CONCAT('SELECT ''sys_dept'' AS table_name, ''',column_name,''' AS column_name, ''',IFNULL(column_comment,''),''' AS column_comment, ''ALTER TABLE `sys_dept` DROP COLUMN `',column_name,'`;'' AS drop_sql FROM dual WHERE (SELECT COUNT(`',column_name,'`) FROM `sys_dept`) = 0')
CONCAT('SELECT ''sys_user'' AS table_name, ''',column_name,''' AS column_name, ''',IFNULL(column_comment,''),''' AS column_comment, ''ALTER TABLE `sys_user` DROP COLUMN `',column_name,'`;'' AS drop_sql FROM dual WHERE (SELECT COUNT(`',column_name,'`) FROM `sys_user`) = 0')