</count>. |
6009260a |
546 | |
547 | =cut |
548 | |
549 | sub count_literal { shift->search_literal(@_)->count; } |
550 | |
bfab575a |
551 | =head2 all |
ee38fa40 |
552 | |
bfab575a |
553 | Returns all elements in the resultset. Called implictly if the resultset |
554 | is returned in list context. |
ee38fa40 |
555 | |
556 | =cut |
557 | |
89c0a5a2 |
558 | sub all { |
559 | my ($self) = @_; |
223aea40 |
560 | return @{ $self->get_cache } if @{ $self->get_cache }; |
5a5bec6c |
561 | |
562 | my @obj; |
563 | |
564 | if (keys %{$self->{collapse}}) { |
565 | # Using $self->cursor->all is really just an optimisation. |
566 | # If we're collapsing has_many prefetches it probably makes |
567 | # very little difference, and this is cleaner than hacking |
568 | # _construct_object to survive the approach |
569 | my @row; |
570 | $self->cursor->reset; |
571 | while (@row = $self->cursor->next) { |
572 | push(@obj, $self->_construct_object(@row)); |
573 | } |
574 | } else { |
223aea40 |
575 | @obj = map { $self->_construct_object(@$_) } $self->cursor->all; |
64acc2bc |
576 | } |
5a5bec6c |
577 | |
223aea40 |
578 | $self->set_cache(\@obj) if $self->{attrs}{cache}; |
5a5bec6c |
579 | return @obj; |
89c0a5a2 |
580 | } |
581 | |
bfab575a |
582 | =head2 reset |
ee38fa40 |
583 | |
bfab575a |
584 | Resets the resultset's cursor, so you can iterate through the elements again. |
ee38fa40 |
585 | |
586 | =cut |
587 | |
89c0a5a2 |
588 | sub reset { |
589 | my ($self) = @_; |
64acc2bc |
590 | $self->{all_cache_position} = 0; |
73f58123 |
591 | $self->cursor->reset; |
89c0a5a2 |
592 | return $self; |
593 | } |
594 | |
bfab575a |
595 | =head2 first |
ee38fa40 |
596 | |
bfab575a |
597 | Resets the resultset and returns the first element. |
ee38fa40 |
598 | |
599 | =cut |
600 | |
89c0a5a2 |
601 | sub first { |
602 | return $_[0]->reset->next; |
603 | } |
604 | |
87c4e602 |
605 | =head2 update |
606 | |
607 | =head3 Arguments: (\%values) |
c01ab172 |
608 | |
a33df5d4 |
609 | Sets the specified columns in the resultset to the supplied values. |
c01ab172 |
610 | |
611 | =cut |
612 | |
613 | sub update { |
614 | my ($self, $values) = @_; |
701da8c4 |
615 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
616 | return $self->result_source->storage->update( |
617 | $self->result_source->from, $values, $self->{cond}); |
c01ab172 |
618 | } |
619 | |
87c4e602 |
620 | =head2 update_all |
621 | |
622 | =head3 Arguments: (\%values) |
c01ab172 |
623 | |
a33df5d4 |
624 | Fetches all objects and updates them one at a time. Note that C<update_all> |
625 | will run cascade triggers while L</update> will not. |
c01ab172 |
626 | |
627 | =cut |
628 | |
629 | sub update_all { |
630 | my ($self, $values) = @_; |
701da8c4 |
631 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
c01ab172 |
632 | foreach my $obj ($self->all) { |
633 | $obj->set_columns($values)->update; |
634 | } |
635 | return 1; |
636 | } |
637 | |
bfab575a |
638 | =head2 delete |
ee38fa40 |
639 | |
c01ab172 |
640 | Deletes the contents of the resultset from its result source. |
ee38fa40 |
641 | |
642 | =cut |
643 | |
28927b50 |
644 | sub delete { |
89c0a5a2 |
645 | my ($self) = @_; |
ca4b5ab7 |
646 | my $del = {}; |
647 | $self->throw_exception("Can't delete on resultset with condition unless hash or array") |
648 | unless (ref($self->{cond}) eq 'HASH' || ref($self->{cond}) eq 'ARRAY'); |
649 | if (ref $self->{cond} eq 'ARRAY') { |
