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; |
bcd26419 |
11 | use Scalar::Util qw/weaken/; |
89c0a5a2 |
12 | |
701da8c4 |
13 | use base qw/DBIx::Class/; |
14 | __PACKAGE__->load_components(qw/AccessorGroup/); |
a50bcd52 |
15 | __PACKAGE__->mk_group_accessors('simple' => qw/result_source result_class/); |
701da8c4 |
16 | |
ee38fa40 |
17 | =head1 NAME |
18 | |
bfab575a |
19 | DBIx::Class::ResultSet - Responsible for fetching and creating resultset. |
ee38fa40 |
20 | |
bfab575a |
21 | =head1 SYNOPSIS |
ee38fa40 |
22 | |
a33df5d4 |
23 | my $rs = $schema->resultset('User')->search(registered => 1); |
24d67825 |
24 | my @rows = $schema->resultset('CD')->search(year => 2005); |
ee38fa40 |
25 | |
26 | =head1 DESCRIPTION |
27 | |
bfab575a |
28 | The resultset is also known as an iterator. It is responsible for handling |
a33df5d4 |
29 | queries that may return an arbitrary number of rows, e.g. via L</search> |
bfab575a |
30 | or a C<has_many> relationship. |
ee38fa40 |
31 | |
a33df5d4 |
32 | In the examples below, the following table classes are used: |
33 | |
34 | package MyApp::Schema::Artist; |
35 | use base qw/DBIx::Class/; |
f4409169 |
36 | __PACKAGE__->load_components(qw/Core/); |
a33df5d4 |
37 | __PACKAGE__->table('artist'); |
38 | __PACKAGE__->add_columns(qw/artistid name/); |
39 | __PACKAGE__->set_primary_key('artistid'); |
40 | __PACKAGE__->has_many(cds => 'MyApp::Schema::CD'); |
41 | 1; |
42 | |
43 | package MyApp::Schema::CD; |
44 | use base qw/DBIx::Class/; |
f4409169 |
45 | __PACKAGE__->load_components(qw/Core/); |
46 | __PACKAGE__->table('cd'); |
a33df5d4 |
47 | __PACKAGE__->add_columns(qw/cdid artist title year/); |
48 | __PACKAGE__->set_primary_key('cdid'); |
49 | __PACKAGE__->belongs_to(artist => 'MyApp::Schema::Artist'); |
50 | 1; |
51 | |
ee38fa40 |
52 | =head1 METHODS |
53 | |
87c4e602 |
54 | =head2 new |
55 | |
56 | =head3 Arguments: ($source, \%$attrs) |
ee38fa40 |
57 | |
a33df5d4 |
58 | The resultset constructor. Takes a source object (usually a |
181a28f4 |
59 | L<DBIx::Class::ResultSourceProxy::Table>) and an attribute hash (see L</ATTRIBUTES> |
a33df5d4 |
60 | below). Does not perform any queries -- these are executed as needed by the |
61 | other methods. |
62 | |
63 | Generally you won't need to construct a resultset manually. You'll |
64 | automatically get one from e.g. a L</search> called in scalar context: |
65 | |
66 | my $rs = $schema->resultset('CD')->search({ title => '100th Window' }); |
ee38fa40 |
67 | |
68 | =cut |
69 | |
89c0a5a2 |
70 | sub new { |
fea3d045 |
71 | my $class = shift; |
f9db5527 |
72 | return $class->new_result(@_) if ref $class; |
5e8b1b2a |
73 | |
fea3d045 |
74 | my ($source, $attrs) = @_; |
bcd26419 |
75 | weaken $source; |
ea20d0fd |
76 | $attrs = Storable::dclone($attrs || {}); # { %{ $attrs || {} } }; |
bcd26419 |
77 | #use Data::Dumper; warn Dumper($attrs); |
6aeb9185 |
78 | my $alias = ($attrs->{alias} ||= 'me'); |
5e8b1b2a |
79 | |
80 | $attrs->{columns} ||= delete $attrs->{cols} if $attrs->{cols}; |
1c258fc1 |
81 | delete $attrs->{as} if $attrs->{columns}; |
5e8b1b2a |
82 | $attrs->{columns} ||= [ $source->columns ] unless $attrs->{select}; |
1c258fc1 |
83 | $attrs->{select} = [ map { m/\./ ? $_ : "${alias}.$_" } @{delete $attrs->{columns}} ] |
84 | if $attrs->{columns}; |
5e8b1b2a |
85 | $attrs->{as} ||= [ map { m/^\Q$alias.\E(.+)$/ ? $1 : $_ } @{$attrs->{select}} ]; |
5ac6a044 |
86 | if (my $include = delete $attrs->{include_columns}) { |
87 | push(@{$attrs->{select}}, @$include); |
223aea40 |
88 | push(@{$attrs->{as}}, map { m/([^.]+)$/; $1; } @$include); |
5ac6a044 |
89 | } |
976f3686 |
90 | #use Data::Dumper; warn Dumper(@{$attrs}{qw/select as/}); |
5e8b1b2a |
91 | |
fea3d045 |
92 | $attrs->{from} ||= [ { $alias => $source->from } ]; |
8fab5eef |
93 | $attrs->{seen_join} ||= {}; |
5e8b1b2a |
94 | my %seen; |
b52e9bf8 |
95 | if (my $join = delete $attrs->{join}) { |
5e8b1b2a |
96 | foreach my $j (ref $join eq 'ARRAY' ? @$join : ($join)) { |
c7ce65e6 |
97 | if (ref $j eq 'HASH') { |
98 | $seen{$_} = 1 foreach keys %$j; |
99 | } else { |
100 | $seen{$j} = 1; |
101 | } |
102 | } |
8fab5eef |
103 | push(@{$attrs->{from}}, $source->resolve_join($join, $attrs->{alias}, $attrs->{seen_join})); |
c7ce65e6 |
104 | } |
5e8b1b2a |
105 | |
54540863 |
106 | $attrs->{group_by} ||= $attrs->{select} if delete $attrs->{distinct}; |
1c258fc1 |
107 | $attrs->{order_by} = [ $attrs->{order_by} ] if $attrs->{order_by} and !ref($attrs->{order_by}); |
a86b1efe |
108 | $attrs->{order_by} ||= []; |
109 | |
555af3d9 |
110 | my $collapse = $attrs->{collapse} || {}; |
b3e8ac9b |
111 | if (my $prefetch = delete $attrs->{prefetch}) { |
0f66a01b |
112 | my @pre_order; |
5e8b1b2a |
113 | foreach my $p (ref $prefetch eq 'ARRAY' ? @$prefetch : ($prefetch)) { |
114 | if ( ref $p eq 'HASH' ) { |
b3e8ac9b |
115 | foreach my $key (keys %$p) { |
116 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
117 | unless $seen{$key}; |
118 | } |
5e8b1b2a |
119 | } else { |
b3e8ac9b |
120 | push(@{$attrs->{from}}, $source->resolve_join($p, $attrs->{alias})) |
121 | unless $seen{$p}; |
122 | } |
a86b1efe |
123 | my @prefetch = $source->resolve_prefetch( |
0f66a01b |
124 | $p, $attrs->{alias}, {}, \@pre_order, $collapse); |
489709af |
125 | push(@{$attrs->{select}}, map { $_->[0] } @prefetch); |
126 | push(@{$attrs->{as}}, map { $_->[1] } @prefetch); |
b3e8ac9b |
127 | } |
0f66a01b |
128 | push(@{$attrs->{order_by}}, @pre_order); |
fef5d100 |
