DBIx::Class::Manual::Cookbook 0.08001

DBIx::Class::Manual::Cookbook is a Perl module that contains miscellaneous recipes.

Paged results

When you expect a large number of results, you can ask DBIx::Class for a paged resultset, which will fetch only a small number of records at a time:

my $rs = $schema->resultset(Artist)->search(
undef,
{
page => 1, # page to return (defaults to 1)
rows => 10, # number of results per page
},
);

return $rs->all(); # all records for page 1
The page attribute does not have to be specified in your search:
my $rs = $schema->resultset(Artist)->search(
undef,
{
rows => 10,
}
);

return $rs->page(1); # DBIx::Class::ResultSet containing first 10 records
In either of the above cases, you can return a Data::Page object for the resultset (suitable for use in e.g. a template) using the pager method:
return $rs->pager();

Complex WHERE clauses

Sometimes you need to formulate a query using specific operators:

my @albums = $schema->resultset(Album)->search({
artist => { like, %Lamb% },
title => { like, %Fear of Fours% },
});

This results in something like the following WHERE clause:

WHERE artist LIKE %Lamb% AND title LIKE %Fear of Fours%

Other queries might require slightly more complex logic:

my @albums = $schema->resultset(Album)->search({
-or => [
-and => [
artist => { like, %Smashing Pumpkins% },
title => Siamese Dream,
],
artist => Starchildren,
],
});

This results in the following WHERE clause:

WHERE ( artist LIKE %Smashing Pumpkins% AND title = Siamese Dream )
OR artist = Starchildren

For more information on generating complex queries, see "WHERE CLAUSES" in SQL::Abstract.