650 | $del = [ map { my %hash; |
651 | foreach my $key (keys %{$_}) { |
223aea40 |
652 | $key =~ /([^.]+)$/; |
ca4b5ab7 |
653 | $hash{$1} = $_->{$key}; |
654 | }; \%hash; } @{$self->{cond}} ]; |
655 | } elsif ((keys %{$self->{cond}})[0] eq '-and') { |
656 | $del->{-and} = [ map { my %hash; |
657 | foreach my $key (keys %{$_}) { |
223aea40 |
658 | $key =~ /([^.]+)$/; |
ca4b5ab7 |
659 | $hash{$1} = $_->{$key}; |
660 | }; \%hash; } @{$self->{cond}{-and}} ]; |
661 | } else { |
662 | foreach my $key (keys %{$self->{cond}}) { |
223aea40 |
663 | $key =~ /([^.]+)$/; |
ca4b5ab7 |
664 | $del->{$1} = $self->{cond}{$key}; |
665 | } |
666 | } |
667 | $self->result_source->storage->delete($self->result_source->from, $del); |
89c0a5a2 |
668 | return 1; |
669 | } |
670 | |
c01ab172 |
671 | =head2 delete_all |
672 | |
a33df5d4 |
673 | Fetches all objects and deletes them one at a time. Note that C<delete_all> |
674 | will run cascade triggers while L</delete> will not. |
c01ab172 |
675 | |
676 | =cut |
677 | |
678 | sub delete_all { |
679 | my ($self) = @_; |
680 | $_->delete for $self->all; |
681 | return 1; |
682 | } |
28927b50 |
683 | |
bfab575a |
684 | =head2 pager |
ee38fa40 |
685 | |
686 | Returns a L<Data::Page> object for the current resultset. Only makes |
a33df5d4 |
687 | sense for queries with a C<page> attribute. |
ee38fa40 |
688 | |
689 | =cut |
690 | |
3c5b25c5 |
691 | sub pager { |
692 | my ($self) = @_; |
693 | my $attrs = $self->{attrs}; |
701da8c4 |
694 | $self->throw_exception("Can't create pager for non-paged rs") unless $self->{page}; |
6aeb9185 |
695 | $attrs->{rows} ||= 10; |
696 | $self->count; |
697 | return $self->{pager} ||= Data::Page->new( |
93b004d3 |
698 | $self->{count}, $attrs->{rows}, $self->{page}); |
3c5b25c5 |
699 | } |
700 | |
87c4e602 |
701 | =head2 page |
702 | |
703 | =head3 Arguments: ($page_num) |
ee38fa40 |
704 | |
bfab575a |
705 | Returns a new resultset for the specified page. |
ee38fa40 |
706 | |
707 | =cut |
708 | |
3c5b25c5 |
709 | sub page { |
710 | my ($self, $page) = @_; |
6aeb9185 |
711 | my $attrs = { %{$self->{attrs}} }; |
3c5b25c5 |
712 | $attrs->{page} = $page; |
701da8c4 |
713 | return (ref $self)->new($self->result_source, $attrs); |
fea3d045 |
714 | } |
715 | |
87c4e602 |
716 | =head2 new_result |
717 | |
718 | =head3 Arguments: (\%vals) |
fea3d045 |
719 | |
87f0da6a |
720 | Creates a result in the resultset's result class. |
fea3d045 |
721 | |
722 | =cut |
723 | |
724 | sub new_result { |
725 | my ($self, $values) = @_; |
701da8c4 |
726 | $self->throw_exception( "new_result needs a hash" ) |
fea3d045 |
727 | unless (ref $values eq 'HASH'); |
701da8c4 |
728 | $self->throw_exception( "Can't abstract implicit construct, condition not a hash" ) |
fea3d045 |
729 | if ($self->{cond} && !(ref $self->{cond} eq 'HASH')); |
730 | my %new = %$values; |
731 | my $alias = $self->{attrs}{alias}; |
732 | foreach my $key (keys %{$self->{cond}||{}}) { |
223aea40 |
733 | $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/); |
fea3d045 |
734 | } |
a50bcd52 |
735 | my $obj = $self->result_class->new(\%new); |
701da8c4 |
736 | $obj->result_source($self->result_source) if $obj->can('result_source'); |
223aea40 |
737 | return $obj; |
fea3d045 |
738 | } |
739 | |
87c4e602 |
740 | =head2 create |
741 | |
742 | =head3 Arguments: (\%vals) |
fea3d045 |
743 | |
87f0da6a |
