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1 | =head1 NAME |
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2 | |
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3 | DBIx::Class::Manual::Cookbook - Miscellaneous recipes |
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4 | |
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5 | =head1 RECIPES |
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6 | |
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7 | =head2 Searching |
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8 | |
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9 | =head3 Paged results |
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10 | |
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11 | When you expect a large number of results, you can ask L<DBIx::Class> for a |
12 | paged resultset, which will fetch only a small number of records at a time: |
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13 | |
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14 | my $rs = $schema->resultset('Artist')->search( |
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15 | undef, |
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16 | { |
17 | page => 1, # page to return (defaults to 1) |
18 | rows => 10, # number of results per page |
19 | }, |
20 | ); |
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21 | |
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22 | return $rs->all(); # all records for page 1 |
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23 | |
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24 | The C<page> attribute does not have to be specified in your search: |
25 | |
26 | my $rs = $schema->resultset('Artist')->search( |
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27 | undef, |
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28 | { |
29 | rows => 10, |
30 | } |
31 | ); |
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32 | |
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33 | return $rs->page(1); # DBIx::Class::ResultSet containing first 10 records |
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34 | |
35 | In either of the above cases, you can return a L<Data::Page> object for the |
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36 | resultset (suitable for use in e.g. a template) using the C<pager> method: |
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37 | |
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38 | return $rs->pager(); |
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39 | |
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40 | =head3 Complex WHERE clauses |
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41 | |
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42 | Sometimes you need to formulate a query using specific operators: |
43 | |
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44 | my @albums = $schema->resultset('Album')->search({ |
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45 | artist => { 'like', '%Lamb%' }, |
46 | title => { 'like', '%Fear of Fours%' }, |
47 | }); |
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48 | |
49 | This results in something like the following C<WHERE> clause: |
50 | |
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51 | WHERE artist LIKE '%Lamb%' AND title LIKE '%Fear of Fours%' |
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52 | |
53 | Other queries might require slightly more complex logic: |
54 | |
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55 | my @albums = $schema->resultset('Album')->search({ |
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56 | -or => [ |
57 | -and => [ |
58 | artist => { 'like', '%Smashing Pumpkins%' }, |
59 | title => 'Siamese Dream', |
60 | ], |
61 | artist => 'Starchildren', |
62 | ], |
63 | }); |
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64 | |
65 | This results in the following C<WHERE> clause: |
66 | |
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67 | WHERE ( artist LIKE '%Smashing Pumpkins%' AND title = 'Siamese Dream' ) |
68 | OR artist = 'Starchildren' |
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69 | |
70 | For more information on generating complex queries, see |
71 | L<SQL::Abstract/WHERE CLAUSES>. |
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72 | |
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73 | =head3 Using specific columns |
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74 | |
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75 | When you only want selected columns from a table, you can use C<cols> to |
76 | specify which ones you need: |
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77 | |
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78 | my $rs = $schema->resultset('Artist')->search( |
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79 | undef, |
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80 | { |
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81 | columns => [qw/ name /] |
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82 | } |
83 | ); |
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84 | |
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85 | # Equivalent SQL: |
86 | # SELECT artist.name FROM artist |
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87 | |
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88 | =head3 Using database functions or stored procedures |
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89 | |
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90 | The combination of C<select> and C<as> can be used to return the result of a |
91 | database function or stored procedure as a column value. You use C<select> to |
92 | specify the source for your column value (e.g. a column name, function, or |
93 | stored procedure name). You then use C<as> to set the column name you will use |
94 | to access the returned value: |
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95 | |
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96 | my $rs = $schema->resultset('Artist')->search( |
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97 | undef, |
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98 | { |
99 | select => [ 'name', { LENGTH => 'name' } ], |
100 | as => [qw/ name name_length /], |
101 | } |
102 | ); |
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103 | |
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104 | # Equivalent SQL: |
105 | # SELECT name name, LENGTH( name ) name_length |
106 | # FROM artist |
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107 | |
108 | If your alias exists as a column in your base class (i.e. it was added with |
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109 | C<add_columns>), you just access it as normal. Our C<Artist> class has a C<name> |
110 | column, so we just use the C<name> accessor: |
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111 | |
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112 | my $artist = $rs->first(); |
113 | my $name = $artist->name(); |
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114 | |
115 | If on the other hand the alias does not correspond to an existing column, you |
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116 | can get the value using the C<get_column> accessor: |
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117 | |
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118 | my $name_length = $artist->get_column('name_length'); |
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119 | |
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120 | If you don't like using C<get_column>, you can always create an accessor for |
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121 | any of your aliases using either of these: |
122 | |
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123 | # Define accessor manually: |
124 | sub name_length { shift->get_column('name_length'); } |
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125 | |
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126 | # Or use DBIx::Class::AccessorGroup: |
127 | __PACKAGE__->mk_group_accessors('column' => 'name_length'); |
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128 | |
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129 | =head3 SELECT DISTINCT with multiple columns |
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130 | |
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131 | my $rs = $schema->resultset('Foo')->search( |
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132 | undef, |
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133 | { |
134 | select => [ |
135 | { distinct => [ $source->columns ] } |
136 | ], |
137 | as => [ $source->columns ] |
138 | } |
139 | ); |
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140 | |
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141 | =head3 SELECT COUNT(DISTINCT colname) |
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142 | |
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143 | my $rs = $schema->resultset('Foo')->search( |
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144 | undef, |
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145 | { |
146 | select => [ |
147 | { count => { distinct => 'colname' } } |
148 | ], |
149 | as => [ 'count' ] |
150 | } |
151 | ); |
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152 | |
