/** {@inheritdoc} */ protected function generateFilterConditionSQL(ClassMetadata $targetEntity, $targetTableAlias) { // Ensure that the filters are applied to the root entity of the inheritance tree $targetEntity = $this->_em->getClassMetadata($targetEntity->rootEntityName); // we dont care about the $targetTableAlias, in a STI there is only one table. return parent::generateFilterConditionSQL($targetEntity, $targetTableAlias); }