744 | Inserts a record into the resultset and returns the object. |
fea3d045 |
745 | |
a33df5d4 |
746 | Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. |
fea3d045 |
747 | |
748 | =cut |
749 | |
750 | sub create { |
751 | my ($self, $attrs) = @_; |
701da8c4 |
752 | $self->throw_exception( "create needs a hashref" ) unless ref $attrs eq 'HASH'; |
fea3d045 |
753 | return $self->new_result($attrs)->insert; |
3c5b25c5 |
754 | } |
755 | |
87c4e602 |
756 | =head2 find_or_create |
757 | |
758 | =head3 Arguments: (\%vals, \%attrs?) |
87f0da6a |
759 | |
760 | $class->find_or_create({ key => $val, ... }); |
c2b15ecc |
761 | |
fd9f5466 |
762 | Searches for a record matching the search condition; if it doesn't find one, |
763 | creates one and returns that instead. |
87f0da6a |
764 | |
87f0da6a |
765 | my $cd = $schema->resultset('CD')->find_or_create({ |
766 | cdid => 5, |
767 | artist => 'Massive Attack', |
768 | title => 'Mezzanine', |
769 | year => 2005, |
770 | }); |
771 | |
772 | Also takes an optional C<key> attribute, to search by a specific key or unique |
773 | constraint. For example: |
774 | |
775 | my $cd = $schema->resultset('CD')->find_or_create( |
776 | { |
777 | artist => 'Massive Attack', |
778 | title => 'Mezzanine', |
779 | }, |
780 | { key => 'artist_title' } |
781 | ); |
782 | |
783 | See also L</find> and L</update_or_create>. |
784 | |
c2b15ecc |
785 | =cut |
786 | |
787 | sub find_or_create { |
788 | my $self = shift; |
87f0da6a |
789 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
223aea40 |
790 | my $hash = ref $_[0] eq 'HASH' ? shift : {@_}; |
87f0da6a |
791 | my $exists = $self->find($hash, $attrs); |
223aea40 |
792 | return defined $exists ? $exists : $self->create($hash); |
c2b15ecc |
793 | } |
794 | |
87f0da6a |
795 | =head2 update_or_create |
796 | |
797 | $class->update_or_create({ key => $val, ... }); |
798 | |
799 | First, search for an existing row matching one of the unique constraints |
800 | (including the primary key) on the source of this resultset. If a row is |
801 | found, update it with the other given column values. Otherwise, create a new |
802 | row. |
803 | |
804 | Takes an optional C<key> attribute to search on a specific unique constraint. |
805 | For example: |
806 | |
807 | # In your application |
808 | my $cd = $schema->resultset('CD')->update_or_create( |
809 | { |
810 | artist => 'Massive Attack', |
811 | title => 'Mezzanine', |
812 | year => 1998, |
813 | }, |
814 | { key => 'artist_title' } |
815 | ); |
816 | |
817 | If no C<key> is specified, it searches on all unique constraints defined on the |
818 | source, including the primary key. |
819 | |
820 | If the C<key> is specified as C<primary>, search only on the primary key. |
821 | |
a33df5d4 |
822 | See also L</find> and L</find_or_create>. |
823 | |
87f0da6a |
824 | =cut |
825 | |
826 | sub update_or_create { |
827 | my $self = shift; |
87f0da6a |
828 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
223aea40 |
829 | my $hash = ref $_[0] eq 'HASH' ? shift : {@_}; |
87f0da6a |
830 | |
701da8c4 |
831 | my %unique_constraints = $self->result_source->unique_constraints; |
87f0da6a |
832 | my @constraint_names = (exists $attrs->{key} |
833 | ? ($attrs->{key}) |
834 | : keys %unique_constraints); |
835 | |
836 | my @unique_hashes; |
837 | foreach my $name (@constraint_names) { |
838 | my @unique_cols = @{ $unique_constraints{$name} }; |
839 | my %unique_hash = |
