Question

有人愿意指出我正确的方向吗？我正在使用AdventureWorks2012数据库来完成一些培训，我不太清楚如何解决我需要找到所有不使用“OVERSEAS -DELUXE”或“过夜”运输方式的采购订单（SalesOrderHeader）的问题J-FAST“（ShipMethod）和我必须使用公用表表达式。

这是我到目前为止所提出的，这似乎是不正确的：

 WITH filteredshipmethods (ShipMethodID, Name, PurchaseOrderNumber)
    as 
    (SELECT Purchasing.PurchaseOrderHeader.ShipMethodID, Purchasing.ShipMethod.Name, Sales.SalesOrderHeader.PurchaseOrderNumber
FROM     Purchasing.PurchaseOrderHeader INNER JOIN
                  Purchasing.ShipMethod ON Purchasing.PurchaseOrderHeader.ShipMethodID = Purchasing.ShipMethod.ShipMethodID INNER JOIN
                  Sales.SalesOrderHeader ON Purchasing.ShipMethod.ShipMethodID = Sales.SalesOrderHeader.ShipMethodID
WHERE   Purchasing.ShipMethod.Name <> 'OVERSEAS - DELUXE' AND Purchasing.ShipMethod.Name <> 'OVERNIGHT J-FAST' And PurchaseOrderNumber is not null)
    SELECT PurchaseOrderNumber, ShipMethodID, Name
    From filteredshipmethods
    Group By ShipMethodID, Name, PurchaseOrderNumber
    Order By Name;

Answer 1

如果任务只是找到SalesOrderHeaders，那你为什么要加入PurchaseOrderHeader？并且请使用别名，它将帮助您最小化代码并更好地理解您拥有的内容。

WITH    filteredshipmethods
          AS ( SELECT   soh.PurchaseOrderNumber ,
                        sm.ShipMethodID ,
                        sm.Name
               FROM     Sales.SalesOrderHeader soh
                        INNER JOIN Purchasing.ShipMethod sm ON soh.ShipMethodID = sm.ShipMethodID
               WHERE    sm.Name <> 'OVERSEAS - DELUXE'
                        AND sm.Name <> 'OVERNIGHT J-FAST'
             )
    SELECT  PurchaseOrderNumber ,
            ShipMethodID ,
            Name
    FROM    filteredshipmethods
    GROUP BY PurchaseOrderNumber ,
            ShipMethodID ,
            Name

如何使用公用表表达式进行过滤

1 个答案: