mysql函数

DELIMITER $$ DROP FUNCTION IF EXISTS `func_check_db_exists`$$ CREATE FUNCTION `func_check_db_exists`(db_name varchar(64)) RETURNS varchar(20) CHARSET utf8BEGIN  if exists(select 1 from information_schema.schemata where schema_name=db_name) then    return 'Exists!';  else    return 'Not exists!';  end if;END$$ DELIMITER ;