840 | map { $_ => $hash->{$_} } |
841 | grep { exists $hash->{$_} } |
842 | @unique_cols; |
843 | |
844 | push @unique_hashes, \%unique_hash |
845 | if (scalar keys %unique_hash == scalar @unique_cols); |
846 | } |
847 | |
87f0da6a |
848 | if (@unique_hashes) { |
223aea40 |
849 | my $row = $self->single(\@unique_hashes); |
850 | if (defined $row) { |
87f0da6a |
851 | $row->set_columns($hash); |
852 | $row->update; |
223aea40 |
853 | return $row; |
87f0da6a |
854 | } |
855 | } |
856 | |
223aea40 |
857 | return $self->create($hash); |
87f0da6a |
858 | } |
859 | |
64acc2bc |
860 | =head2 get_cache |
861 | |
862 | Gets the contents of the cache for the resultset. |
863 | |
864 | =cut |
865 | |
866 | sub get_cache { |
223aea40 |
867 | shift->{all_cache} || []; |
64acc2bc |
868 | } |
869 | |
870 | =head2 set_cache |
871 | |
872 | Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset. |
873 | |
874 | =cut |
875 | |
876 | sub set_cache { |
877 | my ( $self, $data ) = @_; |
878 | $self->throw_exception("set_cache requires an arrayref") |
879 | if ref $data ne 'ARRAY'; |
a50bcd52 |
880 | my $result_class = $self->result_class; |
64acc2bc |
881 | foreach( @$data ) { |
882 | $self->throw_exception("cannot cache object of type '$_', expected '$result_class'") |
883 | if ref $_ ne $result_class; |
884 | } |
885 | $self->{all_cache} = $data; |
886 | } |
887 | |
888 | =head2 clear_cache |
889 | |
890 | Clears the cache for the resultset. |
891 | |
892 | =cut |
893 | |
894 | sub clear_cache { |
223aea40 |
895 | shift->set_cache([]); |
64acc2bc |
896 | } |
897 | |
898 | =head2 related_resultset |
899 | |
900 | Returns a related resultset for the supplied relationship name. |
901 | |
902 | $rs = $rs->related_resultset('foo'); |
903 | |
904 | =cut |
905 | |
906 | sub related_resultset { |
907 | my ( $self, $rel, @rest ) = @_; |
908 | $self->{related_resultsets} ||= {}; |
223aea40 |
909 | return $self->{related_resultsets}{$rel} ||= do { |
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 | |
917 | my $rs = $self->search(undef, { join => $rel }); |
918 | my $alias = defined $rs->{attrs}{seen_join}{$rel} |
919 | && $rs->{attrs}{seen_join}{$rel} > 1 |
920 | ? join('_', $rel, $rs->{attrs}{seen_join}{$rel}) |
921 | : $rel; |
922 | |
64acc2bc |
923 | $self->result_source->schema->resultset($rel_obj->{class} |
924 | )->search( undef, |
925 | { %{$rs->{attrs}}, |
926 | alias => $alias, |
223aea40 |
927 | select => undef, |
928 | as => undef } |
929 | )->search(@rest); |
930 | }; |
64acc2bc |
931 | } |
932 | |
701da8c4 |
933 | =head2 throw_exception |
934 | |
935 | See Schema's throw_exception |
936 | |
937 | =cut |
938 | |
939 | sub throw_exception { |
940 | my $self=shift; |
941 | $self->result_source->schema->throw_exception(@_); |
942 | } |
943 | |
40dbc108 |
944 | =head1 ATTRIBUTES |
076652e8 |
945 | |
a33df5d4 |
946 | The resultset takes various attributes that modify its behavior. Here's an |
947 | overview of them: |
bfab575a |
948 | |
949 | =head2 order_by |
076652e8 |
950 | |
a33df5d4 |
951 | Which column(s) to order the results by. This is currently passed through |
952 | directly to SQL, so you can give e.g. C<foo DESC> for a descending order. |
076652e8 |
953 | |
5e8b1b2a |
954 | =head2 columns |
87c4e602 |
955 | |
956 | =head3 Arguments: (arrayref) |
976f3686 |
957 | |
a33df5d4 |
958 | Shortcut to request a particular set of columns to be retrieved. Adds |
