Question

早上好。我是SQL的初学者。

我想修改下面的MS-SQL过程。

我想在查询语句的中间添加一个分支语句，但这并不如我所想。

谢谢！

WITH W_TEST AS (
    SELECT T1.ID
        ,T2.NAME 
        ,T1.ADDRESS
        ,T1.NUMBER
        FROM TEST_TBL1 T1
        INNER JOIN TEST_TBL2 T2 ON T1.OBJECTID = T2.OBJECTID 
    WHERE T1.TYPE != 14 

    -- ======= This is the part you want to modify.
    IF (Condition 1)
    BEGIN
        GROUP BY T1.ID
            ,T2.NAME 
            ,T1.ADDRESS
            ,T1.NUMBER
        HAVING (
                (SELECT MAX(NEXT_NUM) AS NEXT_NUMBER
                FROM NUMBER_TBL1
                WHERE GRADE = 3
                ) < MAX(T1.NUMBER)
        )
    END

    ELSE
    BEGIN
        -- Branch statement not including grammar
    END
    -- ======= This is the part you want to modify.

  )

Answer 1

您需要创建两个单独的语句或使用动态T-SQL。既然您是新手，那么使用单独的语句将很容易使用：

 IF (Condition 1)
    BEGIN
        WITH W_TEST AS (
        SELECT T1.ID
            ,T2.NAME 
            ,T1.ADDRESS
            ,T1.NUMBER
            FROM TEST_TBL1 T1
            INNER JOIN TEST_TBL2 T2 ON T1.OBJECTID = T2.OBJECTID 
        WHERE T1.TYPE != 14 
         GROUP BY T1.ID
            ,T2.NAME 
            ,T1.ADDRESS
            ,T1.NUMBER
        HAVING (
                (SELECT MAX(NEXT_NUM) AS NEXT_NUMBER
                FROM NUMBER_TBL1
                WHERE GRADE = 3
                ) < MAX(T1.NUMBER)
        )
        ...
    END
ELSE
    BEGIN
        WITH W_TEST AS (
        SELECT T1.ID
            ,T2.NAME 
            ,T1.ADDRESS
            ,T1.NUMBER
            FROM TEST_TBL1 T1
            INNER JOIN TEST_TBL2 T2 ON T1.OBJECTID = T2.OBJECTID 
        WHERE T1.TYPE != 14 
        )
        ..
    END

Answer 2

首先，您需要准备所需的中间查询，然后通过与中间查询连接来构建最终查询。您可以从此链接中获得一些想法： Building Dynamic Query

MSSQL-添加SQL中间IF-ELSE

2 个答案: