1Class::DBI::Plugin::DeeUpsAebrstCroancttrSiebaurtcehdC(l3Pa)esrsl::DDoBcIu:m:ePnltuagtiino:n:DeepAbstractSearch(3)
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6 Class::DBI::Plugin::DeepAbstractSearch - deep_search_where() for
7 Class::DBI
8
10 use base 'Class::DBI';
11 use Class::DBI::Plugin::DeepAbstractSearch;
12
13 my @cds = Music::CD->deep_search_where(
14 {
15 'artist.name' => $artist_name
16 }
17 );
18
20 This plugin provides a SQL::Abstract search method for Class::DBI. It
21 is similar to Class::DBI::AbstractSearch, but allows you to search and
22 sort by fields from joined tables.
23
24 Note: When searching and sorting by the fields of the current class
25 only, it is more efficient to use Class::DBI::AbstractSearch.
26
28 deep_search_where
29 my @cds = Music::CD->deep_search_where(
30 {
31 'artist.name' => $artist_name
32 }
33 );
34
35 This method will be exported into the calling class, and allows for
36 searching of objects using SQL::Abstract format based on fields from
37 the calling class as well as using fields in classes related through a
38 (chain of) 'has_a' relationships to the calling class.
39
40 When specifying a field in a related class, you separate it with a
41 period from the corresponding foreign key field in the primary class.
42
43 package Music::Artist;
44 use base 'Class::DBI';
45 Music::Artist->table('artist');
46 Music::Artist->columns(All => qw/artistid name/);
47 Music::Artist->has_many(cds => 'Music::CD');
48
49 package Music::CD;
50 use base 'Class::DBI';
51 Music::CD->table('cd');
52 Music::CD->columns(All => qw/cdid artist title year/);
53 Music::CD->has_many(tracks => 'Music::Track');
54 Music::CD->has_a(artist => 'Music::Artist');
55
56 package Music::Track;
57 use base 'Class::DBI';
58 Music::Track->table('track');
59 Music::Track->columns(All => qw/trackid cd position title/);
60
61 ## Tracks on all CDs with the title "Greatest Hits"
62 @tracks = Music::Track->deep_search_where(
63 {
64 'cd.title' => "Greatest Hits"
65 },
66 {
67 sort_by => 'cd.title'
68 }
69 );
70
71 ## Tracks on CDs by Willie Nelson, sorted by CD Title and Track Position
72 @tracks = Music::Track->deep_search_where(
73 {
74 'cd.artist.name' => "Willie Nelson"
75 },
76 {
77 sort_by => 'cd.title, position'
78 }
79 );
80
81 ## First 3 Tracks on CDs, whose title contains "Outlaw", by Willie Nelson
82 @tracks = Music::Track->deep_search_where(
83 {
84 'cd.artist.name' => "Willie Nelson",
85 'cd.title' => { -like => '%Outlaw%' },
86 position => { '<=' => 3 }
87 },
88 {
89 sort_by => 'cd.title, position'
90 }
91 );
92
93 count_deep_search_where
94 my $num_cds = Music::CD->count_deep_search_where(
95 {
96 'artist.name' => $artist_name
97 }
98 );
99
100 This method will be exported into the calling class, and allows for
101 counting of objects using SQL::Abstract format based on fields from the
102 calling class as well as using fields in classes related through a
103 (chain of) 'has_a' relationships to the calling class.
104
105 get_deep_where
106 my ($what, $from, $where, $bind) = $class->get_deep_where($where, $attr);
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108 This method will be exported into the calling class, and allows for
109 retrieving SQL fragments used for creating queries. The parameters are
110 the same as to deep_search_where.
111
113 Stepan Riha, "sriha@cpan.org"
114
116 Copyright (C) 2005, 2007, 2008 Stepan Riha. All rights reserved.
117
118 This module is free software; you can redistribute it and/or modify it
119 under the same terms as Perl itself.
120
122 Class::DBI, SQL::Abstract, Class::DBI::AbstractSearch
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126perl v5.32.0 2020C-l0a7s-s2:8:DBI::Plugin::DeepAbstractSearch(3)