SQL 订购时按自定义案例订购

Question

我正在尝试自定义 ORDER BY 子句，以便 'Other Companies' 始终排在最后。我不确定这里出了什么问题。这是我所有的代码。 WHERE 子句可能看起来多余，但那是因为参数被宏代码替换，其中 SQL 字符串被上传以根据日期和状态以不同方式填充。别担心。我以前在另一种情况下做过这件事，我订购了所有东西，但没有使用两个不同的列。输出表明 ORDER BY 子句中的 'AmountOfClaims' 不是有效列。有人可以帮助我吗？

SELECT 
    CASE 
       WHEN co.[CompanyName] != '' 
          THEN co.CompanyName 
          ELSE 'Unspecified Companies' 
    END AS CompanyName, 
    COUNT(co.[CompanyName]) AS [AmountOfClaims]
FROM
    (SELECT 
         CASE 
            WHEN [Claims].[CompanyName] IN (SELECT TOP 10 [Claims].[CompanyName]
                                            FROM [Claims]
                                            WHERE Claims.[HousingRequested] >= '2016-08-02'
                                              AND Claims.[HousingRequested] <= '2016-08-16'
                                              AND (Claims.[State] = NULL OR Claims.[State] >= CASE WHEN NULL IS NULL THEN ' ' ELSE 'ZZZZ' END)
                                            GROUP BY [Claims].[CompanyName]
                                            ORDER BY COUNT([Claims].[CompanyName]) DESC)
               THEN [Claims].[CompanyName] 
               ELSE 'Other Companies' 
         END AS [CompanyName]
     FROM 
         [Claims] 
     WHERE 
         Claims.[HousingRequested] >= '2016-08-02'
         AND Claims.[HousingRequested] <= '2016-08-16'
         AND (Claims.[State] = NULL OR Claims.[State] >= CASE WHEN NULL IS NULL THEN ' ' ELSE 'ZZZZ' END)
    ) AS co
GROUP BY 
    co.[CompanyName]
ORDER BY 
    CASE 
       WHEN [CompanyName] = 'Other Companies' 
          THEN 9999 
          ELSE [AmountOfClaims] 
    END DESC

Answer 1

您可以将当前查询用作派生的 table 或 CTE，或者只使用 ORDER BY:

中的 COUNT

SELECT 
    CASE WHEN co.[CompanyName] != '' THEN co.CompanyName ELSE 'Unspecified Companies' END AS CompanyName, 
    COUNT(co.[CompanyName]) AS [AmountOfClaims]
FROM
    ( SELECT CASE WHEN [Claims].[CompanyName] IN

            ( SELECT TOP 10 [Claims].[CompanyName]
            FROM [Claims]
                WHERE Claims.[HousingRequested] >= '2016-08-02'
                AND Claims.[HousingRequested] <= '2016-08-16'
                AND (Claims.[State] = NULL OR Claims.[State] >= CASE WHEN NULL IS NULL THEN ' ' ELSE 'ZZZZ' END)

            GROUP BY [Claims].[CompanyName]
            ORDER BY COUNT([Claims].[CompanyName]) DESC )

        THEN [Claims].[CompanyName] ELSE 'Other Companies' END AS [CompanyName]

    FROM [Claims] 
        WHERE Claims.[HousingRequested] >= '2016-08-02'
        AND Claims.[HousingRequested] <= '2016-08-16'
        AND (Claims.[State] = NULL OR Claims.[State] >= CASE WHEN NULL IS NULL THEN ' ' ELSE 'ZZZZ' END)
    ) AS co

GROUP BY co.[CompanyName]
ORDER BY CASE WHEN [CompanyName] = 'Other Companies' THEN 9999 ELSE COUNT(co.[CompanyName]) END DESC;

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