带有case语句的SQL where子句

本文介绍了带有case语句的SQL where子句的处理方法，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

我有一个SQL问题，但尚未找到解决方案，我要尝试做的是在过程中使用where子句，其中userID变量可以包含有效的userID或-1来指示所有用户./p>

但是我仍然停留在where子句的这一部分:

AND usertable.userid = CASE WHEN @user = -1 THEN ELSE @user END

我不确定如何处理-1以说选择所有用户

谢谢

解决方案

以下方法可能会起作用:

SELECT whatever FROM wherever WHERE something = somethingelse AND usertable.userid = CASE @user WHEN -1 THEN usertable.userid ELSE @user END

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I have a problem with SQL that I have not yet found a solution to, what im trying to do is a where clause for a procedure where a userID variable can contain either a valid userID or -1 to indicate all users.

However im stuck at this part of the where clause:

AND usertable.userid = CASE WHEN @user = -1 THEN ELSE @user END

I'm not sure how to process the -1 to say select all users

Thanks

解决方案

Perhaps the following would work:

SELECT whatever FROM wherever WHERE something = somethingelse AND usertable.userid = CASE @user WHEN -1 THEN usertable.userid ELSE @user END

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