Commit | Line | Data |
2bb7b40b |
1 | package DBIx::Class::ResultSetColumn; |
2 | use strict; |
3 | use warnings; |
4 | use base 'DBIx::Class'; |
66521001 |
5 | use List::Util; |
2bb7b40b |
6 | |
7 | =head1 NAME |
8 | |
9 | DBIx::Class::ResultSetColumn - helpful methods for messing |
10 | with a single column of the resultset |
11 | |
12 | =head1 SYNOPSIS |
13 | |
14 | $rs = $schema->resultset('CD')->search({ artist => 'Tool' }); |
15 | $rs_column = $rs->get_column('year'); |
16 | $max_year = $rs_column->max; #returns latest year |
17 | |
18 | =head1 DESCRIPTION |
19 | |
eb98561c |
20 | A convenience class used to perform operations on a specific column of |
21 | a resultset. |
2bb7b40b |
22 | |
23 | =cut |
24 | |
25 | =head1 METHODS |
26 | |
27 | =head2 new |
28 | |
29 | my $obj = DBIx::Class::ResultSetColumn->new($rs, $column); |
30 | |
eb98561c |
31 | Creates a new resultset column object from the resultset and column |
32 | passed as params. Used internally by L<DBIx::Class::ResultSet/get_column>. |
2bb7b40b |
33 | |
34 | =cut |
35 | |
36 | sub new { |
37 | my ($class, $rs, $column) = @_; |
38 | $class = ref $class if ref $class; |
3f6cc7e4 |
39 | my $new_parent_rs = $rs->search_rs; # we don't want to mess up the original, so clone it |
5d1fc7dc |
40 | my $attrs = $new_parent_rs->_resolved_attrs; |
41 | $new_parent_rs->{attrs}->{$_} = undef for qw(prefetch include_columns +select +as); # prefetch, include_columns, +select, +as cause additional columns to be fetched |
b6e85b48 |
42 | |
152002c4 |
43 | # If $column can be found in the 'as' list of the parent resultset, use the |
44 | # corresponding element of its 'select' list (to keep any custom column |
45 | # definition set up with 'select' or '+select' attrs), otherwise use $column |
46 | # (to create a new column definition on-the-fly). |
b6e85b48 |
47 | my $as_list = $attrs->{as} || []; |
48 | my $select_list = $attrs->{select} || []; |
49 | my $as_index = List::Util::first { ($as_list->[$_] || "") eq $column } 0..$#$as_list; |
b6e85b48 |
50 | my $select = defined $as_index ? $select_list->[$as_index] : $column; |
51 | |
52 | my $new = bless { _select => $select, _as => $column, _parent_resultset => $new_parent_rs }, $class; |
6b051e14 |
53 | $new->throw_exception("column must be supplied") unless $column; |
2bb7b40b |
54 | return $new; |
55 | } |
56 | |
658fa250 |
57 | =head2 as_query |
58 | |
59 | =over 4 |
60 | |
61 | =item Arguments: none |
62 | |
4dc99a01 |
63 | =item Return Value: \[ $sql, @bind ] |
658fa250 |
64 | |
65 | =back |
66 | |
67 | Returns the SQL query and bind vars associated with the invocant. |
68 | |
69 | =cut |
70 | |
71 | sub as_query { return shift->_resultset->as_query } |
72 | |
c7a9d102 |
73 | =head2 as_subselect |
74 | |
75 | =over 4 |
76 | |
77 | =item Arguments: none |
78 | |
79 | =item Return Value: \[ $sql, @bind ] |
80 | |
81 | =back |
82 | |
83 | Returns the SQL query and bind vars associated with the invocant. |
84 | |
85 | The SQL will be wrapped in parentheses, ready for use as a subselect. |
86 | |
87 | =cut |
88 | |
89 | sub as_subselect { |
90 | my $self = shift; |
91 | my $arr = ${$self->as_query(@_)}; |
92 | $arr->[0] = '( ' . $arr->[0] . ' )'; |
93 | return \$arr; |
94 | } |
95 | |
96 | =head2 as_query |
97 | |
98 | =over 4 |
99 | |
100 | =item Arguments: none |
101 | |
102 | =item Return Value: $sql |
103 | |
104 | =back |
105 | |
106 | Returns the SQL query associated with the invocant. All bind vars |
107 | will have been bound using C<< DBI->quote() >>. |
108 | |
109 | =cut |
110 | |
111 | sub as_sql { |
112 | my $self = shift; |
113 | my $arr = ${$self->as_query(@_)}; |
114 | my $sql = shift @$arr; |
115 | my $dbh = $self->_resultset->result_source->schema->storage->dbh; |
116 | $sql =~ s/\?/$dbh->quote((shift @$arr)->[1])/eg; |
117 | return $sql |
118 | } |
119 | |
2bb7b40b |
120 | =head2 next |
121 | |
122 | =over 4 |
123 | |
124 | =item Arguments: none |
125 | |
126 | =item Return Value: $value |
127 | |
128 | =back |
129 | |
eb98561c |
130 | Returns the next value of the column in the resultset (or C<undef> if |
131 | there is none). |
2bb7b40b |
132 | |
eb98561c |
133 | Much like L<DBIx::Class::ResultSet/next> but just returning the |
134 | one value. |
2bb7b40b |
135 | |
136 | =cut |
137 | |
138 | sub next { |
139 | my $self = shift; |
66521001 |
140 | my ($row) = $self->_resultset->cursor->next; |
2bb7b40b |
141 | return $row; |
142 | } |
143 | |
144 | =head2 all |
145 | |
146 | =over 4 |
147 | |
148 | =item Arguments: none |
149 | |
150 | =item Return Value: @values |
151 | |
152 | =back |
153 | |
eb98561c |
154 | Returns all values of the column in the resultset (or C<undef> if |
155 | there are none). |
2bb7b40b |
156 | |
eb98561c |
157 | Much like L<DBIx::Class::ResultSet/all> but returns values rather |
158 | than row objects. |
2bb7b40b |
159 | |
160 | =cut |
161 | |
162 | sub all { |
163 | my $self = shift; |
66521001 |
164 | return map { $_->[0] } $self->_resultset->cursor->all; |
165 | } |
166 | |
167 | =head2 reset |
168 | |
169 | =over 4 |
170 | |
171 | =item Arguments: none |
172 | |
173 | =item Return Value: $self |
174 | |
175 | =back |
176 | |
177 | Resets the underlying resultset's cursor, so you can iterate through the |
178 | elements of the column again. |
179 | |
180 | Much like L<DBIx::Class::ResultSet/reset>. |
181 | |
182 | =cut |
183 | |
184 | sub reset { |
185 | my $self = shift; |
186 | $self->_resultset->cursor->reset; |
187 | return $self; |
188 | } |
189 | |
190 | =head2 first |
191 | |
192 | =over 4 |
193 | |
194 | =item Arguments: none |
195 | |
196 | =item Return Value: $value |
197 | |
198 | =back |
199 | |
200 | Resets the underlying resultset and returns the next value of the column in the |
201 | resultset (or C<undef> if there is none). |
202 | |
203 | Much like L<DBIx::Class::ResultSet/first> but just returning the one value. |
204 | |
205 | =cut |
206 | |
207 | sub first { |
208 | my $self = shift; |
3484603a |
209 | my ($row) = $self->_resultset->cursor->reset->next; |
66521001 |
210 | return $row; |
2bb7b40b |
211 | } |
212 | |
213 | =head2 min |
214 | |
215 | =over 4 |
216 | |
217 | =item Arguments: none |
218 | |
219 | =item Return Value: $lowest_value |
220 | |
221 | =back |
222 | |
eb98561c |
223 | my $first_year = $year_col->min(); |
224 | |
225 | Wrapper for ->func. Returns the lowest value of the column in the |
226 | resultset (or C<undef> if there are none). |
2bb7b40b |
227 | |
228 | =cut |
