Question

我想做以下事情。

SELECT aspnet_Users.UserName, aspnet_Membership.Email, count(*) as Activities
FROM aspnet_Users
     INNER JOIN Activities ON aspnet_Users.UserId = Activities.ActUserID
     INNER JOIN aspnet_Membership ON aspnet_Users.UserId = aspnet_Membership.UserId
     WHERE Activities.ActDateTime >= GETDATE()
     GROUP BY aspnet_Users.UserName
     ORDER BY Activities DESC

但这给了我一个错误。

列'aspnet_Membership.Email'在选择列表中无效，因为它不包含在聚合函数或GROUP BY子句中。

我有点理解错误。我正在尝试选择不属于分组的列。

但是，aspnet_Membership.Email和aspnet_Users.UserId之间始终存在一对一的关系。那么我该如何实现呢？

Answer 1

变化：

GROUP BY aspnet_Users.UserId

要：

GROUP BY aspnet_Users.UserName, aspnet_Membership.Email

如果您不想退回，或者您认为不应该按想要的列分组，为什么您认为您需要在分组中提及UserId列？回来。

Answer 2

要选择一个列，它必须是group by子句或聚合，你可以考虑分组（aspnet_Users.UserName，aspnet_Membership.Email，aspnet_Users.UserId）。

我的猜测是可行的

获取与GROUP BY列相关的列

2 个答案: