防止删除特定记录

Question

我想防止删除特定记录。此触发器适用于该特定记录。但是，其他记录在被删除时仍然存在。为什么？

 ALTER TRIGGER [Globalization].[CountriesTracker] 
 ON [Globalization].[Countries] 
 INSTEAD OF DELETE
 AS 
 BEGIN
SET NOCOUNT ON;
IF ((Select COUNT(*) from [Deleted]
     Where [Deleted].[CountryId] = '36bd1536-fb56-4ec4-957e-1b3afde16c56') = 1)
BEGIN       
    RAISERROR('You can not delete this specific record!', 0, 0)
    ROLLBACK TRANSACTION
    RETURN
END
END

如何确保按预期删除不符合上述条件的行？

Answer 1

你有一个 INSTEAD OF 触发器，所以你需要一个实际的 DELETE。

我还考虑简单地过滤掉受保护的行，因为：

• 您需要抛出错误吗？还是默默无视？
• 包含受保护行的多行删除怎么办：中止整个行，还是删除其余行？

类似：

ALTER TRIGGER [Globalization].[CountriesTracker]  ON [Globalization].[Countries] 
 INSTEAD OF DELETE
 AS 
SET NOCOUNT ON;

DELETE
   CT
FROM
   [Globalization].[Countries] C
   JOIN
   DELETED D ON C.CountryId = D.CountryId
WHERE
    [Deleted].[CountryId] <> '36bd1536-fb56-4ec4-957e-1b3afde16c56'
 GO

Answer 2

因为这是 INSTEAD OF，所以您仍然需要对默认情况执行删除操作。