设置变量时的SQL情况

Question

我试图在块

的情况下设置2声明变量

这是我的代码：

DECLARE @like bit,@dislike bit
if exists
( select * 
    ,@like = (CASE WHEN likeordislike = 1 THEN 'true' ELSE 'false' END)
    ,@dislike=(CASE WHEN likeordislike = 0 THEN 'true' ELSE 'false' END)
  from likeordislike
)

但是当我执行查询抛出错误时：

  

Msg 102，Level 15，State 1，Line 4
  '='附近的语法不正确。

一切都好吗？无法理解

Answer 1

if (select count(*) from likeordislike where user = @user and comment_id = @comment_id) = 0
begin
  insert into likeordislike etc
end 
else
  update likeordislike etc
end