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1 | package SQL::Translator::Schema::Constraint; |
2 | |
3 | # ---------------------------------------------------------------------- |
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4 | # $Id: Constraint.pm,v 1.2 2003-05-05 04:32:39 kycl4rk Exp $ |
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5 | # ---------------------------------------------------------------------- |
6 | # Copyright (C) 2003 Ken Y. Clark <kclark@cpan.org> |
7 | # |
8 | # This program is free software; you can redistribute it and/or |
9 | # modify it under the terms of the GNU General Public License as |
10 | # published by the Free Software Foundation; version 2. |
11 | # |
12 | # This program is distributed in the hope that it will be useful, but |
13 | # WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
15 | # General Public License for more details. |
16 | # |
17 | # You should have received a copy of the GNU General Public License |
18 | # along with this program; if not, write to the Free Software |
19 | # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
20 | # 02111-1307 USA |
21 | # ------------------------------------------------------------------- |
22 | |
23 | =pod |
24 | |
25 | =head1 NAME |
26 | |
27 | SQL::Translator::Schema::Constraint - SQL::Translator constraint object |
28 | |
29 | =head1 SYNOPSIS |
30 | |
31 | use SQL::Translator::Schema::Constraint; |
32 | my $constraint = SQL::Translator::Schema::Constraint->new( |
33 | name => 'foo', |
34 | fields => [ id ], |
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35 | type => PRIMARY_KEY, |
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36 | ); |
37 | |
38 | =head1 DESCRIPTION |
39 | |
40 | C<SQL::Translator::Schema::Constraint> is the constraint object. |
41 | |
42 | =head1 METHODS |
43 | |
44 | =cut |
45 | |
46 | use strict; |
47 | use Class::Base; |
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48 | use SQL::Translator::Schema::Constants; |
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49 | |
50 | use base 'Class::Base'; |
51 | use vars qw($VERSION $TABLE_COUNT $VIEW_COUNT); |
52 | |
53 | $VERSION = 1.00; |
54 | |
55 | use constant VALID_TYPE => { |
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56 | PRIMARY_KEY, 1, |
57 | UNIQUE, 1, |
58 | CHECK_C, 1, |
59 | FOREIGN_KEY, 1, |
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60 | }; |
61 | |
62 | # ---------------------------------------------------------------------- |
63 | sub init { |
64 | |
65 | =pod |
66 | |
67 | =head2 new |
68 | |
69 | Object constructor. |
70 | |
71 | my $schema = SQL::Translator::Schema::Constraint->new( |
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72 | table => $table, # the table to which it belongs |
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73 | type => 'foreign_key', # type of table constraint |
74 | name => 'fk_phone_id', # the name of the constraint |
75 | fields => 'phone_id', # the field in the referring table |
76 | reference_fields => 'phone_id', # the referenced table |
77 | reference_table => 'phone', # the referenced fields |
78 | match_type => 'full', # how to match |
79 | on_delete_do => 'cascade', # what to do on deletes |
80 | on_update_do => '', # what to do on updates |
81 | ); |
82 | |
83 | =cut |
84 | |
85 | my ( $self, $config ) = @_; |
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86 | # match_type on_delete_do on_update_do |
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87 | my @fields = qw[ name type fields reference_fields reference_table table ]; |
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88 | |
89 | for my $arg ( @fields ) { |
90 | next unless $config->{ $arg }; |
91 | $self->$arg( $config->{ $arg } ) or return; |
92 | } |
93 | |
94 | return $self; |
95 | } |
96 | |
97 | # ---------------------------------------------------------------------- |
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98 | sub deferrable { |
99 | |
100 | =pod |
101 | |
102 | =head2 deferrable |
103 | |
104 | Get or set the whether the constraint is deferrable. If not defined, |
105 | then returns "1." The argument is evaluated by Perl for True or |
106 | False, so the following are eqivalent: |
107 | |
108 | $deferrable = $field->deferrable(0); |
109 | $deferrable = $field->deferrable(''); |
110 | $deferrable = $field->deferrable('0'); |
111 | |
112 | =cut |
113 | |
114 | my ( $self, $arg ) = @_; |
115 | |
116 | if ( defined $arg ) { |
117 | $self->{'deferrable'} = $arg ? 1 : 0; |
118 | } |
119 | |
120 | return defined $self->{'deferrable'} ? $self->{'deferrable'} : 1; |
121 | } |
122 | |
123 | # ---------------------------------------------------------------------- |
124 | sub expression { |
125 | |
126 | =pod |
127 | |
128 | =head2 expression |
129 | |
130 | Gets and set the expression used in a CHECK constraint. |
131 | |
132 | my $expression = $constraint->expression('...'); |
133 | |
134 | =cut |
135 | |
136 | my $self = shift; |
137 | |
138 | if ( my $arg = shift ) { |
139 | # check arg here? |
140 | $self->{'expression'} = $arg; |
141 | } |
142 | |
143 | return $self->{'expression'} || ''; |
144 | } |
145 | |
146 | # ---------------------------------------------------------------------- |
147 | sub is_valid { |
148 | |
149 | =pod |
150 | |
151 | =head2 is_valid |
152 | |
153 | Determine whether the constraint is valid or not. |
154 | |
155 | my $ok = $constraint->is_valid; |
156 | |
157 | =cut |
158 | |
159 | my $self = shift; |
160 | my $type = $self->type or return $self->error('No type'); |
161 | my $table = $self->table or return $self->error('No table'); |
162 | my @fields = $self->fields or return $self->error('No fields'); |
163 | my $table_name = $table->name or return $self->error('No table name'); |
164 | |
165 | for my $f ( @fields ) { |
166 | next if $table->get_field( $f ); |
167 | return $self->error( |
168 | "Constraint references non-existent field '$f' ", |
169 | "in table '$table_name'" |
170 | ); |
171 | } |
172 | |
173 | my $schema = $table->schema or return $self->error( |
174 | 'Table ', $table->name, ' has no schema object' |
175 | ); |
176 | |
177 | if ( $type eq FOREIGN_KEY ) { |
178 | return $self->error('Only one field allowed for foreign key') |
179 | if scalar @fields > 1; |
180 | |
181 | my $ref_table_name = $self->reference_table or |
182 | return $self->error('No reference table'); |
183 | |
184 | my $ref_table = $schema->get_table( $ref_table_name ) or |
185 | return $self->error("No table named '$ref_table_name' in schema"); |
186 | |
187 | my @ref_fields = $self->reference_fields or return; |
188 | |
189 | return $self->error('Only one field allowed for foreign key reference') |
190 | if scalar @ref_fields > 1; |
191 | |
192 | for my $ref_field ( @ref_fields ) { |
193 | next if $ref_table->get_field( $ref_field ); |
194 | return $self->error( |
195 | "Constraint from field(s) ", |
196 | join(', ', map {qq['$table_name.$_']} @fields), |
197 | " to non-existent field '$ref_table_name.$ref_field'" |
198 | ); |
199 | } |
200 | } |
201 | elsif ( $type eq CHECK_C ) { |
202 | return $self->error('No expression for CHECK') unless |
203 | $self->expression; |
204 | } |
205 | |
206 | return 1; |
207 | } |
208 | |
209 | # ---------------------------------------------------------------------- |
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210 | sub fields { |
211 | |
212 | =pod |
213 | |
214 | =head2 fields |
215 | |
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216 | Gets and set the fields the constraint is on. Accepts a string, list or |
217 | arrayref; returns an array or array reference. Will unique the field |
218 | names and keep them in order by the first occurrence of a field name. |
219 | |
220 | $constraint->fields('id'); |
221 | $constraint->fields('id', 'name'); |
222 | $constraint->fields( 'id, name' ); |