129 | } |
555af3d9 |
130 | $attrs->{collapse} = $collapse; |
5e8b1b2a |
131 | # use Data::Dumper; warn Dumper($collapse) if keys %{$collapse}; |
555af3d9 |
132 | |
6aeb9185 |
133 | if ($attrs->{page}) { |
134 | $attrs->{rows} ||= 10; |
135 | $attrs->{offset} ||= 0; |
136 | $attrs->{offset} += ($attrs->{rows} * ($attrs->{page} - 1)); |
137 | } |
0f66a01b |
138 | |
5e8b1b2a |
139 | bless { |
701da8c4 |
140 | result_source => $source, |
a50bcd52 |
141 | result_class => $attrs->{result_class} || $source->result_class, |
89c0a5a2 |
142 | cond => $attrs->{where}, |
0a3c5b43 |
143 | from => $attrs->{from}, |
0f66a01b |
144 | collapse => $collapse, |
3c5b25c5 |
145 | count => undef, |
93b004d3 |
146 | page => delete $attrs->{page}, |
3c5b25c5 |
147 | pager => undef, |
5e8b1b2a |
148 | attrs => $attrs |
149 | }, $class; |
89c0a5a2 |
150 | } |
151 | |
bfab575a |
152 | =head2 search |
0a3c5b43 |
153 | |
24d67825 |
154 | my @cds = $rs->search({ year => 2001 }); # "... WHERE year = 2001" |
155 | my $new_rs = $rs->search({ year => 2005 }); |
87f0da6a |
156 | |
6009260a |
157 | If you need to pass in additional attributes but no additional condition, |
5e8b1b2a |
158 | call it as C<search(undef, \%attrs);>. |
87f0da6a |
159 | |
24d67825 |
160 | # "SELECT name, artistid FROM $artist_table" |
161 | my @all_artists = $schema->resultset('Artist')->search(undef, { |
162 | columns => [qw/name artistid/], |
163 | }); |
0a3c5b43 |
164 | |
165 | =cut |
166 | |
167 | sub search { |
168 | my $self = shift; |
169 | |
ff7bb7a1 |
170 | my $rs; |
171 | if( @_ ) { |
172 | |
173 | my $attrs = { %{$self->{attrs}} }; |
8839560b |
174 | my $having = delete $attrs->{having}; |
223aea40 |
175 | $attrs = { %$attrs, %{ pop(@_) } } if @_ > 1 and ref $_[$#_] eq 'HASH'; |
6009260a |
176 | |
3e0e9e27 |
177 | my $where = (@_ |
178 | ? ((@_ == 1 || ref $_[0] eq "HASH") |
179 | ? shift |
180 | : ((@_ % 2) |
181 | ? $self->throw_exception( |
182 | "Odd number of arguments to search") |
183 | : {@_})) |
184 | : undef()); |
ff7bb7a1 |
185 | if (defined $where) { |
223aea40 |
186 | $attrs->{where} = (defined $attrs->{where} |
ad3d2d7c |
187 | ? { '-and' => |
188 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
189 | $where, $attrs->{where} ] } |
0a3c5b43 |
190 | : $where); |
ff7bb7a1 |
191 | } |
0a3c5b43 |
192 | |
8839560b |
193 | if (defined $having) { |
223aea40 |
194 | $attrs->{having} = (defined $attrs->{having} |
8839560b |
195 | ? { '-and' => |
196 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
197 | $having, $attrs->{having} ] } |
198 | : $having); |
8839560b |
199 | } |
200 | |
ff7bb7a1 |
201 | $rs = (ref $self)->new($self->result_source, $attrs); |
202 | } |
203 | else { |
204 | $rs = $self; |
223aea40 |
205 | $rs->reset; |
ff7bb7a1 |
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; |
5bd6785c |
257 | $self->throw_exception( "Unknown key $attrs->{key} on '" . $self->result_source->name . "'" ) |
87f0da6a |
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 | } |
223aea40 |
274 | foreach my $key (grep { ! m/\./ } keys %$query) { |
275 | $query->{"$self->{attrs}{alias}.$key"} = delete $query->{$key}; |
01bc091e |
276 | } |
716b3d29 |
277 | #warn Dumper($query); |
8389d433 |
278 | |
279 | if (keys %$attrs) { |
280 | my $rs = $self->search($query,$attrs); |
281 | return keys %{$rs->{collapse}} ? $rs->next : $rs->single; |
282 | } else { |
283 | return keys %{$self->{collapse}} ? $self->search($query)->next : $self->single($query); |
284 | } |
716b3d29 |
285 | } |
286 | |
b52e9bf8 |
287 | =head2 search_related |
288 | |
289 | $rs->search_related('relname', $cond?, $attrs?); |
290 | |
a33df5d4 |
291 | Search the specified relationship. Optionally specify a condition for matching |
292 | records. |
293 | |
b52e9bf8 |
294 | =cut |
295 | |
6aeb9185 |
296 | sub search_related { |
64acc2bc |
297 | return shift->related_resultset(shift)->search(@_); |
6aeb9185 |
298 | } |
b52e9bf8 |
299 | |
bfab575a |
300 | =head2 cursor |
ee38fa40 |
301 | |
bfab575a |
302 | Returns a storage-driven cursor to the given resultset. |
ee38fa40 |
303 | |
304 | =cut |
305 | |
73f58123 |
306 | sub cursor { |
307 | my ($self) = @_; |
223aea40 |
308 | my $attrs = { %{$self->{attrs}} }; |
73f58123 |
309 | return $self->{cursor} |
701da8c4 |
310 | ||= $self->result_source->storage->select($self->{from}, $attrs->{select}, |
73f58123 |
311 | $attrs->{where},$attrs); |
312 | } |
313 | |
a04ab285 |
314 | =head2 single |
315 | |
316 | Inflates the first result without creating a cursor |
317 | |
318 | =cut |
319 | |
320 | sub single { |
223aea40 |
321 | my ($self, $where) = @_; |
322 | my $attrs = { %{$self->{attrs}} }; |
323 | if ($where) { |
a04ab285 |
324 | if (defined $attrs->{where}) { |
325 | $attrs->{where} = { |
223aea40 |
326 | '-and' => |
327 | [ map { ref $_ eq 'ARRAY' ? [ -or => $_ ] : $_ } |
328 | $where, delete $attrs->{where} ] |
a04ab285 |
329 | }; |
330 | } else { |
223aea40 |
331 | $attrs->{where} = $where; |
a04ab285 |
332 | } |
333 | } |
334 | my @data = $self->result_source->storage->select_single( |
335 | $self->{from}, $attrs->{select}, |
336 | $attrs->{where},$attrs); |
337 | return (@data ? $self->_construct_object(@data) : ()); |
338 | } |
339 | |
340 | |
87f0da6a |
341 | =head2 search_like |
342 | |
a33df5d4 |
343 | Perform a search, but use C<LIKE> instead of equality as the condition. Note |
344 | that this is simply a convenience method; you most likely want to use |
345 | L</search> with specific operators. |