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153 | =head3 Grouping results |
154 | |
155 | L<DBIx::Class> supports C<GROUP BY> as follows: |
156 | |
157 | my $rs = $schema->resultset('Artist')->search( |
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158 | undef, |
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159 | { |
160 | join => [qw/ cds /], |
161 | select => [ 'name', { count => 'cds.cdid' } ], |
162 | as => [qw/ name cd_count /], |
163 | group_by => [qw/ name /] |
164 | } |
165 | ); |
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166 | |
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167 | # Equivalent SQL: |
168 | # SELECT name, COUNT( cds.cdid ) FROM artist me |
169 | # LEFT JOIN cd cds ON ( cds.artist = me.artistid ) |
170 | # GROUP BY name |
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171 | |
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172 | =head3 Predefined searches |
173 | |
174 | You can write your own DBIx::Class::ResultSet class by inheriting from it |
175 | and define often used searches as methods: |
176 | |
177 | package My::DBIC::ResultSet::CD; |
178 | use strict; |
179 | use warnings; |
180 | use base 'DBIx::Class::ResultSet'; |
181 | |
182 | sub search_cds_ordered { |
183 | my ($self) = @_; |
184 | |
185 | return $self->search( |
186 | {}, |
187 | { order_by => 'name DESC' }, |
188 | ); |
189 | } |
190 | |
191 | 1; |
192 | |
193 | To use your resultset, first tell DBIx::Class to create an instance of it |
194 | for you, in your My::DBIC::Schema::CD class: |
195 | |
196 | __PACKAGE__->resultset_class('My::DBIC::ResultSet::CD'); |
197 | |
198 | Then call your new method in your code: |
199 | |
200 | my $ordered_cds = $schema->resultset('CD')->search_cds_ordered(); |
201 | |
202 | |
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203 | =head3 Predefined searches without writing a ResultSet class |
204 | |
205 | Alternatively you can automatically generate a DBIx::Class::ResultSet |
206 | class by using the ResultSetManager component and tagging your method |
207 | as ResultSet: |
208 | |
209 | __PACKAGE__->load_components(qw/ ResultSetManager Core /); |
210 | |
211 | sub search_cds_ordered : ResultSet { |
212 | my ($self) = @_; |
213 | return $self->search( |
214 | {}, |
215 | { order_by => 'name DESC' }, |
216 | ); |
217 | } |
218 | |
219 | Then call your method in the same way from your code: |
220 | |
221 | my $ordered_cds = $schema->resultset('CD')->search_cds_ordered(); |
222 | |
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223 | =head2 Using joins and prefetch |
224 | |
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225 | You can use the C<join> attribute to allow searching on, or sorting your |
226 | results by, one or more columns in a related table. To return all CDs matching |
227 | a particular artist name: |
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228 | |
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229 | my $rs = $schema->resultset('CD')->search( |
230 | { |
231 | 'artist.name' => 'Bob Marley' |
232 | }, |
233 | { |
234 | join => [qw/artist/], # join the artist table |
235 | } |
236 | ); |
237 | |
238 | # Equivalent SQL: |
239 | # SELECT cd.* FROM cd |
240 | # JOIN artist ON cd.artist = artist.id |
241 | # WHERE artist.name = 'Bob Marley' |
242 | |
243 | If required, you can now sort on any column in the related tables by including |
244 | it in your C<order_by> attribute: |
245 | |
246 | my $rs = $schema->resultset('CD')->search( |
247 | { |
248 | 'artist.name' => 'Bob Marley' |
249 | }, |
250 | { |
251 | join => [qw/ artist /], |
252 | order_by => [qw/ artist.name /] |
253 | } |
254 | }; |
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255 | |
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256 | # Equivalent SQL: |
257 | # SELECT cd.* FROM cd |
258 | # JOIN artist ON cd.artist = artist.id |
259 | # WHERE artist.name = 'Bob Marley' |
260 | # ORDER BY artist.name |
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261 | |
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262 | Note that the C<join> attribute should only be used when you need to search or |
263 | sort using columns in a related table. Joining related tables when you only |
264 | need columns from the main table will make performance worse! |
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265 | |
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266 | Now let's say you want to display a list of CDs, each with the name of the |
267 | artist. The following will work fine: |
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268 | |
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269 | while (my $cd = $rs->next) { |
