doctrine2/manual/docs/en/dql-doctrine-query-language/delete-queries.txt

<code type="sql">
DELETE FROM <component_name>
    [WHERE <where_condition>]
    [ORDER BY ...]
    [LIMIT <record_count>]
</code>

* The {{DELETE}} statement deletes records from {{component_name}} and returns the number of records deleted.
* The optional {{WHERE}} clause specifies the conditions that identify which records to delete. Without {{WHERE}} clause, all records are deleted.
* If the {{ORDER BY}} clause is specified, the records are deleted in the order that is specified.
* The {{LIMIT}} clause places a limit on the number of rows that can be deleted. The statement will stop as soon as it has deleted {{record_count}} records.

<code type="php">
$q    = 'DELETE FROM Account WHERE id > ?';

$rows = $this->conn->query($q, array(3));

// the same query using the query interface

$q = new Doctrine_Query();

$rows = $q->delete('Account')
          ->from('Account a')
          ->where('a.id > ?', 3)
          ->execute();

print $rows; // the number of affected rows
</code>