.sql文件查询使用变量

Question

我想像这样执行多个查询

Delete FROM TableA where CreatedBy="2"
Delete FROM TableB where CreatedBy="2"
Delete FROM TableC where CreatedBy="2"
Delete FROM TableD where CreatedBy="2"

我还想使用该id进行更多更新和插入查询。即使ID可能会发生变化 每次我必须改变价值来做到这一点 有没有办法声明变量并执行quires 例如

var userid=2;
Delete FROM TableA where CreatedBy="userid"
Delete FROM TableB where CreatedBy="userid"
Delete FROM TableC where CreatedBy="userid"
Delete FROM TableD where CreatedBy="userid"

如果我只改变一个地方，那个地方的名字会随处变化 我想创建一个sql文件并将其运行到我的MySQL服务器来更改用户标识 反正有吗？怎么样？

Answer 1

您可以这样设置会话变量：

SET @userid := '2';
DELETE FROM `TableA` WHERE `CreatedBy` = @userid;
DELETE FROM `TableB` WHERE `CreatedBy` = @userid;
DELETE FROM `TableC` WHERE `CreatedBy` = @userid;
DELETE FROM `TableD` WHERE `CreatedBy` = @userid;