959 | C<me.> onto the start of any column without a C<.> in it and sets C<select> |
5e8b1b2a |
960 | from that, then auto-populates C<as> from C<select> as normal. (You may also |
961 | use the C<cols> attribute, as in earlier versions of DBIC.) |
976f3686 |
962 | |
87c4e602 |
963 | =head2 include_columns |
964 | |
965 | =head3 Arguments: (arrayref) |
5ac6a044 |
966 | |
967 | Shortcut to include additional columns in the returned results - for example |
968 | |
969 | { include_columns => ['foo.name'], join => ['foo'] } |
970 | |
971 | would add a 'name' column to the information passed to object inflation |
972 | |
87c4e602 |
973 | =head2 select |
974 | |
975 | =head3 Arguments: (arrayref) |
976f3686 |
976 | |
4a28c340 |
977 | Indicates which columns should be selected from the storage. You can use |
978 | column names, or in the case of RDBMS back ends, function or stored procedure |
979 | names: |
980 | |
981 | $rs = $schema->resultset('Foo')->search( |
5e8b1b2a |
982 | undef, |
4a28c340 |
983 | { |
cf7b40ed |
984 | select => [ |
4a28c340 |
985 | 'column_name', |
986 | { count => 'column_to_count' }, |
987 | { sum => 'column_to_sum' } |
cf7b40ed |
988 | ] |
4a28c340 |
989 | } |
990 | ); |
991 | |
992 | When you use function/stored procedure names and do not supply an C<as> |
993 | attribute, the column names returned are storage-dependent. E.g. MySQL would |
994 | return a column named C<count(column_to_count)> in the above example. |
976f3686 |
995 | |
87c4e602 |
996 | =head2 as |
997 | |
998 | =head3 Arguments: (arrayref) |
076652e8 |
999 | |
4a28c340 |
1000 | Indicates column names for object inflation. This is used in conjunction with |
1001 | C<select>, usually when C<select> contains one or more function or stored |
1002 | procedure names: |
1003 | |
1004 | $rs = $schema->resultset('Foo')->search( |
5e8b1b2a |
1005 | undef, |
4a28c340 |
1006 | { |
cf7b40ed |
1007 | select => [ |
4a28c340 |
1008 | 'column1', |
1009 | { count => 'column2' } |
cf7b40ed |
1010 | ], |
4a28c340 |
1011 | as => [qw/ column1 column2_count /] |
1012 | } |
1013 | ); |
1014 | |
1015 | my $foo = $rs->first(); # get the first Foo |
1016 | |
1017 | If the object against which the search is performed already has an accessor |
1018 | matching a column name specified in C<as>, the value can be retrieved using |
1019 | the accessor as normal: |
1020 | |
1021 | my $column1 = $foo->column1(); |
1022 | |
1023 | If on the other hand an accessor does not exist in the object, you need to |
1024 | use C<get_column> instead: |
1025 | |
1026 | my $column2_count = $foo->get_column('column2_count'); |
1027 | |
1028 | You can create your own accessors if required - see |
1029 | L<DBIx::Class::Manual::Cookbook> for details. |
ee38fa40 |
1030 | |
bfab575a |
1031 | =head2 join |
ee38fa40 |
1032 | |
a33df5d4 |
1033 | Contains a list of relationships that should be joined for this query. For |
1034 | example: |
1035 | |
1036 | # Get CDs by Nine Inch Nails |
1037 | my $rs = $schema->resultset('CD')->search( |
1038 | { 'artist.name' => 'Nine Inch Nails' }, |
1039 | { join => 'artist' } |
1040 | ); |
1041 | |
1042 | Can also contain a hash reference to refer to the other relation's relations. |
1043 | For example: |
1044 | |
1045 | package MyApp::Schema::Track; |
1046 | use base qw/DBIx::Class/; |
1047 | __PACKAGE__->table('track'); |
1048 | __PACKAGE__->add_columns(qw/trackid cd position title/); |
