使用IF语句更新字段的T-SQL动态更改字段

Question

我们有一个面额表，它存储每个唯一标识符关键字和每个面额的记录，因此任何给定的唯一标识符关键字最多可以有13行，用于指示面额达到该行内有7种不同的交易类型。我可以轻松地复制和粘贴下面的查询（这很好用）7次，每次都使用不同的SET和WHERE子句组合，但这看起来很乱，很长。

查询：

UPDATE #RecycleCashDenomsClone 
    SET startBal = 
     CASE 
      WHEN B.DenomType = '1.00' THEN A.d_01 
      WHEN B.DenomType = '2.00' THEN A.d_02 
      WHEN B.DenomType = '5.00' THEN A.d_05 
      WHEN B.DenomType = '10.00' THEN A.d_10 
      WHEN B.DenomType = '20.00' THEN A.d_20 
      WHEN B.DenomType = '50.00' THEN A.d_50 
      WHEN B.DenomType = '100.00' THEN A.d_100 
      WHEN B.DenomType = 'C0.01' THEN A.c_01 
      WHEN B.DenomType = 'C0.05' THEN A.c_05 
      WHEN B.DenomType = 'C0.10' THEN A.c_10 
      WHEN B.DenomType = 'C0.25' THEN A.c_25 
      WHEN B.DenomType = 'C0.50' THEN A.c_50 
      WHEN B.DenomType = 'C1.00' THEN A.c_100 
     END 
    FROM #VaultTotals A INNER JOIN #RecycleCashDenomsClone B ON A.importKey = B.importKey 
    WHERE A.identifier = 'D0510' 

我会喜欢做...设置if语句改变@updatedField和@whereField（VARCHAR处理），以7点不同的组合，并将其传递到查询，如下所示：

UPDATE #RecycleCashDenomsClone 
    SET @updatedField = 
     CASE 
      WHEN B.DenomType = '1.00' THEN A.d_01 
      WHEN B.DenomType = '2.00' THEN A.d_02 
      WHEN B.DenomType = '5.00' THEN A.d_05 
      WHEN B.DenomType = '10.00' THEN A.d_10 
      WHEN B.DenomType = '20.00' THEN A.d_20 
      WHEN B.DenomType = '50.00' THEN A.d_50 
      WHEN B.DenomType = '100.00' THEN A.d_100 
      WHEN B.DenomType = 'C0.01' THEN A.c_01 
      WHEN B.DenomType = 'C0.05' THEN A.c_05 
      WHEN B.DenomType = 'C0.10' THEN A.c_10 
      WHEN B.DenomType = 'C0.25' THEN A.c_25 
      WHEN B.DenomType = 'C0.50' THEN A.c_50 
      WHEN B.DenomType = 'C1.00' THEN A.c_100 
     END 
    FROM #VaultTotals A INNER JOIN #RecycleCashDenomsClone B ON A.importKey = B.importKey 
    WHERE A.identifier = @whereField  

不幸的是，这不起作用，没有错误信息，它只是不更新​​字段。如果可能的话，我想避免使用动态SQL，并且像上面提到的那样，我想避免使用不同的字段和where子句将此查询复制粘贴7次。

P.S.我测试了这两个变量varchar（10）并将它们设置为字符串。 ex./

DECLARE @updatedField VARCHAR(10) = 'startBal' 
DECLARE @whereField VARCHAR(10) = 'D0510' 

Answer 1

这不是一个解决方案，而是一个想法来帮助你。

我不喜欢这个解决方案，因为大小写在所有情况下都是相同的，并且每次都更新所有字段。

UPDATE B 
    SET startBal = CASE WHEN @updatedField = 'startBal' THEN 
       CASE 
        WHEN B.DenomType = '1.00' THEN A.d_01 
        WHEN B.DenomType = '2.00' THEN A.d_02 
        WHEN B.DenomType = '5.00' THEN A.d_05 
        WHEN B.DenomType = '10.00' THEN A.d_10 
        WHEN B.DenomType = '20.00' THEN A.d_20 
        WHEN B.DenomType = '50.00' THEN A.d_50 
        WHEN B.DenomType = '100.00' THEN A.d_100 
        WHEN B.DenomType = 'C0.01' THEN A.c_01 
        WHEN B.DenomType = 'C0.05' THEN A.c_05 
        WHEN B.DenomType = 'C0.10' THEN A.c_10 
        WHEN B.DenomType = 'C0.25' THEN A.c_25 
        WHEN B.DenomType = 'C0.50' THEN A.c_50 
        WHEN B.DenomType = 'C1.00' THEN A.c_100 
       END 
      ELSE startBal END 
      ,startBal1 = CASE WHEN @updatedField = 'startBal1' THEN 
       CASE 
        WHEN B.DenomType = '1.00' THEN A.d_01 
        WHEN B.DenomType = '2.00' THEN A.d_02 
        WHEN B.DenomType = '5.00' THEN A.d_05 
        WHEN B.DenomType = '10.00' THEN A.d_10 
        WHEN B.DenomType = '20.00' THEN A.d_20 
        WHEN B.DenomType = '50.00' THEN A.d_50 
        WHEN B.DenomType = '100.00' THEN A.d_100 
        WHEN B.DenomType = 'C0.01' THEN A.c_01 
        WHEN B.DenomType = 'C0.05' THEN A.c_05 
        WHEN B.DenomType = 'C0.10' THEN A.c_10 
        WHEN B.DenomType = 'C0.25' THEN A.c_25 
        WHEN B.DenomType = 'C0.50' THEN A.c_50 
        WHEN B.DenomType = 'C1.00' THEN A.c_100 
       END 
      ELSE startBal1 END 
    FROM #VaultTotals A INNER JOIN #RecycleCashDenomsClone B ON A.importKey = B.importKey 
    WHERE A.identifier = @whereField