mysql 一个语法错误

业务说明，首先查询出一条数据，然后再更新着跳数据。

比如：

update user set age = (select age from user where user_name = 'tom') + 1 where user_name = 'tom';

会执行错误

You can't specify target table '表名' for update in FROM clause错误

错误原因：mysql不能同时查询并且修改同一条数据（oracle）不会有这个错

解决方法：通过建立中间表的方式，修改数据

update user set age = (select b.age from (select user_name,age from user where user_name = 'tom')b where b.user_name = 'tom') + 1 where user_name = 'tom';