1049 | __PACKAGE__->set_primary_key('trackid'); |
1050 | __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD'); |
1051 | 1; |
1052 | |
1053 | # In your application |
1054 | my $rs = $schema->resultset('Artist')->search( |
1055 | { 'track.title' => 'Teardrop' }, |
1056 | { |
1057 | join => { cd => 'track' }, |
1058 | order_by => 'artist.name', |
1059 | } |
1060 | ); |
1061 | |
2cb360cc |
1062 | If the same join is supplied twice, it will be aliased to <rel>_2 (and |
1063 | similarly for a third time). For e.g. |
1064 | |
1065 | my $rs = $schema->resultset('Artist')->search( |
1066 | { 'cds.title' => 'Foo', |
1067 | 'cds_2.title' => 'Bar' }, |
1068 | { join => [ qw/cds cds/ ] }); |
1069 | |
1070 | will return a set of all artists that have both a cd with title Foo and a cd |
1071 | with title Bar. |
1072 | |
1073 | If you want to fetch related objects from other tables as well, see C<prefetch> |
ae1c90a1 |
1074 | below. |
ee38fa40 |
1075 | |
87c4e602 |
1076 | =head2 prefetch |
1077 | |
1078 | =head3 Arguments: arrayref/hashref |
ee38fa40 |
1079 | |
ae1c90a1 |
1080 | Contains one or more relationships that should be fetched along with the main |
bfab575a |
1081 | query (when they are accessed afterwards they will have already been |
a33df5d4 |
1082 | "prefetched"). This is useful for when you know you will need the related |
ae1c90a1 |
1083 | objects, because it saves at least one query: |
1084 | |
1085 | my $rs = $schema->resultset('Tag')->search( |
5e8b1b2a |
1086 | undef, |
ae1c90a1 |
1087 | { |
1088 | prefetch => { |
1089 | cd => 'artist' |
1090 | } |
1091 | } |
1092 | ); |
1093 | |
1094 | The initial search results in SQL like the following: |
1095 | |
1096 | SELECT tag.*, cd.*, artist.* FROM tag |
1097 | JOIN cd ON tag.cd = cd.cdid |
1098 | JOIN artist ON cd.artist = artist.artistid |
1099 | |
1100 | L<DBIx::Class> has no need to go back to the database when we access the |
1101 | C<cd> or C<artist> relationships, which saves us two SQL statements in this |
1102 | case. |
1103 | |
2cb360cc |
1104 | Simple prefetches will be joined automatically, so there is no need |
1105 | for a C<join> attribute in the above search. If you're prefetching to |
1106 | depth (e.g. { cd => { artist => 'label' } or similar), you'll need to |
1107 | specify the join as well. |
ae1c90a1 |
1108 | |
1109 | C<prefetch> can be used with the following relationship types: C<belongs_to>, |
2cb360cc |
1110 | C<has_one> (or if you're using C<add_relationship>, any relationship declared |
1111 | with an accessor type of 'single' or 'filter'). |
ee38fa40 |
1112 | |
87c4e602 |
1113 | =head2 from |
1114 | |
1115 | =head3 Arguments: (arrayref) |
ee38fa40 |
1116 | |
4a28c340 |
1117 | The C<from> attribute gives you manual control over the C<FROM> clause of SQL |
1118 | statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN> |
1119 | clauses. |
ee38fa40 |
1120 | |
a33df5d4 |
1121 | NOTE: Use this on your own risk. This allows you to shoot off your foot! |
4a28c340 |
1122 | C<join> will usually do what you need and it is strongly recommended that you |
1123 | avoid using C<from> unless you cannot achieve the desired result using C<join>. |
1124 | |
1125 | In simple terms, C<from> works as follows: |
1126 | |
1127 | [ |
1128 | { <alias> => <table>, -join-type => 'inner|left|right' } |
1129 | [] # nested JOIN (optional) |
