Receiving the error "There is already an open DataReader associated with this Command which must be closed first." [solved]
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I am working to add some additional functionality to a project and without changing anything to a particular form and DataSet object I began getting the error "There is already an open DataReader associated with this Command which must be closed first.". I am using a DataSet object that is actually part of the project which contains 2 datatables. I fill one for a large datagridview and fill the other table based on the row selection in the first. This has been working fine until today. I have already tried the "MultipleActiveResultSets=true;" parameter in the connection string and it makes no difference. Resolution: I just began setting the Dataset connection programmatically to override what was set at design time. I was using the same connection for both table adapters and after letting Ben's response sink in I realized what I was doing. Thanks!
CleaKO
"Now, a man would have opened both gates, driven through and not bothered to close either gate." - Marc Clifton (The Lounge)
modified on Tuesday, November 25, 2008 2:57 PM
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I am working to add some additional functionality to a project and without changing anything to a particular form and DataSet object I began getting the error "There is already an open DataReader associated with this Command which must be closed first.". I am using a DataSet object that is actually part of the project which contains 2 datatables. I fill one for a large datagridview and fill the other table based on the row selection in the first. This has been working fine until today. I have already tried the "MultipleActiveResultSets=true;" parameter in the connection string and it makes no difference. Resolution: I just began setting the Dataset connection programmatically to override what was set at design time. I was using the same connection for both table adapters and after letting Ben's response sink in I realized what I was doing. Thanks!
CleaKO
"Now, a man would have opened both gates, driven through and not bothered to close either gate." - Marc Clifton (The Lounge)
modified on Tuesday, November 25, 2008 2:57 PM
The message means exactly what is says; there is a
DataReadercreated from the command'sExecuteReader()function that has not been closed. You'll have to trace through the code, find it and close it. I think it's common for this kind of thing to be done in afinallyblock, so maybe you inserted code to re-use a command object inside atryblock where aDataReaderis created from the command'sExecuteReader()function and has not been closed since thefinallyblock hasn't executed.Keep It Simple Stupid! (KISS)
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The message means exactly what is says; there is a
DataReadercreated from the command'sExecuteReader()function that has not been closed. You'll have to trace through the code, find it and close it. I think it's common for this kind of thing to be done in afinallyblock, so maybe you inserted code to re-use a command object inside atryblock where aDataReaderis created from the command'sExecuteReader()function and has not been closed since thefinallyblock hasn't executed.Keep It Simple Stupid! (KISS)
If it was the code I wrote I would have all of that done but all I am doing is calling a TableDataAdapter that is created from the .NET Dataset to fill the local datatable contained in my instance of that dataset. As I said before, this was not an issue, I did not change anything and am now having to track it down. Here is the code where it breaks.
<Global.System.Diagnostics.DebuggerNonUserCodeAttribute(), _ Global.System.ComponentModel.Design.HelpKeywordAttribute("vs.data.TableAdapter"), _ Global.System.ComponentModel.DataObjectMethodAttribute(Global.System.ComponentModel.DataObjectMethodType.Fill, false)> _ Public Overloads Overridable Function GetCustomerDetailsCustomerDetailID(ByVal dataTable As CustomerDetail.CustomerDetailsDataTable, ByVal CustomerDetailID As Global.System.Nullable(Of Integer)) As Integer Me.Adapter.SelectCommand = Me.CommandCollection(1) If (CustomerDetailID.HasValue = true) Then Me.Adapter.SelectCommand.Parameters(1).Value = CType(CustomerDetailID.Value,Integer) Else Me.Adapter.SelectCommand.Parameters(1).Value = Global.System.DBNull.Value End If If (Me.ClearBeforeFill = true) Then dataTable.Clear End If Dim returnValue As Integer = Me.Adapter.Fill(dataTable) Return returnValue End Function
CleaKO
"Now, a man would have opened both gates, driven through and not bothered to close either gate." - Marc Clifton (The Lounge)