Am 08.04.2010 22:39, schrieb Peter Rabbitson:
> Show the actual SQL - I'll be able to answer this.
The actual SQL is rather big, so I'm using the well known KISS CD
database example.
Meanwhile I found out, that the resultset attribute "rows" is
"responsible" for switching to the big SQL code:
Without "rows":
my $artist_rs = $schema->resultset('Artist');
my $new_rs = $artist_rs->search(
undef, {
prefetch => 'cds',
}
);
while (my $artist = $new_rs->next) {
say $artist->name;
my $cd_rs = $artist->cds;
while (my $cd = $cd_rs->next) {
say "\t", $cd->title;
}
}
SELECT me.id, me.name, cds.id, cds.artist_id, cds.title
FROM artist me
LEFT JOIN cd cds ON cds.artist_id = me.id
ORDER BY cds.artist_id
With "rows":
my $new_rs = $artist_rs->search(
undef, {
prefetch => 'cds',
rows => 2,
}
);
[...]
SELECT me.id, me.name, cds.id, cds.artist_id, cds.title
FROM (
SELECT me.id, me.name
FROM artist me
GROUP BY me.id, me.name
LIMIT 2
) me
LEFT JOIN cd cds ON cds.artist_id = me.id
ORDER BY cds.artist_id
I could send you the complete archive (which is similar to manual page
DBIx::Class::Manual::Example) with the test db and scripts if it helps.
Bernhard Graf
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