346 | |
347 | For more information, see L<DBIx::Class::Manual::Cookbook>. |
87f0da6a |
348 | |
349 | =cut |
58a4bd18 |
350 | |
351 | sub search_like { |
223aea40 |
352 | my $class = shift; |
353 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
354 | my $query = ref $_[0] eq 'HASH' ? { %{shift()} }: {@_}; |
58a4bd18 |
355 | $query->{$_} = { 'like' => $query->{$_} } for keys %$query; |
356 | return $class->search($query, { %$attrs }); |
357 | } |
358 | |
87c4e602 |
359 | =head2 slice |
360 | |
361 | =head3 Arguments: ($first, $last) |
ee38fa40 |
362 | |
bfab575a |
363 | Returns a subset of elements from the resultset. |
ee38fa40 |
364 | |
365 | =cut |
366 | |
89c0a5a2 |
367 | sub slice { |
368 | my ($self, $min, $max) = @_; |
369 | my $attrs = { %{ $self->{attrs} || {} } }; |
6aeb9185 |
370 | $attrs->{offset} ||= 0; |
371 | $attrs->{offset} += $min; |
89c0a5a2 |
372 | $attrs->{rows} = ($max ? ($max - $min + 1) : 1); |
701da8c4 |
373 | my $slice = (ref $self)->new($self->result_source, $attrs); |
89c0a5a2 |
374 | return (wantarray ? $slice->all : $slice); |
375 | } |
376 | |
87f0da6a |
377 | =head2 next |
ee38fa40 |
378 | |
a33df5d4 |
379 | Returns the next element in the resultset (C<undef> is there is none). |
380 | |
381 | Can be used to efficiently iterate over records in the resultset: |
382 | |
5e8b1b2a |
383 | my $rs = $schema->resultset('CD')->search; |
a33df5d4 |
384 | while (my $cd = $rs->next) { |
385 | print $cd->title; |
386 | } |
ee38fa40 |
387 | |
388 | =cut |
389 | |
89c0a5a2 |
390 | sub next { |
391 | my ($self) = @_; |
223aea40 |
392 | if (@{$self->{all_cache} || []}) { |
64acc2bc |
393 | $self->{all_cache_position} ||= 0; |
223aea40 |
394 | return $self->{all_cache}->[$self->{all_cache_position}++]; |
64acc2bc |
395 | } |
3e0e9e27 |
396 | if ($self->{attrs}{cache}) { |
0f66a01b |
397 | $self->{all_cache_position} = 1; |
3e0e9e27 |
398 | return ($self->all)[0]; |
399 | } |
0f66a01b |
400 | my @row = (exists $self->{stashed_row} |
401 | ? @{delete $self->{stashed_row}} |
402 | : $self->cursor->next); |
a953d8d9 |
403 | # warn Dumper(\@row); use Data::Dumper; |
89c0a5a2 |
404 | return unless (@row); |
c7ce65e6 |
405 | return $self->_construct_object(@row); |
406 | } |
407 | |
408 | sub _construct_object { |
409 | my ($self, @row) = @_; |
b3e8ac9b |
410 | my @as = @{ $self->{attrs}{as} }; |
223aea40 |
411 | |
0f66a01b |
412 | my $info = $self->_collapse_result(\@as, \@row); |
223aea40 |
413 | |
a50bcd52 |
414 | my $new = $self->result_class->inflate_result($self->result_source, @$info); |
223aea40 |
415 | |
33ce49d6 |
416 | $new = $self->{attrs}{record_filter}->($new) |
417 | if exists $self->{attrs}{record_filter}; |
418 | return $new; |
89c0a5a2 |
419 | } |
420 | |
0f66a01b |
421 | sub _collapse_result { |
422 | my ($self, $as, $row, $prefix) = @_; |
423 | |
424 | my %const; |
425 | |
426 | my @copy = @$row; |
5a5bec6c |
427 | foreach my $this_as (@$as) { |
428 | my $val = shift @copy; |
429 | if (defined $prefix) { |
430 | if ($this_as =~ m/^\Q${prefix}.\E(.+)$/) { |
431 | my $remain = $1; |
223aea40 |
432 | $remain =~ /^(?:(.*)\.)?([^.]+)$/; |
5a5bec6c |
433 | $const{$1||''}{$2} = $val; |
434 | } |
435 | } else { |
223aea40 |
436 | $this_as =~ /^(?:(.*)\.)?([^.]+)$/; |
5a5bec6c |
437 | $const{$1||''}{$2} = $val; |
0f66a01b |
438 | } |
0f66a01b |
439 | } |
440 | |
0f66a01b |
441 | my $info = [ {}, {} ]; |
442 | foreach my $key (keys %const) { |
443 | if (length $key) { |
444 | my $target = $info; |
445 | my @parts = split(/\./, $key); |
446 | foreach my $p (@parts) { |
447 | $target = $target->[1]->{$p} ||= []; |
448 | } |
449 | $target->[0] = $const{$key}; |
450 | } else { |
451 | $info->[0] = $const{$key}; |
452 | } |
453 | } |
454 | |
5a5bec6c |
455 | my @collapse = (defined($prefix) |
456 | ? (map { (m/^\Q${prefix}.\E(.+)$/ ? ($1) : ()); } |
457 | keys %{$self->{collapse}}) |
458 | : keys %{$self->{collapse}}); |
459 | if (@collapse) { |
460 | my ($c) = sort { length $a <=> length $b } @collapse; |
0f66a01b |
461 | my $target = $info; |
0f66a01b |
462 | foreach my $p (split(/\./, $c)) { |
5a5bec6c |
463 | $target = $target->[1]->{$p} ||= []; |
0f66a01b |
464 | } |
5a5bec6c |
465 | my $c_prefix = (defined($prefix) ? "${prefix}.${c}" : $c); |
466 | my @co_key = @{$self->{collapse}{$c_prefix}}; |
0f66a01b |
467 | my %co_check = map { ($_, $target->[0]->{$_}); } @co_key; |
5a5bec6c |
468 | my $tree = $self->_collapse_result($as, $row, $c_prefix); |
0f66a01b |
469 | my (@final, @raw); |
5a5bec6c |
470 | while ( !(grep { |
471 | !defined($tree->[0]->{$_}) |
472 | || $co_check{$_} ne $tree->[0]->{$_} |
473 | } @co_key) ) { |
0f66a01b |
474 | push(@final, $tree); |
475 | last unless (@raw = $self->cursor->next); |
476 | $row = $self->{stashed_row} = \@raw; |
5a5bec6c |
477 | $tree = $self->_collapse_result($as, $row, $c_prefix); |
478 | #warn Data::Dumper::Dumper($tree, $row); |
0f66a01b |
479 | } |
223aea40 |
480 | @$target = @final; |
0f66a01b |
481 | } |
482 | |
0f66a01b |
483 | return $info; |
484 | } |
485 | |
87c4e602 |
486 | =head2 result_source |
701da8c4 |
487 | |
488 | Returns a reference to the result source for this recordset. |
489 | |
490 | =cut |
491 | |
492 | |
bfab575a |
493 | =head2 count |
ee38fa40 |
494 | |
bfab575a |
495 | Performs an SQL C<COUNT> with the same query as the resultset was built |
6009260a |
496 | with to find the number of elements. If passed arguments, does a search |
