SQL 2005中的嵌套选择查询

本文介绍了SQL 2005中的嵌套选择查询的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有两个桌子. 1.管理员(用户名，密码) 2.User(用户名，类型) 我已经提供了用户名和密码，我想从User表中检索用户类型.

I have two table. 1.Admin(username,password) 2.User(username,type) I have given username and password and I want retrieve the type of user from User table.

推荐答案

select type from [User] where username = 'the_username_wanted'

一个简单的连接就是你要的 a simple join is what you are after SELECT * FROM Admin a JOIN User u ON a.username = u.username WHERE a.username = @username AND a.password = @password

关于CP的连接，也有不错的文章此处 [ ^ ]

There is also a good article on CP about joins here[^]

select type from user where username = @username

@username是您必须将其传递给存储过程或sql语句的参数.

@username is a parameter that you have to pass it to stored procedure or sql statement.