本文介绍了将执行 UPDATE 的 CURSOR 转换为 CTE的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我熟悉 CURSOR，但没有 CTE 的经验，也从未真正使用过它们，但我被告知它们是比 CURSOR 更好的选择
I am familiar with CURSORS, but have no experience of CTE's and have never really used them but have been advised that they are a better option than CURSOR's
为了尝试理解 CTE 的逻辑，我编写了以下 CURSOR，我希望将其转换为 CTE.有人可以帮我吗?
To try and understand the logic of CTE's, I have written the following CURSOR which I hope to convert to a CTE. Can somebody help me?
DECLARE @CustomerID UNIQUEIDENTIFIER
DECLARE SalesOrderCursor CURSOR READ_ONLY
FOR
SELECT CustomerID FROM OrdersProcessed
OPEN SalesOrderCursor
FETCH NEXT FROM SalesOrderCursor INTO @CustomerID
WHILE @@FETCH_STATUS = 0
BEGIN
UPDATE CustomerOrderStatus SET Shipped = 1 WHERE CustomerID = @CustomerID
END
FETCH NEXT FROM SalesOrderCursor INTO @CustomerID
END
推荐答案
我会用下面的命令
UPDATE CustomerOrderStatus
SET Shipped = 1
WHERE CustomerID IN
(
SELECT CustomerID FROM OrdersProcessed
)
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