223 | $constraint->fields( [ 'id', 'name' ] ); |
224 | $constraint->fields( qw[ id name ] ); |
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225 | |
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226 | my @fields = $constraint->fields; |
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227 | |
228 | =cut |
229 | |
230 | my $self = shift; |
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231 | my $fields = UNIVERSAL::isa( $_[0], 'ARRAY' ) |
232 | ? shift : [ map { s/^\s+|\s+$//g; $_ } map { split /,/ } @_ ]; |
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233 | |
234 | if ( @$fields ) { |
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235 | my ( %unique, @unique ); |
236 | for my $f ( @$fields ) { |
237 | next if $unique{ $f }; |
238 | $unique{ $f } = 1; |
239 | push @unique, $f; |
240 | } |
241 | |
242 | $self->{'fields'} = \@unique; |
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243 | } |
244 | |
245 | return wantarray ? @{ $self->{'fields'} || [] } : $self->{'fields'}; |
246 | } |
247 | |
248 | # ---------------------------------------------------------------------- |
249 | sub name { |
250 | |
251 | =pod |
252 | |
253 | =head2 name |
254 | |
255 | Get or set the constraint's name. |
256 | |
257 | my $name = $constraint->name('foo'); |
258 | |
259 | =cut |
260 | |
261 | my $self = shift; |
262 | $self->{'name'} = shift if @_; |
263 | return $self->{'name'} || ''; |
264 | } |
265 | |
266 | # ---------------------------------------------------------------------- |
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267 | sub on_delete { |
268 | |
269 | =pod |
270 | |
271 | =head2 on_delete |
272 | |
273 | Get or set the constraint's "on delete" action. |
274 | |
275 | my $action = $constraint->on_delete('cascade'); |
276 | |
277 | =cut |
278 | |
279 | my $self = shift; |
280 | |
281 | if ( my $arg = shift ) { |
282 | # validate $arg? |
283 | $self->{'on_delete'} = $arg; |
284 | } |
285 | |
286 | return $self->{'on_delete'} || ''; |
287 | } |
288 | |
289 | # ---------------------------------------------------------------------- |
290 | sub on_update { |
291 | |
292 | =pod |
293 | |
294 | =head2 on_update |
295 | |
296 | Get or set the constraint's "on update" action. |
297 | |
298 | my $action = $constraint->on_update('no action'); |
299 | |
300 | =cut |
301 | |
302 | my $self = shift; |
303 | |
304 | if ( my $arg = shift ) { |
305 | # validate $arg? |
306 | $self->{'on_update'} = $arg; |
307 | } |
308 | |
309 | return $self->{'on_update'} || ''; |
310 | } |
311 | |
312 | # ---------------------------------------------------------------------- |
313 | sub reference_fields { |
314 | |
315 | =pod |
316 | |
317 | =head2 reference_fields |
318 | |
319 | Gets and set the fields in the referred table. Accepts a string, list or |
320 | arrayref; returns an array or array reference. |
321 | |
322 | $constraint->reference_fields('id'); |
323 | $constraint->reference_fields('id', 'name'); |
324 | $constraint->reference_fields( 'id, name' ); |
325 | $constraint->reference_fields( [ 'id', 'name' ] ); |
326 | $constraint->reference_fields( qw[ id name ] ); |
327 | |
328 | my @reference_fields = $constraint->reference_fields; |
329 | |
330 | =cut |
331 | |
332 | my $self = shift; |
333 | my $fields = UNIVERSAL::isa( $_[0], 'ARRAY' ) |
334 | ? shift : [ map { s/^\s+|\s+$//g; $_ } map { split /,/ } @_ ]; |
335 | |
336 | if ( @$fields ) { |
337 | $self->{'reference_fields'} = $fields; |
338 | } |
339 | |
340 | unless ( ref $self->{'reference_fields'} ) { |
341 | my $table = $self->table or return $self->error('No table'); |
342 | my $schema = $table->schema or return $self->error('No schema'); |
343 | my $ref_table_name = $self->reference_table or |
344 | return $self->error('No table'); |
345 | my $ref_table = $schema->get_table( $ref_table_name ) or |
346 | return $self->error("Can't find table '$ref_table_name'"); |
347 | |
