Question

我有一个FileTable FT和另一个表AT。在AT中，我在FT中扩展了文件的元数据属性。

我尝试创建一个触发器ON FT FOR UPDATE，它将更新AT中的文件路径。

以下是我尝试的内容：

ALTER TRIGGER [dbo].[u_filepath] 
ON [FileDB].[dbo].[FT] 
FOR UPDATE
AS
    Declare @newpath nvarchar(1000)
    Declare @oldpath nvarchar(1000)

    select @newpath = file_stream.pathname()
    from inserted

    select @oldpath = file_stream.pathname()
    from deleted

    update AT
    set [Path] = @newpath
    where [Path] = @oldpath
GO

当我执行查询时，它会旋转。我计划让它一夜之间运行，以防它决定做某事。

我希望Path中的AT列从file_stream.PathName()更新为更新的FT。

触发器是否合乎逻辑？

我应该将file_stream BLOB存储在AT Path列而不是实际路径吗？

Answer 1

您的触发器有 MAJOR 缺陷，因为您似乎认为它将被称为每行一次 - 这是不的情况。

触发器会在每个语句时触发，因此，如果导致此触发器的2016-03-01 18:59:40 11872 [ERROR] InnoDB: File .\newdb\answer.ibd: 'open' returned OS error 1379. Cannot continue operation 2016-03-01 19:00:16 2eb8 InnoDB: Warning: Using innodb_additional_mem_pool_size is DEPRECATED. This option may be removed in future releases, together with the option innodb_use_sys_malloc and with the InnoDB's internal memory allocator. 2016-03-01 19:00:16 11960 [Note] InnoDB: Using mutexes to ref count buffer pool pages 2016-03-01 19:00:16 11960 [Note] InnoDB: The InnoDB memory heap is disabled 2016-03-01 19:00:16 11960 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions 2016-03-01 19:00:16 11960 [Note] InnoDB: Memory barrier is not used 2016-03-01 19:00:16 11960 [Note] InnoDB: Compressed tables use zlib 1.2.3 2016-03-01 19:00:16 11960 [Note] InnoDB: Using generic crc32 instructions 2016-03-01 19:00:16 11960 [Note] InnoDB: Initializing buffer pool, size = 16.0M 2016-03-01 19:00:16 11960 [Note] InnoDB: Completed initialization of buffer pool 2016-03-01 19:00:26 2eb8 InnoDB: Operating system error number 1179 in a file operation. InnoDB: Some operating system error numbers are described at InnoDB: http://dev.mysql.com/doc/refman/5.6/en/operating-system-error-codes.html InnoDB: Operation open to file os\os0file.cc and at line 2041 2016-03-01 19:00:26 11960 [ERROR] InnoDB: File G:\Xampp\mysql\data\ibdata1: 'open' returned OS error 1379. Cannot continue operation语句触发插入25行，则会触发触发器一次，但UPDATE和Deleted伪表将包含25行。

您的代码会选择这25行中的哪一行？

Inserted

这是非确定性的，你会得到一行，你将忽略所有其他行。

您需要重写触发器才能将此考虑在内 - 使用基于集合的方法更新数据 - 而不是基于行的数据 - 如下所示：

select @newpath = file_stream.pathname() from inserted

SQL Server 2014：更新File_Stream.PathName（）时的FileTable触发器

1 个答案: