Question

In our MySQL database, I have a third_party_accounts table and it has_many third_party_campaigns. However, not all accounts will have campaigns. What I would like to do in DBIx::Class is select only those accounts which have one or more campaigns. The simplest was I’ve found is as follows:

my $third_party_account_rs = $schema->resultset('ThirdPartyAccount');
my $with_campaigns_rs      = $third_party_account_rs->search(
    { third_party_account_id => \'IS NOT NULL' },
    {
        join     => 'third_party_campaigns',
        group_by => 'me.id',                                                                                                                                 
    }
);

For the relevant database columns:

mysql> select id from third_party_accounts;
+----+
| id |
+----+
|  1 |
|  2 |
|  3 |
+----+
3 rows in set (0.00 sec)

mysql> select id, third_party_account_id from third_party_campaigns;
+----+------------------------+
| id | third_party_account_id |
+----+------------------------+
|  1 |                      1 |
|  2 |                      2 |
|  3 |                      1 |
+----+------------------------+
3 rows in set (0.00 sec)

This seems like such an obvious use case that I’m sure there’s a simple way to do this, but I can’t find it.

Answer 1

my $with_campaigns_rs = 
    $schema->resultset('ThirdPartyCampaigns')
    ->search_related('third_party_account');