---
name: "DBIx::Class::SQLMaker::Role::SQLA2Passthrough"
section: "3pm"
platform: "linux"
package: "libsql-abstract-perl"
version: "2.000001-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/DBIx::Class::SQLMaker::Role::SQLA2Passthrough"
---

# DBIx::Class::SQLMaker::Role::SQLA2Passthrough(3pm)

A test of future possibilities

## NAME

DBIx::Class::SQLMaker::Role::SQLA2Passthrough - A test of future possibilities

## SYNOPSIS

- •

  select and group\_by options are processed using the richer SQLA2 code

- •

  expand\_join\_condition is provided to more easily express rich joins

See `"examples/sqla2passthrough.pl"` for a small amount of running code.

## SETUP

```
  (on_connect_call => sub {
     my ($storage) = @_;
     $storage->sql_maker
             ->with::roles('DBIx::Class::SQLMaker::Role::SQLA2Passthrough');
  })
```

### expand\_join\_condition

```
  __PACKAGE__->has_many(minions => 'Blah::Person' => sub {
    my ($args) = @_;
    $args->{self_resultsource}
         ->schema->storage->sql_maker
         ->expand_join_condition(
             $args
           );
  });
```

### on

```
  __PACKAGE__->has_many(minions => 'Blah::Person' => on {
    { 'self.group_id' => 'foreign.group_id',
      'self.rank' => { '>', 'foreign.rank' } }
  });
```

Or with ParameterizedJoinHack,

```
  __PACKAGE__->parameterized_has_many(
      priority_tasks => 'MySchema::Result::Task',
      [['min_priority'] => sub {
          my $args = shift;
          return +{
              "$args->{foreign_alias}.owner_id" => {
                  -ident => "$args->{self_alias}.id",
              },
              "$args->{foreign_alias}.priority" => {
                  '>=' => $_{min_priority},
              },
          };
      }],
  );
```

becomes

```
  __PACKAGE__->parameterized_has_many(
      priority_tasks => 'MySchema::Result::Task',
      [['min_priority'] => on {
        { 'foreign.owner_id' => 'self.id',
          'foreign.priority' => { '>=', { -value => $_{min_priority} } } }
      }]
  );
```

Note that foreign/self can appear in such a condition on either side, BUT if you want DBIx::Class to be able to use a join-less version you must ensure that the LHS is all foreign columns, i.e.

```
  on {
    +{
      'foreign.x' => 'self.x',
      'self.y' => { -between => [ 'foreign.y1', 'foreign.y2' ] }
    }
  }
```

is completely valid but DBIC will insist on doing a JOIN even if you have a fully populated row object to call `"search_related"` on - to avoid the spurious JOIN, you must specify it with explicit LHS foreign cols as:

```
  on {
    +{
      'foreign.x' => 'self.x',
      'foreign.y1' => { '<=', 'self.y' },
      'foreign.y2' => { '>=', 'self.y' },
    }
  }
```