497 | on the resultset and counts the results of that. |
ee38fa40 |
498 | |
bda4c2b8 |
499 | Note: When using C<count> with C<group_by>, L<DBIX::Class> emulates C<GROUP BY> |
500 | using C<COUNT( DISTINCT( columns ) )>. Some databases (notably SQLite) do |
501 | not support C<DISTINCT> with multiple columns. If you are using such a |
502 | database, you should only use columns from the main table in your C<group_by> |
503 | clause. |
504 | |
ee38fa40 |
505 | =cut |
506 | |
89c0a5a2 |
507 | sub count { |
6009260a |
508 | my $self = shift; |
223aea40 |
509 | return $self->search(@_)->count if @_ and defined $_[0]; |
84e3c114 |
510 | return scalar @{ $self->get_cache } if @{ $self->get_cache }; |
15c382be |
511 | |
84e3c114 |
512 | my $count = $self->_count; |
513 | return 0 unless $count; |
15c382be |
514 | |
6aeb9185 |
515 | $count -= $self->{attrs}{offset} if $self->{attrs}{offset}; |
516 | $count = $self->{attrs}{rows} if |
223aea40 |
517 | $self->{attrs}{rows} and $self->{attrs}{rows} < $count; |
6aeb9185 |
518 | return $count; |
89c0a5a2 |
519 | } |
520 | |
84e3c114 |
521 | sub _count { # Separated out so pager can get the full count |
522 | my $self = shift; |
523 | my $select = { count => '*' }; |
524 | my $attrs = { %{ $self->{attrs} } }; |
525 | if (my $group_by = delete $attrs->{group_by}) { |
526 | delete $attrs->{having}; |
527 | my @distinct = (ref $group_by ? @$group_by : ($group_by)); |
528 | # todo: try CONCAT for multi-column pk |
529 | my @pk = $self->result_source->primary_columns; |
530 | if (@pk == 1) { |
531 | foreach my $column (@distinct) { |
532 | if ($column =~ qr/^(?:\Q$attrs->{alias}.\E)?$pk[0]$/) { |
533 | @distinct = ($column); |
534 | last; |
535 | } |
536 | } |
537 | } |
538 | |
539 | $select = { count => { distinct => \@distinct } }; |
540 | #use Data::Dumper; die Dumper $select; |
541 | } |
542 | |
543 | $attrs->{select} = $select; |
544 | $attrs->{as} = [qw/count/]; |
545 | |
546 | # offset, order by and page are not needed to count. record_filter is cdbi |
547 | delete $attrs->{$_} for qw/rows offset order_by page pager record_filter/; |
548 | |
549 | my ($count) = (ref $self)->new($self->result_source, $attrs)->cursor->next; |
550 | return $count; |
551 | } |
552 | |
bfab575a |
553 | =head2 count_literal |
6009260a |
554 | |
a33df5d4 |
555 | Calls L</search_literal> with the passed arguments, then L</count>. |
6009260a |
556 | |
557 | =cut |
558 | |
559 | sub count_literal { shift->search_literal(@_)->count; } |
560 | |
bfab575a |
561 | =head2 all |
ee38fa40 |
562 | |
bfab575a |
563 | Returns all elements in the resultset. Called implictly if the resultset |
564 | is returned in list context. |
ee38fa40 |
565 | |
566 | =cut |
567 | |
89c0a5a2 |
568 | sub all { |
569 | my ($self) = @_; |
223aea40 |
570 | return @{ $self->get_cache } if @{ $self->get_cache }; |
5a5bec6c |
571 | |
572 | my @obj; |
573 | |
574 | if (keys %{$self->{collapse}}) { |
575 | # Using $self->cursor->all is really just an optimisation. |
576 | # If we're collapsing has_many prefetches it probably makes |
577 | # very little difference, and this is cleaner than hacking |
578 | # _construct_object to survive the approach |
5a5bec6c |
579 | $self->cursor->reset; |
479ed423 |
580 | my @row = $self->cursor->next; |
581 | while (@row) { |
5a5bec6c |
582 | push(@obj, $self->_construct_object(@row)); |
479ed423 |
583 | @row = (exists $self->{stashed_row} |
584 | ? @{delete $self->{stashed_row}} |
585 | : $self->cursor->next); |
5a5bec6c |
586 | } |
587 | } else { |
223aea40 |
588 | @obj = map { $self->_construct_object(@$_) } $self->cursor->all; |
64acc2bc |
589 | } |
5a5bec6c |
590 | |
223aea40 |
591 | $self->set_cache(\@obj) if $self->{attrs}{cache}; |
5a5bec6c |
592 | return @obj; |
89c0a5a2 |
593 | } |
594 | |
bfab575a |
595 | =head2 reset |
ee38fa40 |
596 | |
bfab575a |
597 | Resets the resultset's cursor, so you can iterate through the elements again. |
ee38fa40 |
598 | |
599 | =cut |
600 | |
89c0a5a2 |
601 | sub reset { |
602 | my ($self) = @_; |
64acc2bc |
603 | $self->{all_cache_position} = 0; |
73f58123 |
604 | $self->cursor->reset; |
89c0a5a2 |
605 | return $self; |
606 | } |
607 | |
bfab575a |
608 | =head2 first |
ee38fa40 |
609 | |
bfab575a |
610 | Resets the resultset and returns the first element. |
ee38fa40 |
611 | |
612 | =cut |
613 | |
89c0a5a2 |
614 | sub first { |
615 | return $_[0]->reset->next; |
616 | } |
617 | |
87c4e602 |
618 | =head2 update |
619 | |
620 | =head3 Arguments: (\%values) |
c01ab172 |
621 | |
a33df5d4 |
622 | Sets the specified columns in the resultset to the supplied values. |
c01ab172 |
623 | |
624 | =cut |
625 | |
626 | sub update { |
627 | my ($self, $values) = @_; |
701da8c4 |
628 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
629 | return $self->result_source->storage->update( |
630 | $self->result_source->from, $values, $self->{cond}); |
c01ab172 |
631 | } |
632 | |
87c4e602 |
633 | =head2 update_all |
634 | |
635 | =head3 Arguments: (\%values) |
c01ab172 |
636 | |
a33df5d4 |
637 | Fetches all objects and updates them one at a time. Note that C<update_all> |
638 | will run cascade triggers while L</update> will not. |
c01ab172 |
639 | |
640 | =cut |
641 | |
642 | sub update_all { |
643 | my ($self, $values) = @_; |
701da8c4 |
644 | $self->throw_exception("Values for update must be a hash") unless ref $values eq 'HASH'; |
c01ab172 |
645 | foreach my $obj ($self->all) { |
646 | $obj->set_columns($values)->update; |
647 | } |
