SQL Server Select语句与count。

I'm writing a query to determine if a user is an administrator on my website or not.

我正在编写一个查询来确定用户是否是我网站上的管理员。

I can't quite figure out how to display "True" or "False" after my initial select.

在我最初的选择之后，我不知道如何显示“True”或“False”。

select count(*) as IsAdmin 
from UserRoles 
where UserID = '1' and RoleID = 1

IF count is != 0 => True
ELSE False

My IF is also not working, probably because I'm writing something incorrectly. RoleID=1 means they are administrators.

我的IF也不起作用，可能是因为我写错了东西。RoleID=1表示他们是管理员。

2 个解决方案

#1

Use exists in your IF and then proceed with your logic / what you want to return

使用存在于IF中，然后继续您的逻辑/您想要返回的内容

IF(exists(select 1 as IsAdmin from UserRoles where UserID='1' and RoleID = 1))
   SELECT 'IS ADMIN'
ELSE
   SELECT 'IS NOT ADMIN'

If in another scenario you were trying to check for a certain number, you can use it as such:

如果在另一个场景中，您试图检查某个数字，您可以这样使用:

IF(select count(*) as IsAdmin from UserRoles where UserID='1' and RoleID = 1) > 0
   SELECT 'IS ADMIN'
ELSE
   SELECT 'IS NOT ADMIN'

#2

select (case when UserID = '1' and RoleID = 1 then 1 else 0 end) as IsAdmin
from UserRoles