270 | print "CD: " . $cd->title . ", Artist: " . $cd->artist->name; |
271 | } |
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272 | |
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273 | There is a problem however. We have searched both the C<cd> and C<artist> tables |
274 | in our main query, but we have only returned data from the C<cd> table. To get |
275 | the artist name for any of the CD objects returned, L<DBIx::Class> will go back |
276 | to the database: |
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277 | |
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278 | SELECT artist.* FROM artist WHERE artist.id = ? |
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279 | |
280 | A statement like the one above will run for each and every CD returned by our |
281 | main query. Five CDs, five extra queries. A hundred CDs, one hundred extra |
282 | queries! |
283 | |
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284 | Thankfully, L<DBIx::Class> has a C<prefetch> attribute to solve this problem. |
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285 | This allows you to fetch results from related tables in advance: |
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286 | |
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287 | my $rs = $schema->resultset('CD')->search( |
288 | { |
289 | 'artist.name' => 'Bob Marley' |
290 | }, |
291 | { |
292 | join => [qw/ artist /], |
293 | order_by => [qw/ artist.name /], |
294 | prefetch => [qw/ artist /] # return artist data too! |
295 | } |
296 | ); |
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297 | |
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298 | # Equivalent SQL (note SELECT from both "cd" and "artist"): |
299 | # SELECT cd.*, artist.* FROM cd |
300 | # JOIN artist ON cd.artist = artist.id |
301 | # WHERE artist.name = 'Bob Marley' |
302 | # ORDER BY artist.name |
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303 | |
304 | The code to print the CD list remains the same: |
305 | |
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306 | while (my $cd = $rs->next) { |
307 | print "CD: " . $cd->title . ", Artist: " . $cd->artist->name; |
308 | } |
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309 | |
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310 | L<DBIx::Class> has now prefetched all matching data from the C<artist> table, |
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311 | so no additional SQL statements are executed. You now have a much more |
312 | efficient query. |
313 | |
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314 | Note that as of L<DBIx::Class> 0.04, C<prefetch> cannot be used with |
315 | C<has_many> relationships. You will get an error along the lines of "No |
316 | accessor for prefetched ..." if you try. |
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317 | |
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318 | Also note that C<prefetch> should only be used when you know you will |
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319 | definitely use data from a related table. Pre-fetching related tables when you |
320 | only need columns from the main table will make performance worse! |
321 | |
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322 | =head3 Multi-step joins |
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323 | |
324 | Sometimes you want to join more than one relationship deep. In this example, |
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325 | we want to find all C<Artist> objects who have C<CD>s whose C<LinerNotes> |
326 | contain a specific string: |
327 | |
328 | # Relationships defined elsewhere: |
329 | # Artist->has_many('cds' => 'CD', 'artist'); |
330 | # CD->has_one('liner_notes' => 'LinerNotes', 'cd'); |
331 | |
332 | my $rs = $schema->resultset('Artist')->search( |
333 | { |
334 | 'liner_notes.notes' => { 'like', '%some text%' }, |
335 | }, |
336 | { |
337 | join => { |
338 | 'cds' => 'liner_notes' |
339 | } |
340 | } |
341 | ); |
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342 | |
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343 | # Equivalent SQL: |
344 | # SELECT artist.* FROM artist |
345 | # JOIN ( cd ON artist.id = cd.artist ) |
346 | # JOIN ( liner_notes ON cd.id = liner_notes.cd ) |
347 | # WHERE liner_notes.notes LIKE '%some text%' |
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348 | |
349 | Joins can be nested to an arbitrary level. So if we decide later that we |
350 | want to reduce the number of Artists returned based on who wrote the liner |
351 | notes: |
352 | |
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353 | # Relationship defined elsewhere: |
354 | # LinerNotes->belongs_to('author' => 'Person'); |
355 | |