648 | return 1; |
649 | } |
650 | |
bfab575a |
651 | =head2 delete |
ee38fa40 |
652 | |
c01ab172 |
653 | Deletes the contents of the resultset from its result source. |
ee38fa40 |
654 | |
655 | =cut |
656 | |
28927b50 |
657 | sub delete { |
89c0a5a2 |
658 | my ($self) = @_; |
ca4b5ab7 |
659 | my $del = {}; |
7ed3d6dc |
660 | |
661 | if (!ref($self->{cond})) { |
662 | |
663 | # No-op. No condition, we're deleting everything |
664 | |
665 | } elsif (ref $self->{cond} eq 'ARRAY') { |
666 | |
ca4b5ab7 |
667 | $del = [ map { my %hash; |
668 | foreach my $key (keys %{$_}) { |
223aea40 |
669 | $key =~ /([^.]+)$/; |
ca4b5ab7 |
670 | $hash{$1} = $_->{$key}; |
671 | }; \%hash; } @{$self->{cond}} ]; |
7ed3d6dc |
672 | |
673 | } elsif (ref $self->{cond} eq 'HASH') { |
674 | |
675 | if ((keys %{$self->{cond}})[0] eq '-and') { |
676 | |
677 | $del->{-and} = [ map { my %hash; |
678 | foreach my $key (keys %{$_}) { |
679 | $key =~ /([^.]+)$/; |
680 | $hash{$1} = $_->{$key}; |
681 | }; \%hash; } @{$self->{cond}{-and}} ]; |
682 | |
683 | } else { |
684 | |
685 | foreach my $key (keys %{$self->{cond}}) { |
223aea40 |
686 | $key =~ /([^.]+)$/; |
7ed3d6dc |
687 | $del->{$1} = $self->{cond}{$key}; |
688 | } |
ca4b5ab7 |
689 | } |
7ed3d6dc |
690 | } else { |
691 | $self->throw_exception( |
692 | "Can't delete on resultset with condition unless hash or array"); |
ca4b5ab7 |
693 | } |
7ed3d6dc |
694 | |
ca4b5ab7 |
695 | $self->result_source->storage->delete($self->result_source->from, $del); |
89c0a5a2 |
696 | return 1; |
697 | } |
698 | |
c01ab172 |
699 | =head2 delete_all |
700 | |
a33df5d4 |
701 | Fetches all objects and deletes them one at a time. Note that C<delete_all> |
702 | will run cascade triggers while L</delete> will not. |
c01ab172 |
703 | |
704 | =cut |
705 | |
706 | sub delete_all { |
707 | my ($self) = @_; |
708 | $_->delete for $self->all; |
709 | return 1; |
710 | } |
28927b50 |
711 | |
bfab575a |
712 | =head2 pager |
ee38fa40 |
713 | |
714 | Returns a L<Data::Page> object for the current resultset. Only makes |
a33df5d4 |
715 | sense for queries with a C<page> attribute. |
ee38fa40 |
716 | |
717 | =cut |
718 | |
3c5b25c5 |
719 | sub pager { |
720 | my ($self) = @_; |
721 | my $attrs = $self->{attrs}; |
701da8c4 |
722 | $self->throw_exception("Can't create pager for non-paged rs") unless $self->{page}; |
6aeb9185 |
723 | $attrs->{rows} ||= 10; |
6aeb9185 |
724 | return $self->{pager} ||= Data::Page->new( |
84e3c114 |
725 | $self->_count, $attrs->{rows}, $self->{page}); |
3c5b25c5 |
726 | } |
727 | |
87c4e602 |
728 | =head2 page |
729 | |
730 | =head3 Arguments: ($page_num) |
ee38fa40 |
731 | |
bfab575a |
732 | Returns a new resultset for the specified page. |
ee38fa40 |
733 | |
734 | =cut |
735 | |
3c5b25c5 |
736 | sub page { |
737 | my ($self, $page) = @_; |
6aeb9185 |
738 | my $attrs = { %{$self->{attrs}} }; |
3c5b25c5 |
739 | $attrs->{page} = $page; |
701da8c4 |
740 | return (ref $self)->new($self->result_source, $attrs); |
fea3d045 |
741 | } |
742 | |
87c4e602 |
743 | =head2 new_result |
744 | |
745 | =head3 Arguments: (\%vals) |
fea3d045 |
746 | |
87f0da6a |
747 | Creates a result in the resultset's result class. |
fea3d045 |
748 | |
749 | =cut |
750 | |
751 | sub new_result { |
752 | my ($self, $values) = @_; |
701da8c4 |
753 | $self->throw_exception( "new_result needs a hash" ) |
fea3d045 |
754 | unless (ref $values eq 'HASH'); |
701da8c4 |
755 | $self->throw_exception( "Can't abstract implicit construct, condition not a hash" ) |
fea3d045 |
756 | if ($self->{cond} && !(ref $self->{cond} eq 'HASH')); |
757 | my %new = %$values; |
758 | my $alias = $self->{attrs}{alias}; |
759 | foreach my $key (keys %{$self->{cond}||{}}) { |
223aea40 |
760 | $new{$1} = $self->{cond}{$key} if ($key =~ m/^(?:\Q${alias}.\E)?([^.]+)$/); |
fea3d045 |
761 | } |
a50bcd52 |
762 | my $obj = $self->result_class->new(\%new); |
701da8c4 |
763 | $obj->result_source($self->result_source) if $obj->can('result_source'); |
223aea40 |
764 | return $obj; |
fea3d045 |
765 | } |
766 | |
87c4e602 |
767 | =head2 create |
768 | |
769 | =head3 Arguments: (\%vals) |
fea3d045 |
770 | |
87f0da6a |
771 | Inserts a record into the resultset and returns the object. |
fea3d045 |
772 | |
a33df5d4 |
773 | Effectively a shortcut for C<< ->new_result(\%vals)->insert >>. |
fea3d045 |
774 | |
775 | =cut |
776 | |
777 | sub create { |
778 | my ($self, $attrs) = @_; |
701da8c4 |
779 | $self->throw_exception( "create needs a hashref" ) unless ref $attrs eq 'HASH'; |
fea3d045 |
780 | return $self->new_result($attrs)->insert; |
3c5b25c5 |
781 | } |
782 | |
87c4e602 |
783 | =head2 find_or_create |
784 | |
785 | =head3 Arguments: (\%vals, \%attrs?) |
87f0da6a |
786 | |
787 | $class->find_or_create({ key => $val, ... }); |
c2b15ecc |
788 | |
fd9f5466 |
789 | Searches for a record matching the search condition; if it doesn't find one, |
790 | creates one and returns that instead. |
87f0da6a |
791 | |
87f0da6a |
792 | my $cd = $schema->resultset('CD')->find_or_create({ |
793 | cdid => 5, |
794 | artist => 'Massive Attack', |
795 | title => 'Mezzanine', |
796 | year => 2005, |
797 | }); |
798 | |
799 | Also takes an optional C<key> attribute, to search by a specific key or unique |
800 | constraint. For example: |
801 | |
802 | my $cd = $schema->resultset('CD')->find_or_create( |
803 | { |
804 | artist => 'Massive Attack', |
805 | title => 'Mezzanine', |
806 | }, |
807 | { key => 'artist_title' } |
808 | ); |
809 | |
