-- 1, 注意SQL 语句开始处不要空格 -- 2, 在使用 [--] 进行注释时,后面请加空格 USE `test`; -- lastUpdateTime drop procedure if exists schema_change; delimiter ';;'; create procedure schema_change() begin if exists (select * from information_schema.columns where table_name = 't_my_table' and column_name = 'lastUpdateTime') then alter table t_my_table drop column lastUpdateTime; end if; alter table t_my_table add column lastUpdateTime datetime DEFAULT NULL; end;; delimiter ';'; call schema_change(); -- myScore drop procedure if exists schema_change; delimiter ';;'; create procedure schema_change() begin if exists (select * from information_schema.columns where table_name = 't_my_table' and column_name = 'myScore') then alter table t_my_table drop column myScore; end if; alter table t_my_table add column myScore int(11) DEFAULT '0'; end;; delimiter ';'; call schema_change(); drop procedure if exists schema_change;