| CREATE TRIGGER Category_Delete ON Categories FOR DELETE AS UPDATE P SET Discontinued = 1 FROM Products AS P INNER JOIN deleted AS d ON P.CategoryID = d.CategoryID
UPDATE触发器的工作过程可将UPDATE语句看成两步操作:即捕获数据前像(before image)的DELETE语句,和捕获数据后像(after image)的INSERT语句。当在定义有触发器的表上执行UPDATE语句时,原始行(前像)被移入到deleted表,更新行(后像)被移入到inserted表。
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