如何选择值 [英] How to select values

问题描述

Hi,

If(@username='Ram')
Begin
Select Professor,Stu_name,Location,Subject From student where Location in('Hyderabad','Banglore','Chennai')
End
Else if(@username='Krishna')
Begin
Select Professor,Stu_name,Location,Subject From student where Location in('Pune','Mumbai','Kolkata')
End

我不需要像上面那样进行硬编码. 我想要类似的逻辑，如果用户使用ram..i登录需要设置位置，如果用户使用krishna ..i登录需要设置位置...

通过使用SET，我们一次只能为一个变量设置一个值...所以当用户使用该特定用户名登录时，我需要为Location变量设置多个值..我该怎么做...

Ii don''t need to to Hard code like above..
I want logic like , if user logined with ram..i need to set Location,if user logined with krishna ..i need to set Location...

by using SET we can set only one value at a time for a variable...so i need to set multiple values for Location variable when user logined with that particular username..how can i do it...

@Declare @location varchar(20)
If(@username='Ram')
Begin
set @location='Hyderabad','Banglore','Chennai'
end
Else if(@username='krishna')
Begin
set @location='Chennai','Pune','Mumbai'
End

选择教授，学生名称，位置，来自学生的主题，其中Location = @ location


所以我想要上面的逻辑....

请帮助我

Select Professor,Stu_name,Location,Subject From student where Location=@location


So i want logic like above ....

Please Help me

推荐答案

按照您的方式进行操作或从表中查找.但是，如果您不能从表中查找它，那么您也可以执行CASE语句.

Either do it the way you are or look it up from a table. But if you can''t look it up from a table you can also do a CASE statement.

SET @location = CASE WHEN @username='Ram' THEN '1,2,3' WHEN @username='t' THEN 'x' ELSE 'z' END

但是，如果可以的话，最好的方法是查找它.

But the best thing to do is look it up, if you can.

SELECT @location = location FROM locationTable WHERE userid = @username

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