DELETE ... OUTPUT COUNT（DELETED。*）

Question

我想知道在某個DELETE操作中刪除了多少行。

我拿了微軟的例子B

DELETE Sales.ShoppingCartItem
OUTPUT DELETED.* 
WHERE ShoppingCartID = 20621;

並嘗試修改它以僅返回已刪除記錄的count ：

DELETE FROM datacache 
OUTPUT COUNT(DELETED.*)
WHERE userId=@id

但這引發了

ExceptionMessage: "Incorrect syntax near '*'."
ExceptionType: "System.Data.SqlClient.SqlException"
Message: "Error"

所以我試過了

DELETE FROM datacache 
OUTPUT COUNT(DELETED)
WHERE userId=@id

哪個扔了

ExceptionMessage: "Invalid column name 'DELETED'."
ExceptionType: "System.Data.SqlClient.SqlException"
Message: "Error"

我錯過了什么？

Answer 1

只需運行您的查詢並獲取修改后的行

DELETE 
FROM datacache 
WHERE userId=@id

SELECT @@ROWCOUNT

Answer 2

您不能在OUTPUT子句中使用聚合。 您可以將任何列輸出到表變量中，並從那里開始計數：

DECLARE @t TABLE(id int)

DELETE FROM Sales.ShoppingCartItem
OUTPUT Deleted.ShoppingCartID INTO @t
WHERE ShoppingCartID = 20621;

SELECT COUNT(*) FROM @t

Answer 3

之后如何計算記錄？

DELETE Sales.ShoppingCartItem
OUTPUT DELETED.ID INTO @DELETEDIDS
WHERE ShoppingCartID = 20621;

SELECT COUNT(*)
FROM @DELETEDIDS;

或者，只需運行查詢並使用@@ROWCOUNT 。