sql-server - SQL Server - 具有多个字段的 IN 子句

Question

是否可以在 IN 子句中包含多个字段？类似于以下内容:

select * from user
where code, userType in ( select code, userType from userType )

我使用的是 ms sql server 2008

<小时/>

我知道这可以通过连接和存在来实现，我只是想知道是否可以通过 IN 子句来完成。

Answer 1

不是您发布的方式。您只能返回单个字段或类型，IN 才能正常工作。

来自 MSDN (IN):

test_expression [ NOT ] IN 
    ( subquery | expression [ ,...n ]
    ) 

subquery - Is a subquery that has a result set of one column. 
           This column must have the same data type as test_expression.

expression[ ,... n ] - Is a list of expressions to test for a match. 
                       All expressions must be of the same type as 
                       test_expression.

您可以使用以下两个字段来使用 JOIN，而不是 IN:

SELECT U.* 
FROM user U
  INNER JOIN userType UT
    ON U.code = UT.code
    AND U.userType = UT.userType