356 | my $rs = $schema->resultset('Artist')->search( |
357 | { |
358 | 'liner_notes.notes' => { 'like', '%some text%' }, |
359 | 'author.name' => 'A. Writer' |
360 | }, |
361 | { |
362 | join => { |
363 | 'cds' => { |
364 | 'liner_notes' => 'author' |
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365 | } |
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366 | } |
367 | } |
368 | ); |
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369 | |
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370 | # Equivalent SQL: |
371 | # SELECT artist.* FROM artist |
372 | # JOIN ( cd ON artist.id = cd.artist ) |
373 | # JOIN ( liner_notes ON cd.id = liner_notes.cd ) |
374 | # JOIN ( author ON author.id = liner_notes.author ) |
375 | # WHERE liner_notes.notes LIKE '%some text%' |
376 | # AND author.name = 'A. Writer' |
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377 | |
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378 | =head2 Multi-step prefetch |
379 | |
380 | From 0.04999_05 onwards, C<prefetch> can be nested more than one relationship |
381 | deep using the same syntax as a multi-step join: |
382 | |
383 | my $rs = $schema->resultset('Tag')->search( |
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384 | undef, |
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385 | { |
386 | prefetch => { |
387 | cd => 'artist' |
388 | } |
389 | } |
390 | ); |
391 | |
392 | # Equivalent SQL: |
393 | # SELECT tag.*, cd.*, artist.* FROM tag |
394 | # JOIN cd ON tag.cd = cd.cdid |
395 | # JOIN artist ON cd.artist = artist.artistid |
396 | |
397 | Now accessing our C<cd> and C<artist> relationships does not need additional |
398 | SQL statements: |
399 | |
400 | my $tag = $rs->first; |
401 | print $tag->cd->artist->name; |
402 | |
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403 | =head2 Transactions |
404 | |
405 | As of version 0.04001, there is improved transaction support in |
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406 | L<DBIx::Class::Storage::DBI> and L<DBIx::Class::Schema>. Here is an |
407 | example of the recommended way to use it: |
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408 | |
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409 | my $genus = $schema->resultset('Genus')->find(12); |
410 | |
411 | my $coderef1 = sub { |
412 | my ($schema, $genus, $code) = @_; |
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413 | $genus->add_to_species({ name => 'troglodyte' }); |
414 | $genus->wings(2); |
415 | $genus->update; |
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416 | $schema->txn_do($code, $genus); # Can have a nested transaction |
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417 | return $genus->species; |
418 | }; |
419 | |
420 | my $coderef2 = sub { |
421 | my ($genus) = @_; |
422 | $genus->extinct(1); |
423 | $genus->update; |
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424 | }; |
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425 | |
426 | my $rs; |
427 | eval { |
428 | $rs = $schema->txn_do($coderef1, $schema, $genus, $coderef2); |
429 | }; |
430 | |
431 | if ($@) { # Transaction failed |
432 | die "the sky is falling!" # |
433 | if ($@ =~ /Rollback failed/); # Rollback failed |
434 | |
435 | deal_with_failed_transaction(); |
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436 | } |
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437 | |
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438 | Nested transactions will work as expected. That is, only the outermost |
439 | transaction will actually issue a commit to the $dbh, and a rollback |
440 | at any level of any transaction will cause the entire nested |
441 | transaction to fail. Support for savepoints and for true nested |
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442 | transactions (for databases that support them) will hopefully be added |
443 | in the future. |
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444 | |
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445 | =head2 Many-to-many relationships |
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446 | |
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447 | This is straightforward using L<DBIx::Class::Relationship::ManyToMany>: |
448 | |
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449 | package My::DB; |
450 | # ... set up connection ... |
451 | |
452 | package My::User; |
453 | use base 'My::DB'; |
454 | __PACKAGE__->table('user'); |
455 | __PACKAGE__->add_columns(qw/id name/); |
456 | __PACKAGE__->set_primary_key('id'); |
457 | __PACKAGE__->has_many('user_address' => 'My::UserAddress', 'user'); |
458 | __PACKAGE__->many_to_many('addresses' => 'user_address', 'address'); |
459 | |
