* SELECT [#g8767459]
** where句を設定する [#u5289657]
$rs->search({ age => 20 }) # WHERE age = 20 =
$rs->search({ age => {'>' => 20} }) # WHERE age > 20 >
$rs->search({ age => undef }) # WHERE age is NULL NULL
$rs->search([{ age => 20 },{ age => 30 }]) # WHERE age = 20 OR age = 30 OR
$rs->search({ age => 20, name => 'taro }) # WHERE age = 20 AND name = 'taro' AND
$rs->search({ 'age' => { '>' => 10, '<' => 20 }}) # WHERE age > 10 AND age < 20 AND 同じカラムを使う場合
$rs->search_like({ name => '%taro%' }) # WHERE name LIKE '%taro%' LIKE
$rs->search({id => {-in => \@ids}}) # WHERE id in (1,2,3..) IN
http://search.cpan.org/perldoc?DBIx::Class::ResultSet#search
** 検索を実行する [#p7adce4a]
*** 順次取り出す [#f11c67d6]
my $rs = $schema->resultset('User')->search({ age => 20});
while (my $user = $rs->next) { print $user->name; }
*** 1行だけ取り出す [#c2654ac7]
my $user = $schema->resultset('User')->single({ age => 20});
*** 最初の行を取り出す [#s12d6f89]
my $user = $schema->resultset('User')->search({ age => 20})->first;
*** 全行取り出す [#kb43997d]
my @users = $schema->resultset('User')->search({ age => 20})->all;
*** プライマリキーで検索する [#he6a13f8]
my $user = $schema->resultset('User')->find(5);
見つからないときはundefが返ってくる。
** ORDER BY [#h7a857b5]
$rs->search({},{
order_by => [ 'name', { -desc => 'id' } ] # ORDER BY name ASC, id DESC
}); # 'name' は { -asc => 'name' } の省略形
http://search.cpan.org/perldoc?SQL::Abstract#ORDER_BY_CLAUSES
*** NULLを0と見なしてORDER BYする方法 [#ec445214]
（多分）DBICではCASE式が使えないので、COALESCE関数を使う。例えばpointカラムを降順でソートするには以下のようにする。
$rs->search(undef, {
order_by => [ { '-desc' => \'COALESCE(point, 0)' } ],
});
** GROUP BY [#g35ffed7]
$rs->search({},{
select => ['name', {SUM => 'point'}],
as => ['name', 'point'],
group_by => ['name'],
});
$point = $rs->next->get_column('point');
** COUNT() [#e0e28000]
$rs = $rs->search();
print $rs->count;
↓SELECT COUNT(DISTINCT name) FROM user
$rs = $rs->seach({},{
select => [ { count => { distinct => 'name' } } ],
as => ['count'],
});
print $rs->next->get_column('count');
** LIMIT / OFFSET [#y76174dc]
$rs->search({},{ order_by => 'id' })->slice(0,20); # slice($offset,$limit)
** 特定のカラムのみSELECT（AS演算子）[#hf28370c]
$rs->search({},{
select => [ 'name', 'age' ],
as => [ 'name', '年齢'],
});
print $r->name, $r->get_column('年齢');
** ROWオブジェクトからカラム名と値を取得する [#i69066cb]
my %user_data = $user->get_columns;
*** 参考 [#uc7fd2cc]
http://search.cpan.org/perldoc?DBIx::Class::Row
** DB関数 [#r24f677f]
*** sum() [#o5ab99c5]
# SELECT sum(point) AS total_point FROM t1;
$rs = $rs->search(
{},
{
select => [ { sum => 'point' } ],
as => ['total_point'],
}
);
my $total_point = $rs->first ? $rs->first->get_column('total_point') : 0;
*** DBの関数を比較の対象に使う [#zeced0ab]
$rs->search({"date_part('year', age(now(), birth_date))" => { '<=' => 18 } }); # 年齢が18歳以下
# date_part()とage()はPostgreSQLの関数
http://search.cpan.org/perldoc?DBIx::Class::Manual::Cookbook#Using_SQL_functions_on_the_left_hand_side_of_a_comparison
*** DBの関数を比較の値に使う [#z004db0c]
不等号「>」も含めて、スカラリファレンスにする。
$rs->search( { start_day => \' > now()' } );
