SQL CONNECTION OPEN EXCEPTION

Andrew Watson

Total Post:39

Points:273
Posted by  Andrew Watson
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I am working on a project which, up until today, has been fine. However now when I run it and it goes through a few different Stored Procedure calls it is throwing an InvalidOperationException with the message The connection was not closed. The connection's current state is open.

 

I get that I could put in a check to see if the connection is already open, but this code hasn't changed (it is under Version Control and isn't modified) so I'm looking for other potential explanations.

 

Could there be some lock in SQL which isn't being released? Is there a process which I should look out for and kill?

 

I can't really post the code as there is a lot of it, and it is split up into smaller methods which makes it harder to pull out individual items. E.g:

 

public SqlConnection Connection

{

    get

    {

        this._connection.Open();

        return _connection;

    }

}

 

public IDataReader RetrieveRecord(int Id)

{

    //SP

    SqlCommand cmd = this.Connection.CreateCommand();

cmd.CommandText = "SelectRecord";

    cmd.CommandType = CommandType.StoredProcedure;

 

    //Parameters

    cmd.Parameters.Add(new SqlParameter("@tID", Id));

 

    //instruct the data reader to close its connection when its Close method is         called by passing the CommandBehavior.CloseConnection

    return cmd.ExecuteReader(CommandBehavior.CloseConnection);

}

Nothing massively complex, I just don't understand why this connection is now throwing an exception.

  1. Chris S

    Post:48

    Points:336
    Re: SQL Connection Open Exception

    Problem is with the line

     

    this._connection.Open();

    Because you are trying to open an already opened connection.

     

    Try this to check before opening a connection:

     

     if (this._connection.State == ConnectionState.Closed)

                this._connection.Open();

  1. Allen Scott

    Post:46

    Points:324
    Re: SQL Connection Open Exception

    When you are talking about killing process, I think you know c# well.

     

    You should always use

     

    using()

    {

     

    }

    Like:

     

    using(SqlConnection con=new SqlConnection("connectionString"))

    {

      // Do something with con

         using(SqlCommand cmd=new SqlCommand("cmdText",con))

         {

            // Do something with cmd

         }

    }

    You know that SqlCommand and SqlConnection implement IDisposable

    So when you put those objects within using, the connection closing and clean up job is automatically done.

    No need to close the connection manually in the code, since using will do the work for you.

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