460 | package My::UserAddress; |
461 | use base 'My::DB'; |
462 | __PACKAGE__->table('user_address'); |
463 | __PACKAGE__->add_columns(qw/user address/); |
464 | __PACKAGE__->set_primary_key(qw/user address/); |
465 | __PACKAGE__->belongs_to('user' => 'My::User'); |
466 | __PACKAGE__->belongs_to('address' => 'My::Address'); |
467 | |
468 | package My::Address; |
469 | use base 'My::DB'; |
470 | __PACKAGE__->table('address'); |
471 | __PACKAGE__->add_columns(qw/id street town area_code country/); |
472 | __PACKAGE__->set_primary_key('id'); |
473 | __PACKAGE__->has_many('user_address' => 'My::UserAddress', 'address'); |
474 | __PACKAGE__->many_to_many('users' => 'user_address', 'user'); |
475 | |
476 | $rs = $user->addresses(); # get all addresses for a user |
477 | $rs = $address->users(); # get all users for an address |
478 | |
479 | =head2 Setting default values for a row |
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480 | |
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481 | It's as simple as overriding the C<new> method. Note the use of |
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482 | C<next::method>. |
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483 | |
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484 | sub new { |
485 | my ( $class, $attrs ) = @_; |
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486 | |
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487 | $attrs->{foo} = 'bar' unless defined $attrs->{foo}; |
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488 | |
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489 | $class->next::method($attrs); |
490 | } |
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491 | |
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492 | For more information about C<next::method>, look in the L<Class::C3> |
493 | documentation. See also L<DBIx::Class::Manual::Component> for more |
494 | ways to write your own base classes to do this. |
495 | |
496 | People looking for ways to do "triggers" with DBIx::Class are probably |
497 | just looking for this. |
498 | |
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499 | =head2 Stringification |
500 | |
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501 | Employ the standard stringification technique by using the C<overload> |
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502 | module. Replace C<foo> with the column/method of your choice. |
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503 | |
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504 | use overload '""' => 'foo', fallback => 1; |
25af00d7 |
505 | |
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506 | =head2 Disconnecting cleanly |
507 | |
508 | If you find yourself quitting an app with Control-C a lot during |
509 | development, you might like to put the following signal handler in |
510 | your main database class to make sure it disconnects cleanly: |
511 | |
512 | $SIG{INT} = sub { |
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513 | __PACKAGE__->storage->disconnect; |
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514 | }; |
515 | |
362500af |
516 | =head2 Schema import/export |
517 | |
518 | This functionality requires you to have L<SQL::Translator> (also known as |
519 | "SQL Fairy") installed. |
520 | |
521 | To create a DBIx::Class schema from an existing database: |
522 | |
523 | sqlt --from DBI |
524 | --to DBIx::Class::File |
525 | --prefix "MySchema" > MySchema.pm |
526 | |
527 | To create a MySQL database from an existing L<DBIx::Class> schema, convert the |
528 | schema to MySQL's dialect of SQL: |
529 | |
530 | sqlt --from DBIx::Class --to MySQL --DBIx::Class "MySchema.pm" > Schema1.sql |
531 | |
532 | And import using the mysql client: |
533 | |
534 | mysql -h "host" -D "database" -u "user" -p < Schema1.sql |
535 | |
b0a20454 |
536 | =head2 Easy migration from class-based to schema-based setup |
537 | |
538 | You want to start using the schema-based approach to L<DBIx::Class> |
539 | (see L<SchemaIntro.pod>), but have an established class-based setup with lots |
540 | of existing classes that you don't want to move by hand. Try this nifty script |
541 | instead: |
542 | |
543 | use MyDB; |
544 | use SQL::Translator; |
545 | |
546 | my $schema = MyDB->schema_instance; |
547 | |
548 | my $translator = SQL::Translator->new( |
549 | debug => $debug || 0, |
550 | trace => $trace || 0, |
551 | no_comments => $no_comments || 0, |
552 | show_warnings => $show_warnings || 0, |
553 | add_drop_table => $add_drop_table || 0, |
554 | validate => $validate || 0, |
555 | parser_args => { |
556 | 'DBIx::Schema' => $schema, |
c5f36986 |
557 | }, |
b0a20454 |
558 | producer_args => { |
559 | 'prefix' => 'My::Schema', |