810 | See also L</find> and L</update_or_create>. |
811 | |
c2b15ecc |
812 | =cut |
813 | |
814 | sub find_or_create { |
815 | my $self = shift; |
87f0da6a |
816 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
223aea40 |
817 | my $hash = ref $_[0] eq 'HASH' ? shift : {@_}; |
87f0da6a |
818 | my $exists = $self->find($hash, $attrs); |
223aea40 |
819 | return defined $exists ? $exists : $self->create($hash); |
c2b15ecc |
820 | } |
821 | |
87f0da6a |
822 | =head2 update_or_create |
823 | |
824 | $class->update_or_create({ key => $val, ... }); |
825 | |
826 | First, search for an existing row matching one of the unique constraints |
827 | (including the primary key) on the source of this resultset. If a row is |
828 | found, update it with the other given column values. Otherwise, create a new |
829 | row. |
830 | |
831 | Takes an optional C<key> attribute to search on a specific unique constraint. |
832 | For example: |
833 | |
834 | # In your application |
835 | my $cd = $schema->resultset('CD')->update_or_create( |
836 | { |
837 | artist => 'Massive Attack', |
838 | title => 'Mezzanine', |
839 | year => 1998, |
840 | }, |
841 | { key => 'artist_title' } |
842 | ); |
843 | |
844 | If no C<key> is specified, it searches on all unique constraints defined on the |
845 | source, including the primary key. |
846 | |
847 | If the C<key> is specified as C<primary>, search only on the primary key. |
848 | |
a33df5d4 |
849 | See also L</find> and L</find_or_create>. |
850 | |
87f0da6a |
851 | =cut |
852 | |
853 | sub update_or_create { |
854 | my $self = shift; |
87f0da6a |
855 | my $attrs = (@_ > 1 && ref $_[$#_] eq 'HASH' ? pop(@_) : {}); |
223aea40 |
856 | my $hash = ref $_[0] eq 'HASH' ? shift : {@_}; |
87f0da6a |
857 | |
701da8c4 |
858 | my %unique_constraints = $self->result_source->unique_constraints; |
87f0da6a |
859 | my @constraint_names = (exists $attrs->{key} |
860 | ? ($attrs->{key}) |
861 | : keys %unique_constraints); |
862 | |
863 | my @unique_hashes; |
864 | foreach my $name (@constraint_names) { |
865 | my @unique_cols = @{ $unique_constraints{$name} }; |
866 | my %unique_hash = |
867 | map { $_ => $hash->{$_} } |
868 | grep { exists $hash->{$_} } |
869 | @unique_cols; |
870 | |
871 | push @unique_hashes, \%unique_hash |
872 | if (scalar keys %unique_hash == scalar @unique_cols); |
873 | } |
874 | |
87f0da6a |
875 | if (@unique_hashes) { |
223aea40 |
876 | my $row = $self->single(\@unique_hashes); |
877 | if (defined $row) { |
87f0da6a |
878 | $row->set_columns($hash); |
879 | $row->update; |
223aea40 |
880 | return $row; |
87f0da6a |
881 | } |
882 | } |
883 | |
223aea40 |
884 | return $self->create($hash); |
87f0da6a |
885 | } |
886 | |
64acc2bc |
887 | =head2 get_cache |
888 | |
889 | Gets the contents of the cache for the resultset. |
890 | |
891 | =cut |
892 | |
893 | sub get_cache { |
223aea40 |
894 | shift->{all_cache} || []; |
64acc2bc |
895 | } |
896 | |
897 | =head2 set_cache |
898 | |
899 | Sets the contents of the cache for the resultset. Expects an arrayref of objects of the same class as those produced by the resultset. |
900 | |
901 | =cut |
902 | |
903 | sub set_cache { |
904 | my ( $self, $data ) = @_; |
905 | $self->throw_exception("set_cache requires an arrayref") |
906 | if ref $data ne 'ARRAY'; |
a50bcd52 |
907 | my $result_class = $self->result_class; |
64acc2bc |
908 | foreach( @$data ) { |
909 | $self->throw_exception("cannot cache object of type '$_', expected '$result_class'") |
910 | if ref $_ ne $result_class; |
911 | } |
912 | $self->{all_cache} = $data; |
913 | } |
914 | |
915 | =head2 clear_cache |
916 | |
917 | Clears the cache for the resultset. |
918 | |
919 | =cut |
920 | |
921 | sub clear_cache { |
223aea40 |
922 | shift->set_cache([]); |
64acc2bc |
923 | } |
924 | |
925 | =head2 related_resultset |
926 | |
927 | Returns a related resultset for the supplied relationship name. |
928 | |
24d67825 |
929 | $artist_rs = $schema->resultset('CD')->related_resultset('Artist'); |
64acc2bc |
930 | |
931 | =cut |
932 | |
933 | sub related_resultset { |
934 | my ( $self, $rel, @rest ) = @_; |
935 | $self->{related_resultsets} ||= {}; |
223aea40 |
936 | return $self->{related_resultsets}{$rel} ||= do { |
937 | #warn "fetching related resultset for rel '$rel'"; |
938 | my $rel_obj = $self->result_source->relationship_info($rel); |
939 | $self->throw_exception( |
940 | "search_related: result source '" . $self->result_source->name . |
941 | "' has no such relationship ${rel}") |
942 | unless $rel_obj; #die Dumper $self->{attrs}; |
943 | |
944 | my $rs = $self->search(undef, { join => $rel }); |
945 | my $alias = defined $rs->{attrs}{seen_join}{$rel} |
946 | && $rs->{attrs}{seen_join}{$rel} > 1 |
947 | ? join('_', $rel, $rs->{attrs}{seen_join}{$rel}) |
948 | : $rel; |
949 | |
64acc2bc |
950 | $self->result_source->schema->resultset($rel_obj->{class} |
951 | )->search( undef, |
952 | { %{$rs->{attrs}}, |
953 | alias => $alias, |
223aea40 |
954 | select => undef, |
955 | as => undef } |
956 | )->search(@rest); |
957 | }; |
64acc2bc |
958 | } |
959 | |
701da8c4 |
960 | =head2 throw_exception |
961 | |
962 | See Schema's throw_exception |
963 | |
964 | =cut |
965 | |
966 | sub throw_exception { |
967 | my $self=shift; |
968 | $self->result_source->schema->throw_exception(@_); |
969 | } |
970 | |
40dbc108 |
971 | =head1 ATTRIBUTES |
076652e8 |
972 | |
a33df5d4 |
973 | The resultset takes various attributes that modify its behavior. Here's an |