348 | if ( my $constraint = $ref_table->primary_key ) { |
349 | $self->{'reference_fields'} = [ $constraint->fields ]; |
350 | } |
351 | else { |
352 | $self->error( |
353 | 'No reference fields defined and cannot find primary key in ', |
354 | "reference table '$ref_table_name'" |
355 | ); |
356 | } |
357 | } |
358 | |
359 | if ( ref $self->{'reference_fields'} ) { |
360 | return wantarray |
361 | ? @{ $self->{'reference_fields'} || [] } |
362 | : $self->{'reference_fields'}; |
363 | } |
364 | else { |
365 | return wantarray ? () : []; |
366 | } |
367 | } |
368 | |
369 | # ---------------------------------------------------------------------- |
370 | sub reference_table { |
371 | |
372 | =pod |
373 | |
374 | =head2 reference_table |
375 | |
376 | Get or set the table referred to by the constraint. |
377 | |
378 | my $reference_table = $constraint->reference_table('foo'); |
379 | |
380 | =cut |
381 | |
382 | my $self = shift; |
383 | $self->{'reference_table'} = shift if @_; |
384 | return $self->{'reference_table'} || ''; |
385 | } |
386 | |
387 | |
388 | # ---------------------------------------------------------------------- |
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389 | sub type { |
390 | |
391 | =pod |
392 | |
393 | =head2 type |
394 | |
395 | Get or set the constraint's type. |
396 | |
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397 | my $type = $constraint->type( PRIMARY_KEY ); |
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398 | |
399 | =cut |
400 | |
401 | my $self = shift; |
402 | |
403 | if ( my $type = shift ) { |
404 | return $self->error("Invalid constraint type: $type") |
405 | unless VALID_TYPE->{ $type }; |
406 | $self->{'type'} = $type; |
407 | } |
408 | |
409 | return $self->{'type'} || ''; |
410 | } |
411 | |
412 | |
413 | # ---------------------------------------------------------------------- |
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414 | sub table { |
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415 | |
416 | =pod |
417 | |
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418 | =head2 table |
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419 | |
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420 | Get or set the field's table object. |
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421 | |
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422 | my $table = $field->table; |
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423 | |
424 | =cut |
425 | |
426 | my $self = shift; |
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427 | if ( my $arg = shift ) { |
428 | return $self->error('Not a table object') unless |
429 | UNIVERSAL::isa( $arg, 'SQL::Translator::Schema::Table' ); |
430 | $self->{'table'} = $arg; |
431 | } |
432 | |
433 | return $self->{'table'}; |
434 | } |
435 | |
436 | # ---------------------------------------------------------------------- |
437 | sub options { |
438 | |
439 | =pod |
440 | |
441 | =head2 options |
442 | |
443 | Gets or adds to the constraints's options (e.g., "INITIALLY IMMEDIATE"). |
444 | Returns an array or array reference. |
445 | |
446 | $constraint->options('NORELY'); |
447 | my @options = $constraint->options; |
448 | |
449 | =cut |
450 | |
451 | my $self = shift; |
452 | my $options = UNIVERSAL::isa( $_[0], 'ARRAY' ) |
453 | ? shift : [ map { s/^\s+|\s+$//g; $_ } map { split /,/ } @_ ]; |
454 | |
455 | push @{ $self->{'options'} }, @$options; |
456 | |
457 | if ( ref $self->{'options'} ) { |
458 | return wantarray ? @{ $self->{'options'} || [] } : $self->{'options'}; |
459 | } |
460 | else { |
461 | return wantarray ? () : []; |
462 | } |
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463 | } |
464 | |
465 | 1; |
466 | |
467 | # ---------------------------------------------------------------------- |
468 | |
469 | =pod |
470 | |
471 | =head1 AUTHOR |
472 | |
473 | Ken Y. Clark E<lt>kclark@cpan.orgE<gt> |
474 | |
475 | =cut |