c5f36986 |
560 | }, |
b0a20454 |
561 | ); |
562 | |
563 | $translator->parser('DBIx::Class'); |
564 | $translator->producer('DBIx::Class::File'); |
565 | |
566 | my $output = $translator->translate(@args) or die |
567 | "Error: " . $translator->error; |
568 | |
569 | print $output; |
570 | |
571 | You could use L<Module::Find> to search for all subclasses in the MyDB::* |
880a1a0c |
572 | namespace, which is currently left as an exercise for the reader. |
b0a20454 |
573 | |
362500af |
574 | =head2 Schema versioning |
575 | |
576 | The following example shows simplistically how you might use DBIx::Class to |
577 | deploy versioned schemas to your customers. The basic process is as follows: |
578 | |
da4779ad |
579 | =over 4 |
580 | |
581 | =item 1. |
582 | |
583 | Create a DBIx::Class schema |
584 | |
585 | =item 2. |
586 | |
587 | Save the schema |
588 | |
589 | =item 3. |
590 | |
591 | Deploy to customers |
592 | |
593 | =item 4. |
594 | |
595 | Modify schema to change functionality |
596 | |
597 | =item 5. |
598 | |
599 | Deploy update to customers |
600 | |
601 | =back |
362500af |
602 | |
603 | =head3 Create a DBIx::Class schema |
604 | |
605 | This can either be done manually, or generated from an existing database as |
606 | described under C<Schema import/export>. |
607 | |
608 | =head3 Save the schema |
609 | |
610 | Use C<sqlt> to transform your schema into an SQL script suitable for your |
611 | customer's database. E.g. for MySQL: |
612 | |
613 | sqlt --from DBIx::Class |
614 | --to MySQL |
615 | --DBIx::Class "MySchema.pm" > Schema1.mysql.sql |
616 | |
617 | If you need to target databases from multiple vendors, just generate an SQL |
618 | script suitable for each. To support PostgreSQL too: |
619 | |
620 | sqlt --from DBIx::Class |
621 | --to PostgreSQL |
622 | --DBIx::Class "MySchema.pm" > Schema1.pgsql.sql |
623 | |
624 | =head3 Deploy to customers |
625 | |
626 | There are several ways you could deploy your schema. These are probably |
627 | beyond the scope of this recipe, but might include: |
628 | |
da4779ad |
629 | =over 4 |
630 | |
631 | =item 1. |
632 | |
633 | Require customer to apply manually using their RDBMS. |
634 | |
635 | =item 2. |
636 | |
637 | Package along with your app, making database dump/schema update/tests |
362500af |
638 | all part of your install. |
639 | |
da4779ad |
640 | =back |
641 | |
362500af |
642 | =head3 Modify the schema to change functionality |
643 | |
644 | As your application evolves, it may be necessary to modify your schema to |
645 | change functionality. Once the changes are made to your schema in DBIx::Class, |
646 | export the modified schema as before, taking care not to overwrite the original: |
647 | |
648 | sqlt --from DBIx::Class |
649 | --to MySQL |
650 | --DBIx::Class "Anything.pm" > Schema2.mysql.sql |
651 | |
652 | Next, use sqlt-diff to create an SQL script that will update the customer's |
653 | database schema: |
654 | |
655 | sqlt-diff --to MySQL Schema1=MySQL Schema2=MySQL > SchemaUpdate.mysql.sql |
656 | |
657 | =head3 Deploy update to customers |
658 | |
659 | The schema update can be deployed to customers using the same method as before. |
660 | |
7be93b07 |
661 | =head2 Setting limit dialect for SQL::Abstract::Limit |
662 | |
663 | In some cases, SQL::Abstract::Limit cannot determine the dialect of the remote |
664 | SQL-server by looking at the database-handle. This is a common problem when |
665 | using the DBD::JDBC, since the DBD-driver only know that in has a Java-driver |
666 | available, not which JDBC-driver the Java component has loaded. |
667 | This specifically sets the limit_dialect to Microsoft SQL-server (Se more names |
668 | in SQL::Abstract::Limit -documentation. |
669 | |
670 | __PACKAGE__->storage->sql_maker->limit_dialect('mssql'); |
671 | |
672 | The JDBC-bridge is one way of getting access to a MSSQL-server from a platform |
673 | that Microsoft doesn't deliver native client libraries for. (e.g. Linux) |
674 | |
2437a1e3 |
675 | =head2 Setting quotes for the generated SQL. |
676 | |
677 | If the database contains columnames with spaces and/or reserved words, the |
678 | SQL-query needs to be quoted. This is done using: |
679 | |
680 | __PACKAGE__->storage->sql_maker->quote_char([ qw/[ ]/] ); |
681 | __PACKAGE__->storage->sql_maker->name_sep('.'); |
682 | |
683 | The first sets the quotesymbols. If the quote i "symmetric" as " or ' |
684 | |
685 | __PACKAGE__->storage->sql_maker->quote_char('"'); |
686 | |
880a1a0c |
687 | is enough. If the left quote differs form the right quote, the first |
2437a1e3 |
688 | notation should be used. name_sep needs to be set to allow the |
689 | SQL generator to put the quotes the correct place. |
690 | |
40dbc108 |
691 | =cut |