229 | |
230 | sub min { |
6b051e14 |
231 | return shift->func('MIN'); |
2bb7b40b |
232 | } |
233 | |
234 | =head2 max |
235 | |
236 | =over 4 |
237 | |
238 | =item Arguments: none |
239 | |
240 | =item Return Value: $highest_value |
241 | |
242 | =back |
243 | |
eb98561c |
244 | my $last_year = $year_col->max(); |
245 | |
246 | Wrapper for ->func. Returns the highest value of the column in the |
247 | resultset (or C<undef> if there are none). |
2bb7b40b |
248 | |
249 | =cut |
250 | |
251 | sub max { |
6b051e14 |
252 | return shift->func('MAX'); |
2bb7b40b |
253 | } |
254 | |
255 | =head2 sum |
256 | |
257 | =over 4 |
258 | |
259 | =item Arguments: none |
260 | |
261 | =item Return Value: $sum_of_values |
262 | |
263 | =back |
264 | |
eb98561c |
265 | my $total = $prices_col->sum(); |
266 | |
267 | Wrapper for ->func. Returns the sum of all the values in the column of |
268 | the resultset. Use on varchar-like columns at your own risk. |
2bb7b40b |
269 | |
270 | =cut |
271 | |
272 | sub sum { |
6b051e14 |
273 | return shift->func('SUM'); |
2bb7b40b |
274 | } |
275 | |
276 | =head2 func |
277 | |
278 | =over 4 |
279 | |
280 | =item Arguments: $function |
281 | |
282 | =item Return Value: $function_return_value |
283 | |
284 | =back |
285 | |
e8419341 |
286 | $rs = $schema->resultset("CD")->search({}); |
287 | $length = $rs->get_column('title')->func('LENGTH'); |
2bb7b40b |
288 | |
eb98561c |
289 | Runs a query using the function on the column and returns the |
290 | value. Produces the following SQL: |
291 | |
292 | SELECT LENGTH( title ) FROM cd me |
2bb7b40b |
293 | |
294 | =cut |
295 | |
296 | sub func { |
6b051e14 |
297 | my ($self,$function) = @_; |
5d1fc7dc |
298 | my $cursor = $self->{_parent_resultset}->search(undef, {select => {$function => $self->{_select}}, as => [$self->{_as}]})->cursor; |
5d62876f |
299 | |
300 | if( wantarray ) { |
301 | return map { $_->[ 0 ] } $cursor->all; |
302 | } |
303 | |
304 | return ( $cursor->next )[ 0 ]; |
2bb7b40b |
305 | } |
306 | |
5d1fc7dc |
307 | =head2 throw_exception |
308 | |
309 | See L<DBIx::Class::Schema/throw_exception> for details. |
310 | |
311 | =cut |
312 | |
313 | sub throw_exception { |
314 | my $self=shift; |
315 | if (ref $self && $self->{_parent_resultset}) { |
316 | $self->{_parent_resultset}->throw_exception(@_) |
317 | } else { |
318 | croak(@_); |
319 | } |
320 | } |
321 | |
b6e85b48 |
322 | # _resultset |
323 | # |
324 | # Arguments: none |
325 | # |
326 | # Return Value: $resultset |
327 | # |
328 | # $year_col->_resultset->next |
329 | # |
330 | # Returns the underlying resultset. Creates it from the parent resultset if |
331 | # necessary. |
332 | # |
66521001 |
333 | sub _resultset { |
334 | my $self = shift; |
335 | |
336 | return $self->{_resultset} ||= $self->{_parent_resultset}->search(undef, |
337 | { |
338 | select => [$self->{_select}], |
339 | as => [$self->{_as}] |
340 | } |
341 | ); |
342 | } |
343 | |
2bb7b40b |
344 | 1; |
345 | |
346 | =head1 AUTHORS |
347 | |
348 | Luke Saunders <luke.saunders@gmail.com> |
349 | |
eb98561c |
350 | Jess Robinson |
351 | |
2bb7b40b |
352 | =head1 LICENSE |
353 | |
354 | You may distribute this code under the same terms as Perl itself. |
355 | |
356 | =cut |