相关疑难解决方法(0)

我将使用一个具体的,但假设的例子.

每个订单通常只有一个订单项:

命令:

OrderGUID   OrderNumber
=========   ============
{FFB2...}   STL-7442-1      
{3EC6...}   MPT-9931-8A

了LineItem:

LineItemGUID   Order ID Quantity   Description
============   ======== ========   =================================
{098FBE3...}   1        7          prefabulated amulite
{1609B09...}   2        32         spurving bearing

但偶尔会有一个包含两个订单项的订单:

LineItemID   Order ID    Quantity   Description
==========   ========    ========   =================================
{A58A1...}   6,784,329   5          pentametric fan
{0E9BC...}   6,784,329   5          differential girdlespring 

通常在向用户显示订单时:

SELECT Orders.OrderNumber, LineItems.Quantity, LineItems.Description
FROM Orders
    INNER JOIN LineItems 
    ON Orders.OrderID = LineItems.OrderID

我想在订单上显示单个项目.但是,由于此偶尔包含两个(或更多)商品的订单,订单将显示为重复:

OrderNumber   Quantity   Description
===========   ========   ==================== …