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@@identity

    問題

  • I'm having the issue where @@identity returns null.

    I've seen several responses that @@identity is a session variable.

    I'm coding directly with ado.net(sqlserverce)

    I execute my insert and then do a select for @@identity.

    I don't see the connection state changing to closed between the calls.

    In addition I get the exact same behavior if I run the query analyzer.

    Most posts I see mention the query analyzer works for them with @@identity.

    Is there som property of the engine I need to set or something?

    I'm running sqlserverce 4 swith visual studio 2011.

    2012年5月29日 下午 06:41

所有回覆

  • oops visual studio 2010.

    here's the code:

     

    sqlcecommand.CommandText() ="insert into clients (client_name) values('"+ clientname + "')"

    recordcount = sqlcecommand.ExecuteNonQuery()

    sqlcecommand.CommandText = "select @@identity"

    Dim test As Object = sqlcecommand.ExecuteScalar

    2012年5月29日 下午 07:11
  • Hi Mgarner1980,

    Regarding to your description, the @@IDENTITY is an internal variable which is a session based.  Assuming  when  connection close then you will lost the current session so my next request with a new connection object is in fact a new session.

    The @@IDENTITY returns a decimal value so that it needs to be type casted to an integer. Meanwhile make sure the Insert statement executed success.

    For more information, please refer to the last reply in this thread.


    Regards, Amber zhang

    2012年5月31日 上午 06:42
    版主
  • Thanks,

    What I don't understand is why my connection is being closed. I explicitly open the connection at the beginning of my application and don't close it until the end.

    If I query the state of the connection before or after each command execution ...it is open.

    Actually my code is quite similair to what is the last reply on your suggested thread.

    What i'm confused about is why two commands executed back to back without closing the connection are in different sessions.

    Perhaps there 's some extended parameter of either the connection or command object I don't know about?

    2012年6月1日 下午 03:10