Cake\Database\Schema\PostgresSchema::_convertOnClause PHP Method

    protected function _convertOnClause($clause)
    {
        if ($clause === 'r') {
            return Table::ACTION_RESTRICT;
        }
        if ($clause === 'a') {
            return Table::ACTION_NO_ACTION;
        }
        if ($clause === 'c') {
            return Table::ACTION_CASCADE;
        }
        return Table::ACTION_SET_NULL;
    }