-- Licensed to the Apache Software Foundation (ASF) under one or more
-- contributor license agreements.  See the NOTICE file distributed with
-- this work for additional information regarding copyright ownership.
-- The ASF licenses this file to You under the Apache License, Version 2.0
-- (the "License"); you may not use this file except in compliance with
-- the License.  You may obtain a copy of the License at
--
--     http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.

DECLARE
	v_column_exists number := 0;
BEGIN
  Select count(*) into v_column_exists
    from user_tab_cols
    where column_name = upper('owned_by')
      and table_name = upper('x_tag');

  if (v_column_exists = 0) then
      execute immediate 'ALTER TABLE x_tag ADD owned_by NUMBER(6) DEFAULT 0 NOT NULL';
      commit;
  end if;
end;/