Bug #73447 Information about DataReader open when just using dataadapter
Submitted: 31 Jul 2014 13:44 Modified: 22 Jan 2015 17:07
Reporter: Jorge Bastos Email Updates:
Status: No Feedback Impact on me:
Category:Connector / NET Severity:S2 (Serious)
Version:6.7.4 OS:Any
Assigned to: Assigned Account CPU Architecture:Any

[31 Jul 2014 13:44] Jorge Bastos

In My project I just have two functions, one to execute all non-query tasks, and other to retrieve data, and with this, I have a global connection that is open in the app load, and closed on close, functions are:

(on load)
Public GMyCon as new mysqlconnection("cs with pooling=true)

Function SqlDataTable(ByVal sql_v As String) As DataTable
        SqlDataTable = New DataTable

        If Not GMyCon.Ping Then
        End If

        Dim _MyDa As New MySqlDataAdapter(sql_v, GMyCon)

        _MyDa = Nothing
        Return SqlDataTable
End function
Function Insert_Sql(ByVal sql_v As String, Optional ByVal mCon As MySqlConnection = Nothing) As Int32
        If Not GMyCon.Ping Then
        End If

        Dim _MyCmd As New MySqlCommand(sql_v, GMyCon)
        Dim sql_return As Integer = _MyCmd.ExecuteNonQuery()

        _MyCmd = Nothing

        Return sql_return
End Function

BUT, sometimes, after an extensive use of sqldatatable() function, I get an:

MySql.Data.MySqlClient.MySqlException (0x80004005): There is already an open DataReader associated with this Connection which must be closed first.

which I don't quite understand, cause I don't use the datareader.
Maybe I need to clear the pool before using the dataadaptor like this?

Dim _MyDa As New MySqlDataAdapter(sql_v, GMyCon)

How to repeat:
Using the specified functions.
[22 Dec 2014 17:07] Gabriela Martinez Sanchez
hi Jorge,

I saw your code and most of it looks good to me. Although I would suggest that if your global connection is open all the time when the application is running, then you can change this part of your code:

 If Not GMyCon.Ping Then
 End If

to this:

 If Not GMyCon.State == ConnectionState.Open Then
 End If

Please give it a try and let us know if that helped to avoid the exception.

Thanks in advance!
[23 Jan 2015 1:00] Bugs System
No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".