本文介紹了將執行 UPDATE 的 CURSOR 轉換為 CTE的處理方法，對大家解決問題具有一定的參考價值，需要的朋友們下面隨著小編來一起學習吧！
問題描述
我熟悉 CURSOR，但沒有 CTE 的經驗，也從未真正使用過它們，但我被告知它們是比 CURSOR 更好的選擇
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
為了嘗試理解 CTE 的邏輯，我編寫了以下 CURSOR，我希望將其轉換為 CTE.有人可以幫我嗎?
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
推薦答案
我會用下面的命令
UPDATE CustomerOrderStatus
SET Shipped = 1
WHERE CustomerID IN
(
SELECT CustomerID FROM OrdersProcessed
)
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