974 | overview of them: |
bfab575a |
975 | |
976 | =head2 order_by |
076652e8 |
977 | |
24d67825 |
978 | Which column(s) to order the results by. This is currently passed |
979 | through directly to SQL, so you can give e.g. C<year DESC> for a |
980 | descending order on the column `year'. |
076652e8 |
981 | |
5e8b1b2a |
982 | =head2 columns |
87c4e602 |
983 | |
984 | =head3 Arguments: (arrayref) |
976f3686 |
985 | |
a33df5d4 |
986 | Shortcut to request a particular set of columns to be retrieved. Adds |
987 | C<me.> onto the start of any column without a C<.> in it and sets C<select> |
5e8b1b2a |
988 | from that, then auto-populates C<as> from C<select> as normal. (You may also |
989 | use the C<cols> attribute, as in earlier versions of DBIC.) |
976f3686 |
990 | |
87c4e602 |
991 | =head2 include_columns |
992 | |
993 | =head3 Arguments: (arrayref) |
5ac6a044 |
994 | |
995 | Shortcut to include additional columns in the returned results - for example |
996 | |
24d67825 |
997 | $schema->resultset('CD')->search(undef, { |
998 | include_columns => ['artist.name'], |
999 | join => ['artist'] |
1000 | }); |
5ac6a044 |
1001 | |
24d67825 |
1002 | would return all CDs and include a 'name' column to the information |
1003 | passed to object inflation |
5ac6a044 |
1004 | |
87c4e602 |
1005 | =head2 select |
1006 | |
1007 | =head3 Arguments: (arrayref) |
976f3686 |
1008 | |
4a28c340 |
1009 | Indicates which columns should be selected from the storage. You can use |
1010 | column names, or in the case of RDBMS back ends, function or stored procedure |
1011 | names: |
1012 | |
24d67825 |
1013 | $rs = $schema->resultset('Employee')->search(undef, { |
1014 | select => [ |
1015 | 'name', |
1016 | { count => 'employeeid' }, |
1017 | { sum => 'salary' } |
1018 | ] |
1019 | }); |
4a28c340 |
1020 | |
1021 | When you use function/stored procedure names and do not supply an C<as> |
1022 | attribute, the column names returned are storage-dependent. E.g. MySQL would |
24d67825 |
1023 | return a column named C<count(employeeid)> in the above example. |
976f3686 |
1024 | |
87c4e602 |
1025 | =head2 as |
1026 | |
1027 | =head3 Arguments: (arrayref) |
076652e8 |
1028 | |
4a28c340 |
1029 | Indicates column names for object inflation. This is used in conjunction with |
1030 | C<select>, usually when C<select> contains one or more function or stored |
1031 | procedure names: |
1032 | |
24d67825 |
1033 | $rs = $schema->resultset('Employee')->search(undef, { |
1034 | select => [ |
1035 | 'name', |
1036 | { count => 'employeeid' } |
1037 | ], |
a0638a7b |
1038 | as => ['name', 'employee_count'], |
24d67825 |
1039 | }); |
4a28c340 |
1040 | |
24d67825 |
1041 | my $employee = $rs->first(); # get the first Employee |
4a28c340 |
1042 | |
1043 | If the object against which the search is performed already has an accessor |
1044 | matching a column name specified in C<as>, the value can be retrieved using |
1045 | the accessor as normal: |
1046 | |
24d67825 |
1047 | my $name = $employee->name(); |
4a28c340 |
1048 | |
1049 | If on the other hand an accessor does not exist in the object, you need to |
1050 | use C<get_column> instead: |
1051 | |
24d67825 |
1052 | my $employee_count = $employee->get_column('employee_count'); |
4a28c340 |
1053 | |
1054 | You can create your own accessors if required - see |
1055 | L<DBIx::Class::Manual::Cookbook> for details. |
ee38fa40 |
1056 | |
bfab575a |
1057 | =head2 join |
ee38fa40 |
1058 | |
a33df5d4 |
1059 | Contains a list of relationships that should be joined for this query. For |
1060 | example: |
1061 | |
1062 | # Get CDs by Nine Inch Nails |
1063 | my $rs = $schema->resultset('CD')->search( |
1064 | { 'artist.name' => 'Nine Inch Nails' }, |
1065 | { join => 'artist' } |
1066 | ); |
1067 | |
1068 | Can also contain a hash reference to refer to the other relation's relations. |
1069 | For example: |
1070 | |
1071 | package MyApp::Schema::Track; |
1072 | use base qw/DBIx::Class/; |
1073 | __PACKAGE__->table('track'); |
1074 | __PACKAGE__->add_columns(qw/trackid cd position title/); |
1075 | __PACKAGE__->set_primary_key('trackid'); |
1076 | __PACKAGE__->belongs_to(cd => 'MyApp::Schema::CD'); |
1077 | 1; |
1078 | |
1079 | # In your application |
1080 | my $rs = $schema->resultset('Artist')->search( |
1081 | { 'track.title' => 'Teardrop' }, |
1082 | { |
1083 | join => { cd => 'track' }, |
1084 | order_by => 'artist.name', |
1085 | } |
1086 | ); |
1087 | |
2cb360cc |
1088 | If the same join is supplied twice, it will be aliased to <rel>_2 (and |
1089 | similarly for a third time). For e.g. |
1090 | |
24d67825 |
1091 | my $rs = $schema->resultset('Artist')->search({ |
1092 | 'cds.title' => 'Down to Earth', |
1093 | 'cds_2.title' => 'Popular', |
1094 | }, { |
1095 | join => [ qw/cds cds/ ], |
1096 | }); |
2cb360cc |
1097 | |
24d67825 |
1098 | will return a set of all artists that have both a cd with title 'Down |
1099 | to Earth' and a cd with title 'Popular'. |
2cb360cc |
1100 | |
1101 | If you want to fetch related objects from other tables as well, see C<prefetch> |
ae1c90a1 |
1102 | below. |
ee38fa40 |
1103 | |
87c4e602 |
1104 | =head2 prefetch |
1105 | |
1106 | =head3 Arguments: arrayref/hashref |
ee38fa40 |
1107 | |
ae1c90a1 |
1108 | Contains one or more relationships that should be fetched along with the main |
bfab575a |
1109 | query (when they are accessed afterwards they will have already been |
a33df5d4 |
1110 | "prefetched"). This is useful for when you know you will need the related |
