1DBIx::Class::Helper::ReUssuelrtSCeotn:t:rRiabnudtoemdD(B3PI)exr:l:CDloacsusm:e:nHtealtpieorn::ResultSet::Random(3)
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NAME

6       DBIx::Class::Helper::ResultSet::Random - Get random rows from a
7       ResultSet
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SYNOPSIS

10        # note that this is normally a component for a ResultSet
11        package MySchema::ResultSet::Bar;
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13        use strict;
14        use warnings;
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16        use parent 'DBIx::Class::ResultSet';
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18        __PACKAGE__->load_components('Helper::ResultSet::Random');
19
20        # in code using resultset:
21        my $random_row  = $schema->resultset('Bar')->rand->single;
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DESCRIPTION

24       This component allows convenient selection of random rows.  See "NOTE"
25       in DBIx::Class::Helper::ResultSet for a nice way to apply it to your
26       entire schema.
27
28       Currently this works by doing something akin to
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30        SELECT TOP($x) from $table ORDER BY RANDOM()
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32       Lots of people think this is slow.  My own benchmarks show that doing
33       the above, for 10 rows in a table with just over 8 million rows, is
34       nearly instant.  Although that was with SQL Server, and different
35       databases will handle that differently.
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37       So please, if you have performance issues and want this to work with
38       your database, get in touch and I will do what I can to get it to work
39       quickly enough to suite your needs.
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METHODS

42   rand
43       This method takes a single argument, being the size of the random
44       ResultSet to return.  It defaults to 1.  This Component will throw
45       exceptions if the argument is not an integer or not greater than zero.
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47   _rand_order_by
48       This module currently does an "ORDER BY" on some db specific function.
49       If for some reason it guesses incorrectly for your database the easiest
50       way to fix that in the short-term (ie without patching upstream) is to
51       override this method.  So for example, if your db uses "RAND()" instead
52       of "RANDOM()" and it's not in the predefined list of dbs you could just
53       do the following in your ResultSet class:
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55        sub _rand_order_by { 'RAND()' }
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AUTHOR

58       Arthur Axel "fREW" Schmidt <frioux+cpan@gmail.com>
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61       This software is copyright (c) 2020 by Arthur Axel "fREW" Schmidt.
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63       This is free software; you can redistribute it and/or modify it under
64       the same terms as the Perl 5 programming language system itself.
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68perl v5.34.0                      2021D-B0I7x-:2:2Class::Helper::ResultSet::Random(3)
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