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
The C<page> attribute does not have to be specified in your search:
my $rs = $schema->resultset('Artist')->search(
- {},
+ undef,
{
rows => 10,
}
specify which ones you need:
my $rs = $schema->resultset('Artist')->search(
- {},
+ undef,
{
- cols => [qw/ name /]
+ columns => [qw/ name /]
}
);
to access the returned value:
my $rs = $schema->resultset('Artist')->search(
- {},
+ undef,
{
select => [ 'name', { LENGTH => 'name' } ],
as => [qw/ name name_length /],
=head3 SELECT DISTINCT with multiple columns
my $rs = $schema->resultset('Foo')->search(
- {},
+ undef,
{
select => [
{ distinct => [ $source->columns ] }
=head3 SELECT COUNT(DISTINCT colname)
my $rs = $schema->resultset('Foo')->search(
- {},
+ undef,
{
select => [
{ count => { distinct => 'colname' } }
L<DBIx::Class> supports C<GROUP BY> as follows:
my $rs = $schema->resultset('Artist')->search(
- {},
+ undef,
{
join => [qw/ cds /],
select => [ 'name', { count => 'cds.cdid' } ],
# LEFT JOIN cd cds ON ( cds.artist = me.artistid )
# GROUP BY name
+=head3 Predefined searches
+
+You can write your own DBIx::Class::ResultSet class by inheriting from it
+and define often used searches as methods:
+
+ package My::DBIC::ResultSet::CD;
+ use strict;
+ use warnings;
+ use base 'DBIx::Class::ResultSet';
+
+ sub search_cds_ordered {
+ my ($self) = @_;
+
+ return $self->search(
+ {},
+ { order_by => 'name DESC' },
+ );
+ }
+
+ 1;
+
+To use your resultset, first tell DBIx::Class to create an instance of it
+for you, in your My::DBIC::Schema::CD class:
+
+ __PACKAGE__->resultset_class('My::DBIC::ResultSet::CD');
+
+Then call your new method in your code:
+
+ my $ordered_cds = $schema->resultset('CD')->search_cds_ordered();
+
+
=head2 Using joins and prefetch
You can use the C<join> attribute to allow searching on, or sorting your
deep using the same syntax as a multi-step join:
my $rs = $schema->resultset('Tag')->search(
- {},
+ undef,
{
prefetch => {
cd => 'artist'
$genus->add_to_species({ name => 'troglodyte' });
$genus->wings(2);
$genus->update;
- $schema->txn_do($code, $genus); # Can have a nested transation
+ $schema->txn_do($code, $genus); # Can have a nested transaction
return $genus->species;
};
print $output;
You could use L<Module::Find> to search for all subclasses in the MyDB::*
-namespace, which is currently left as an excercise for the reader.
+namespace, which is currently left as an exercise for the reader.
=head2 Schema versioning
__PACKAGE__->storage->sql_maker->quote_char('"');
-is enough. If the left qoute differs form the right quote, the first
+is enough. If the left quote differs form the right quote, the first
notation should be used. name_sep needs to be set to allow the
SQL generator to put the quotes the correct place.