sql-server - 在 SUM 字段上使用 HAVING 或 WHERE

Question

问题

我们有一个 Users 表和一个 Addresses 表。每个用户可以有多个地址。我们有一个名为 IsDefault 的位字段，用户可以在其中选择他们的默认地址。这个字段目前不是强制性的，将来可能会是，所以我需要做一些分析。现在我想验证地址以查看:

• 给定用户有多少个地址。
• 这些地址中有多少(如果它们有多个地址)IsDefault 标志设置为 1。

基本上，我想了解有多少拥有多个地址的用户没有打开他们的任何地址作为默认地址。

到目前为止，我有以下 SQL 查询:

SELECT  AD.User_Id,
        COUNT(AD.User_Id) AS HowManyAddresses,
        SUM(
            CASE WHEN 
                AD.IsDefault IS NULL 
                OR
                AD.IsDefault = 0
            THEN
                1
            ELSE
                0
            END
        ) AS DefaultEmpty,

        SUM(
            CASE WHEN 
                AD.IsDefault = 1
            THEN
                1
            ELSE
                0
            END
        ) AS DefaultAddress

FROM dbo.Addresses AS AD
    JOIN dbo.Users AS U
    ON U.Id = AD.User_Id
GROUP BY AD.User_ID
ORDER BY AD.User_Id

我发现的问题是我想检查 DefaultAddress 和 DefaultEmpty SELECT SUM 字段中的值，但是在尝试使用以下方法引用它们时出现以下错误哪里或拥有:

Invalid column name 'DefaultEmpty'.

是否无法引用 SUM 值进行选择？

使用的技术:

1. SQL Server 2008
2. SQL Server 管理工作室 2008

Answer 1

实际上你需要像这样用 HAVING 重复整个 SUM 子句 -

SELECT
    AD.User_Id
    ,COUNT(AD.User_Id) AS HowManyAddresses
    ,SUM(
    CASE
        WHEN
            AD.IsDefault IS NULL OR
            AD.IsDefault = 0 THEN 1
        ELSE 0
    END
    ) AS DefaultEmpty
    ,SUM(
    CASE
        WHEN
            AD.IsDefault = 1 THEN 1
        ELSE 0
    END
    ) AS DefaultAddress

FROM dbo.Addresses AS AD
JOIN dbo.Users AS U
    ON U.Id = AD.User_Id
GROUP BY AD.User_ID
HAVING SUM(
CASE
    WHEN
        AD.IsDefault IS NULL OR
        AD.IsDefault = 0 THEN 1
    ELSE 0
END
) = 0
ORDER BY AD.User_Id

或

DECLARE @address TABLE(UserID INT,Address VARCHAR(100),IsDefault BIT);
INSERT INTO @address VALUES
 (1,'User 1 default',1)
,(2,'User 2 non default',0)
,(3,'User 3 non default',0)
,(3,'User 3 default',1)
,(4,'User 4 default',1)
,(4,'User 4 second default',1);

SELECT
    COUNT(*) OVER () AS HowManyAddresses
    ,ISNULL(def0.DefaultEmpty, 0) AS DefaultEmpty
    ,ISNULL(def1.DefaultAddress, 0) AS DefaultAddress
FROM (SELECT
        AD.Address
        ,COUNT(AD.UserID) OVER (PARTITION BY AD.UserID) AS DefaultEmpty
    FROM @address AS AD
    WHERE (AD.IsDefault = 0)) def0
FULL JOIN (SELECT
        AD.Address
        ,COUNT(AD.UserID) OVER (PARTITION BY AD.UserID) AS DefaultAddress
    FROM @address AS AD
    WHERE (AD.IsDefault = 1)) def1
    ON def0.Address = def1.Address