将 MERGE 语句的执行结果插入到另一个表中

作者: 模棱22124902
来源: 51数据库
2022-08-17

USE AdventureWorks2012;
GO
CREATE TABLE Production.UpdatedInventory
    (ProductID INT NOT NULL, LocationID int, NewQty int, PreviousQty int,
     CONSTRAINT PK_Inventory PRIMARY KEY CLUSTERED (ProductID, LocationID));
GO
INSERT INTO Production.UpdatedInventory
SELECT ProductID, LocationID, NewQty, PreviousQty 
FROM
(    MERGE Production.ProductInventory AS pi
     USING (SELECT ProductID, SUM(OrderQty) 
            FROM Sales.SalesOrderDetail AS sod
            JOIN Sales.SalesOrderHeader AS soh
            ON sod.SalesOrderID = soh.SalesOrderID
            AND soh.OrderDate BETWEEN '20030701' AND '20030731'
            GROUP BY ProductID) AS src (ProductID, OrderQty)
     ON pi.ProductID = src.ProductID
    WHEN MATCHED AND pi.Quantity - src.OrderQty >= 0 
        THEN UPDATE SET pi.Quantity = pi.Quantity - src.OrderQty
    WHEN MATCHED AND pi.Quantity - src.OrderQty <= 0 
        THEN DELETE
    OUTPUT $action, Inserted.ProductID, Inserted.LocationID, Inserted.Quantity AS NewQty, Deleted.Quantity AS PreviousQty)
 AS Changes (Action, ProductID, LocationID, NewQty, PreviousQty) WHERE Action = 'UPDATE';
GO

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