如何在DBIx::class中指定要加入的第三个表的列?这是我的代码:
my $join = $schema->resultset('Track')->search({'name' => 'Eminem'},{'join' => {'cd' => 'artist'}});
它只显示埃米纳姆的曲目,但我也想显示艺术家的名字,埃米纳姆?我无法访问该查询中的name
,因为这是Track的ResultSet,name
是Artist表中的一列,Artist表是联接中的第三个表。
我想你想根据艺术家名称而不是曲目名称来过滤结果集:
my $rs = $schema->resultset('Track')->search({
'artist.name' => 'Eminem',
},
{
join => { cd => 'artist' },
});
当循环遍历结果集时,您可以使用关系和列访问器来访问它:
for my $track ($rs->all) {
say $track->cd->artist->name . ' - ' . $track->name;
}
使用关系访问器。
for my $track (
$schema->resultset('Track')->search(
{
name => 'Eminem',
},
{
join => {cd => 'artist'},
}
)->all
) {
use Data::Printer;
p { $track->get_inflated_columns };
p $track->cd->artist->name;
}
__END__
{
cd MyDatabase::Main::Result::Cd {
internals: {
_column_data {
artist 2,
cdid 3,
title "The Marshall Mathers LP"
},
}
},
title "The Way I Am",
trackid 1
}
"Eminem"
{
cd MyDatabase::Main::Result::Cd {
internals: {
_column_data {
artist 2,
cdid 3,
title "The Marshall Mathers LP"
},
}
},
title "Stan",
trackid 2
}
"Eminem"