SQL合併聲明在存儲過程中不起作用

Question

下面的代碼似乎不起作用。如果該地址不存在，則不會插入新記錄。但是，如果地址確實存在，則確實會更新。

ALTER PROCEDURE [Users].[UpdateAddress] 
    @UserId int, 
    @Address1 varchar(100), 
    @Address2 varchar(100), 
    @Town varchar(100), 
    @County varchar(50), 
    @PostCode varchar(50), 
    @Country varchar(50), 
    @Type INT 
AS 

MERGE [Users].[Addresses] AS Target 
USING (SELECT UserId FROM [Users].[Addresses] WHERE UserId = @UserId) AS Source 
ON (Source.UserId = Target.UserId) 

WHEN MATCHED THEN 
    UPDATE SET Target.Address1 = @Address1, 
    Target.Address2 = @Address2, 
    Target.Town = @Town, 
    Target.County = @County, 
    Target.Postcode = @Postcode, 
    Target.Country = @Country 
WHEN NOT MATCHED BY TARGET THEN 
    INSERT ([UserId], [Address1], [Address2], [Town], [County], [PostCode], [Country], [Modified], [Type]) 
    VALUES(@UserId, @Address1, @Address2, @Town, @County, @PostCode, @Country, GetDate(), @Type); 

Answer 1

您的源代碼不應該依賴目標表。嘗試改爲：

MERGE [Users].[Addresses] AS Target 
USING (select @UserID,@Address1,@Address2,@Town,@County,@PostCode,@Country,@Type) 
    AS Source (UserID,Address1,Address2,Town,County,PostCode,Country,Type) 
ON (Source.UserId = Target.UserId) 
WHEN MATCHED THEN 
    UPDATE SET Target.Address1 = Source.Address1, 
    Target.Address2 = Source.Address2, 
    Target.Town = Source.Town, 
    Target.County = Source.County, 
    Target.Postcode = Source.Postcode, 
    Target.Country = Source.Country 
WHEN NOT MATCHED BY TARGET THEN 
    INSERT ([UserId], [Address1], [Address2], [Town], [County], [PostCode], [Country], [Modified], [Type]) 
    VALUES(Source.UserId, Source.Address1, Source.Address2, Source.Town, Source.County, Source.PostCode, Source.Country, GetDate(), Source.Type); 

此刻，你正在創建一個零排Source行集，所以當然沒有在合併發生。