$schema->resultset('foo')->search_literal('EXCEPT SELECT * FROM bar')

##</code><code>##

SELECT * FROM foo WHERE ( EXCEPT SELECT * FROM BAR )

##</code><code>##

$schema->resultset('items')->search({'mapping.container_id' => 1}, {join => 'mapping'});

##</code><code>##

SELECT * FROM items LEFT JOIN mapping ON (items.item_id = mapping.item_id) WHERE mapping.container_id = 1

##</code><code>##

SELECT items.item_id FROM items LEFT JOIN mapping ON (items.item_id = mapping.item_id) 
  EXCEPT SELECT items.item_id FROM items LEFT JOIN mapping ON (items.item_id = mapping.item_id) WHERE mapping.container_id = 1