mysql可重复执行新增字段，修改字段脚本

DROP PROCEDURE IF EXISTS add_tb_column;
DELIMITER $$
CREATE PROCEDURE add_tb_column()
    BEGIN
		DECLARE  CurrentDatabase VARCHAR(100);
		SELECT DATABASE() INTO CurrentDatabase;
        IF NOT EXISTS (SELECT 1 FROM information_schema.COLUMNS  WHERE   TABLE_SCHEMA=CurrentDatabase             
            AND TABLE_NAME='T_ICP_EVENT_INFO' 
            AND COLUMN_NAME='REPT_ORG_ID' )
		THEN
          ALTER TABLE T_ICP_EVENT_INFO ADD COLUMN REPT_ORG_ID VARCHAR(32) DEFAULT NULL COMMENT '单位ID';
        END IF;
		IF EXISTS (SELECT 1 FROM information_schema.COLUMNS  WHERE   TABLE_SCHEMA=CurrentDatabase             
            AND TABLE_NAME='T_ICP_EVENT_INFO' 
            AND COLUMN_NAME='REPT_ORG_ID' )
		THEN
          ALTER TABLE T_ICP_EVENT_INFO 
		  CHANGE `REPT_ORG_ID` `REPT_ORG_ID` VARCHAR(32)  COMMENT '单位ID';
        END IF;
  END
$$ 
DELIMITER ;
CALL add_tb_column;
DROP PROCEDURE add_tb_column;