两个查询在一个与SQL Server

Question

这就是我试图做类似下面的请求的东西，但我不知道是否有可能与SQL-Server语法：

declare @idClient int 

select @idClient=idClient from table 
where entite is null and (SELECT * from table where entite=@idClient) is null 

谢谢。

Answer 1

也许这样？

SELECT t1.[idClient] 
FROM [table] t1 
WHERE [entite] IS NULL 
     AND NOT EXISTS (
      SELECT NULL 
      FROM [table] t2 
      WHERE t2.[entite]=t1.[idClient] 
     )