TExecuteReaderCmd RSS

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  clembo67

  Member

  100 Points

  179 Posts

  TExecuteReaderCmd

  Nov 03, 2007 06:37 AM|LINK

  I have modified DAL code to work with ms access database.

  But after this system shows an error during the code execution:  

   Private Sub TExecuteReaderCmd(Of T)(ByVal sqlCmd As OleDbCommand, ByVal gcfr As TGenerateListFromReader(Of T), ByRef List As List(Of T))
  
              If ConnectionString = String.Empty Then
                  Throw New ArgumentOutOfRangeException("ConnectionString")
              End If
  
              If sqlCmd Is Nothing Then
                  Throw New ArgumentNullException("sqlCmd")
              End If
           
              Using cn As OleDbConnection = New OleDbConnection(Me.ConnectionString)
  
                  sqlCmd.Connection = cn
                  cn.Open()
                  sqlCmd.ExecuteReader()
                  gcfr(sqlCmd.ExecuteReader(), List)
  
              End Using
  
          End Sub

  The error is: There is alredy an open DataReader associated with this Connection which must be closed first” 

   After this I have modified the code. I have skip first sqlcmd.execution ( sqlCmd.ExecuteReader()) and it works,

  It's right?

  Why this?

  And what do the first sqlCmd.ExecuteReader() if I skip it without problem?
  

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  chetan.sarod...

  All-Star

  65839 Points

  11163 Posts

  Re: TExecuteReaderCmd

  Nov 05, 2007 02:39 AM|LINK

  You have written following line 

  sqlCmd.ExecuteReader()
  gcfr(sqlCmd.ExecuteReader(), List) i.e. you are executing 2 times ExecuteReader()

  But for that first you have to close first one again then open

  sqlCmd.ExecuteReader()

  sqlCmd.Connection.Close();

  sqlCmd.Connection.Open();
  gcfr(sqlCmd.ExecuteReader(), List)

   

  Chetan Sarode
  Senior Software Engineer,
  Approva Systems Pvt Ltd, Pune, India.