ae1c90a1 |
1111 | objects, because it saves at least one query: |
1112 | |
1113 | my $rs = $schema->resultset('Tag')->search( |
5e8b1b2a |
1114 | undef, |
ae1c90a1 |
1115 | { |
1116 | prefetch => { |
1117 | cd => 'artist' |
1118 | } |
1119 | } |
1120 | ); |
1121 | |
1122 | The initial search results in SQL like the following: |
1123 | |
1124 | SELECT tag.*, cd.*, artist.* FROM tag |
1125 | JOIN cd ON tag.cd = cd.cdid |
1126 | JOIN artist ON cd.artist = artist.artistid |
1127 | |
1128 | L<DBIx::Class> has no need to go back to the database when we access the |
1129 | C<cd> or C<artist> relationships, which saves us two SQL statements in this |
1130 | case. |
1131 | |
2cb360cc |
1132 | Simple prefetches will be joined automatically, so there is no need |
1133 | for a C<join> attribute in the above search. If you're prefetching to |
1134 | depth (e.g. { cd => { artist => 'label' } or similar), you'll need to |
1135 | specify the join as well. |
ae1c90a1 |
1136 | |
1137 | C<prefetch> can be used with the following relationship types: C<belongs_to>, |
2cb360cc |
1138 | C<has_one> (or if you're using C<add_relationship>, any relationship declared |
1139 | with an accessor type of 'single' or 'filter'). |
ee38fa40 |
1140 | |
87c4e602 |
1141 | =head2 from |
1142 | |
1143 | =head3 Arguments: (arrayref) |
ee38fa40 |
1144 | |
4a28c340 |
1145 | The C<from> attribute gives you manual control over the C<FROM> clause of SQL |
1146 | statements generated by L<DBIx::Class>, allowing you to express custom C<JOIN> |
1147 | clauses. |
ee38fa40 |
1148 | |
a33df5d4 |
1149 | NOTE: Use this on your own risk. This allows you to shoot off your foot! |
4a28c340 |
1150 | C<join> will usually do what you need and it is strongly recommended that you |
1151 | avoid using C<from> unless you cannot achieve the desired result using C<join>. |
1152 | |
1153 | In simple terms, C<from> works as follows: |
1154 | |
1155 | [ |
1156 | { <alias> => <table>, -join-type => 'inner|left|right' } |
1157 | [] # nested JOIN (optional) |
1158 | { <table.column> = <foreign_table.foreign_key> } |
1159 | ] |
1160 | |
1161 | JOIN |
1162 | <alias> <table> |
1163 | [JOIN ...] |
1164 | ON <table.column> = <foreign_table.foreign_key> |
1165 | |
1166 | An easy way to follow the examples below is to remember the following: |
1167 | |
1168 | Anything inside "[]" is a JOIN |
1169 | Anything inside "{}" is a condition for the enclosing JOIN |
1170 | |
1171 | The following examples utilize a "person" table in a family tree application. |
1172 | In order to express parent->child relationships, this table is self-joined: |
1173 | |
1174 | # Person->belongs_to('father' => 'Person'); |
1175 | # Person->belongs_to('mother' => 'Person'); |
1176 | |
1177 | C<from> can be used to nest joins. Here we return all children with a father, |
1178 | then search against all mothers of those children: |
1179 | |
1180 | $rs = $schema->resultset('Person')->search( |
5e8b1b2a |
1181 | undef, |
4a28c340 |
1182 | { |
1183 | alias => 'mother', # alias columns in accordance with "from" |
1184 | from => [ |
1185 | { mother => 'person' }, |
1186 | [ |
1187 | [ |
1188 | { child => 'person' }, |
1189 | [ |
1190 | { father => 'person' }, |
1191 | { 'father.person_id' => 'child.father_id' } |
1192 | ] |
1193 | ], |
1194 | { 'mother.person_id' => 'child.mother_id' } |
fd9f5466 |
1195 | ], |
4a28c340 |
1196 | ] |
1197 | }, |
1198 | ); |
1199 | |
1200 | # Equivalent SQL: |
1201 | # SELECT mother.* FROM person mother |
1202 | # JOIN ( |
1203 | # person child |
1204 | # JOIN person father |
1205 | # ON ( father.person_id = child.father_id ) |
1206 | # ) |
1207 | # ON ( mother.person_id = child.mother_id ) |
1208 | |
1209 | The type of any join can be controlled manually. To search against only people |
1210 | with a father in the person table, we could explicitly use C<INNER JOIN>: |
1211 | |
1212 | $rs = $schema->resultset('Person')->search( |
5e8b1b2a |
1213 | undef, |
4a28c340 |
1214 | { |
1215 | alias => 'child', # alias columns in accordance with "from" |
1216 | from => [ |
1217 | { child => 'person' }, |
1218 | [ |
1219 | { father => 'person', -join-type => 'inner' }, |
1220 | { 'father.id' => 'child.father_id' } |
1221 | ], |
1222 | ] |
1223 | }, |
1224 | ); |
1225 | |
1226 | # Equivalent SQL: |
1227 | # SELECT child.* FROM person child |
1228 | # INNER JOIN person father ON child.father_id = father.id |
ee38fa40 |
1229 | |
bfab575a |
1230 | =head2 page |
076652e8 |
1231 | |
a33df5d4 |
1232 | For a paged resultset, specifies which page to retrieve. Leave unset |
bfab575a |
1233 | for an unpaged resultset. |
076652e8 |
1234 | |
bfab575a |
1235 | =head2 rows |
076652e8 |
1236 | |
4a28c340 |
1237 | For a paged resultset, how many rows per page: |
1238 | |
1239 | rows => 10 |
1240 | |
1241 | Can also be used to simulate an SQL C<LIMIT>. |
076652e8 |
1242 | |
87c4e602 |
1243 | =head2 group_by |
1244 | |
1245 | =head3 Arguments: (arrayref) |
54540863 |
1246 | |
bda4c2b8 |
1247 | A arrayref of columns to group by. Can include columns of joined tables. |
54540863 |
1248 | |
675ce4a6 |
1249 | group_by => [qw/ column1 column2 ... /] |
1250 | |
54540863 |
1251 | =head2 distinct |
1252 | |
a33df5d4 |
1253 | Set to 1 to group by all columns. |
1254 | |
1255 | For more examples of using these attributes, see |
1256 | L<DBIx::Class::Manual::Cookbook>. |
54540863 |
1257 | |
bfab575a |
1258 | =cut |
076652e8 |
1259 | |
89c0a5a2 |
1260 | 1; |