1130 | { <table.column> = <foreign_table.foreign_key> } |
1131 | ] |
1132 | |
1133 | JOIN |
1134 | <alias> <table> |
1135 | [JOIN ...] |
1136 | ON <table.column> = <foreign_table.foreign_key> |
1137 | |
1138 | An easy way to follow the examples below is to remember the following: |
1139 | |
1140 | Anything inside "[]" is a JOIN |
1141 | Anything inside "{}" is a condition for the enclosing JOIN |
1142 | |
1143 | The following examples utilize a "person" table in a family tree application. |
1144 | In order to express parent->child relationships, this table is self-joined: |
1145 | |
1146 | # Person->belongs_to('father' => 'Person'); |
1147 | # Person->belongs_to('mother' => 'Person'); |
1148 | |
1149 | C<from> can be used to nest joins. Here we return all children with a father, |
1150 | then search against all mothers of those children: |
1151 | |
1152 | $rs = $schema->resultset('Person')->search( |
5e8b1b2a |
1153 | undef, |
4a28c340 |
1154 | { |
1155 | alias => 'mother', # alias columns in accordance with "from" |
1156 | from => [ |
1157 | { mother => 'person' }, |
1158 | [ |
1159 | [ |
1160 | { child => 'person' }, |
1161 | [ |
1162 | { father => 'person' }, |
1163 | { 'father.person_id' => 'child.father_id' } |
1164 | ] |
1165 | ], |
1166 | { 'mother.person_id' => 'child.mother_id' } |
fd9f5466 |
1167 | ], |
4a28c340 |
1168 | ] |
1169 | }, |
1170 | ); |
1171 | |
1172 | # Equivalent SQL: |
1173 | # SELECT mother.* FROM person mother |
1174 | # JOIN ( |
1175 | # person child |
1176 | # JOIN person father |
1177 | # ON ( father.person_id = child.father_id ) |
1178 | # ) |
1179 | # ON ( mother.person_id = child.mother_id ) |
1180 | |
1181 | The type of any join can be controlled manually. To search against only people |
1182 | with a father in the person table, we could explicitly use C<INNER JOIN>: |
1183 | |
1184 | $rs = $schema->resultset('Person')->search( |
5e8b1b2a |
1185 | undef, |
4a28c340 |
1186 | { |
1187 | alias => 'child', # alias columns in accordance with "from" |
1188 | from => [ |
1189 | { child => 'person' }, |
1190 | [ |
1191 | { father => 'person', -join-type => 'inner' }, |
1192 | { 'father.id' => 'child.father_id' } |
1193 | ], |
1194 | ] |
1195 | }, |
1196 | ); |
1197 | |
1198 | # Equivalent SQL: |
1199 | # SELECT child.* FROM person child |
1200 | # INNER JOIN person father ON child.father_id = father.id |
ee38fa40 |
1201 | |
bfab575a |
1202 | =head2 page |
076652e8 |
1203 | |
a33df5d4 |
1204 | For a paged resultset, specifies which page to retrieve. Leave unset |
bfab575a |
1205 | for an unpaged resultset. |
076652e8 |
1206 | |
bfab575a |
1207 | =head2 rows |
076652e8 |
1208 | |
4a28c340 |
1209 | For a paged resultset, how many rows per page: |
1210 | |
1211 | rows => 10 |
1212 | |
1213 | Can also be used to simulate an SQL C<LIMIT>. |
076652e8 |
1214 | |
87c4e602 |
1215 | =head2 group_by |
1216 | |
1217 | =head3 Arguments: (arrayref) |
54540863 |
1218 | |
bda4c2b8 |
1219 | A arrayref of columns to group by. Can include columns of joined tables. |
54540863 |
1220 | |
675ce4a6 |
1221 | group_by => [qw/ column1 column2 ... /] |
1222 | |
54540863 |
1223 | =head2 distinct |
1224 | |
a33df5d4 |
1225 | Set to 1 to group by all columns. |
1226 | |
1227 | For more examples of using these attributes, see |
1228 | L<DBIx::Class::Manual::Cookbook>. |
54540863 |
1229 | |
bfab575a |
1230 | =cut |
076652e8 |
1231 | |
89c0a5a2 |
1232 | 1; |