sql-server - 更新 SQL Server 中的 Select Case 语句：

Question

我编写了以下更新语句来更新 PLN_DU_Vendor 表的 StatusID。

UPDATE 
PLN_DU_Vendor
SET
    PLN_DU_Vendor.StatusID = 2
FROM
    PLN_DU_Vendor 
INNER JOIN PMT_RFDDetail D ON PLN_DU_Vendor.DUID = D.DUID
INNER JOIN PMT_RFDHeader H ON H.RFDID = D.RFDID AND PLN_DU_Vendor.VendorID = H.VendorID
INNER JOIN PLN_LASCO_Header LH ON LH.LASCOID = H.LASCOID AND LH.ReleaseID = PLN_DU_Vendor.ReleaseID
AND PLN_DU_Vendor.VendorDUQuantity = (D.DespatchQuantity + ISNULL(PLN_DU_Vendor.RFDQuantity, 0))
WHERE
     H.RFDID = 10

如果条件

PLN_DU_Vendor.VendorDUQuantity = (D.DespatchQuantity + ISNULL(PLN_DU_Vendor.RFDQuantity, 0))

失败，我需要将 StatusID 更新为 1。如何在同一更新选择语句中执行此操作。

Answer 1

看起来您希望将条件从 移动JOIN到分配作为CASE语句：

UPDATE 
PLN_DU_Vendor
SET
    PLN_DU_Vendor.StatusID = CASE 
    WHEN PLN_DU_Vendor.VendorDUQuantity = (D.DespatchQuantity + ISNULL(PLN_DU_Vendor.RFDQuantity, 0))
    THEN 2
    ELSE 1
    END
FROM
    PLN_DU_Vendor 
INNER JOIN PMT_RFDDetail D ON PLN_DU_Vendor.DUID = D.DUID
INNER JOIN PMT_RFDHeader H ON H.RFDID = D.RFDID AND PLN_DU_Vendor.VendorID = H.VendorID
INNER JOIN PLN_LASCO_Header LH ON LH.LASCOID = H.LASCOID AND LH.ReleaseID = PLN_DU_Vendor.ReleaseID
WHERE
     H.RFDID = 10

Answer 2

您无法比较任何浮点数与运算符=

PLN_DU_Vendor.VendorDUQuantity = (D.DespatchQuantity + ISNULL(PLN_DU_Vendor.RFDQuantity, 0))

所以，最好是

PLN_DU_Vendor.VendorDUQuantity - (D.DespatchQuantity + ISNULL(PLN_DU_Vendor.RFDQuantity, 0)) < ERROR