关于微软有自增列父子表更新程序的问题

最新推荐文章于 2023-12-18 18:55:34 发布

转载最新推荐文章于 2023-12-18 18:55:34 发布 · 70 阅读

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原文链接：http://www.cnblogs.com/tonyepaper/archive/2009/10/22/1587764.html

本文探讨了在.NET框架中处理SQLRowUpdatedEventArgs时的具体细节，特别是如何使用UpdateStatus.SkipCurrentRow来阻止某些更改，并解释了为何在设置SkipCurrentRow之后还需要调用AcceptChanges()方法。

有一些不明白它的意思.请高手详细说明一下原由.谢谢!
来源网址:http://support.microsoft.com/?scid=kb%3Bzh-cn%3B320301&x=11&y=15

         protected static void OnDetailsRowUpdated( object sender, SqlRowUpdatedEventArgs args)
        {
             if (args.StatementType == StatementType.Insert )
            {
                 // Do not allow the AcceptChanges to occur on this row.
                args.Status = UpdateStatus.SkipCurrentRow; // 这里为什么要用UpdateStatus.SkipCurrentRow

                 // Get the current, actual primary key value so that you can plug it back
                 // in after you get the correct original value that was generated for the child row.
                 int currentkey = ( int )args.Row[ " OrderID " ];
                 // This is where you get a correct original value key that is stored to the child row.
                 // You pull the original, pseudo key value from the parent, plug it in as the child row's primary key
                 // field, and then accept changes on it. Specifically, this is why you turned off EnforceConstraints.
                args.Row[ " OrderID " ] = args.Row.GetParentRow( " OrdDetail " )[ " OrderID " ,DataRowVersion.Original];
                args.Row.AcceptChanges(); // 上面用了UpdateStatus.SkipCurrentRow,这里为什么还要AcceptChanges(),感觉矛盾.
                 // Store the actual primary key value in the foreign key column of the child row.
                args.Row[ " OrderID " ] = currentkey; // 为什么又改回原来的值???
            }

             if (args.StatementType == StatementType.Delete )
                args.Status = UpdateStatus.SkipCurrentRow; // 这里也不明白它的用意.

转载于:https://www.cnblogs.com/tonyepaper/archive/2009/10/22/1587764.html