SYNOPSIS

  $sqla->plugin('+BangOverrides');
  ...
  profit();

register_extensions

This allows for passing data through existing systems that attempt to have their own handling for thing but whose capabilities are now superceded by SQL::Abstract, and is primarily useful to provide access to experimental feature bundles such as SQL::Abstract::Plugin::ExtraClauses.

As an example of such a thing, given an appropriate DBIC setup (see "examples/bangdbic.pl"):

  $s->storage->sqlmaker->plugin('+ExtraClauses')->plugin('+BangOverrides');

  my $rs2 = $s->resultset('Foo')->search({
    -op => [ '=', { -ident => 'outer.y' }, { -ident => 'me.x' } ]
  });
  # (SELECT me.x, me.y, me.z FROM foo me WHERE ( outer.y = me.x ))

  my $rs3 = $rs2->search({}, {
    '!from' => sub { my ($sqla, $from) = @_;
      my $base = $sqla->expand_expr({ -old_from => $from });
      return [ $base, -join => [ 'wub', on => [ 'me.z' => 'wub.z' ] ] ];
    }
  });
  # (SELECT me.x, me.y, me.z FROM foo me JOIN wub ON me.z = wub.z WHERE ( outer.y = me.x ))

  my $rs4 = $rs3->search({}, {
    '!with' => [ [ qw(wub x y z) ], $s->resultset('Bar')->as_query ],
  });
  # (WITH wub(x, y, z) AS (SELECT me.a, me.b, me.c FROM bar me) SELECT me.x, me.y, me.z FROM foo me JOIN wub ON me.z = wub.z WHERE ( outer.y = me.x ))

  my $rs5 = $rs->search({}, { select => [ { -coalesce => [ { -ident => 'x' }, { -value => 7 } ] } ] });
  # (SELECT -COALESCE( -IDENT( x ), -VALUE( 7 ) ) FROM foo me WHERE ( z = ? ))

  my $rs6 = $rs->search({}, { '!select' => [ { -coalesce => [ { -ident => 'x' }, { -value => 7 } ] } ] });
  # (SELECT COALESCE(x, ?) FROM foo me WHERE ( z = ? ))