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ADO.Net Deletes From Dataset but Not Database

kmcbrearty
kmcbrearty asked
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Last Modified: 2010-04-23
As mentioned in the title the code that I have to delete a record will delete it from the dataset but not from the database.  The other code that I have to Add, Update, and Select records works fine, but for some reason my delete is not working.  Can anyone offer some suggestions on how to resolve this.  I am fairly new to using ADO.Net but I would like to be able to start using it.

In case anyone is wondering why I am not using the wizards I am trying to create a data class that will be consumed by the actual application.  There is no visual representation here.  I would also like to get familiar with the actual code since it always gives you more control.

Here is the Code:

---------------------------------------------------------------------------------------
Constructor
---------------------------------------------------------------------------------------
        Private Sub New()
            Try
                ' Get Connection and Open Connection
                sqlConn = Functions.GetConnection

                '
                ' Select Command
                '
                With cmdSelect
                    .CommandText = "Select * from tblManufacturerGeneral"
                    .Connection = sqlConn
                End With
               
                '
                ' Insert Command
                '
                With cmdInsert
                    .CommandText = "INSERT INTO tblManufacturerGeneral " & _
                                   "(MBusGUID, Commission, CreationDate, ModifyDate) " & _
                                   "VALUES " & _
                                   "(@MBusGUID, @Commission, @CreationDate, @ModifyDate)"
                    .Connection = sqlConn
                    With .Parameters
                        .Add("@MBusGUID", SqlDbType.UniqueIdentifier, 16, "MBusGUID")
                        .Add("@Commission", SqlDbType.Decimal, 18, "Commission")
                        .Add("@CreationDate", SqlDbType.DateTime, 8, "CreationDate")
                        .Add("@ModifyDate", SqlDbType.DateTime, 8, "ModifyDate")
                    End With
                End With
               
                '
                ' Update Command
                '
                With cmdUpdate
                    .CommandText = "UPDATE [tblManufacturerGeneral] " & _
                                   "SET MBusGUID = @MBusGUID, Commission = @Commission, CreationDate = @CreationDate, ModifyDate = @ModifyDate " & _
                                   "WHERE MBusGUID = @MBusGUID"
                    .Connection = sqlConn
                    With .Parameters
                        .Add("@MBusGUID", SqlDbType.UniqueIdentifier, 16, "MBusGUID")
                        .Add("@Commission", SqlDbType.Decimal, 18, "Commission")
                        .Add("@CreationDate", SqlDbType.DateTime, 8, "CreationDate")
                        .Add("@ModifyDate", SqlDbType.DateTime, 8, "ModifyDate")
                    End With
                End With
               
                '
                ' Delete Command
                '
                With cmdDelete
                    .CommandText = "DELETE " & _
                                   "FROM tblManufacturerGeneral " & _
                                   "WHERE MBusGUID = @MBusGUID"
                    .Connection = sqlConn
                    With .Parameters
                        .Add("@MBusGUID", SqlDbType.UniqueIdentifier, 16, "MBusGUID")
                    End With
                End With

                ' Configure the Data Adapter
                myDataAdapter.SelectCommand = cmdSelect
                myDataAdapter.UpdateCommand = cmdUpdate
                myDataAdapter.DeleteCommand = cmdDelete
                myDataAdapter.InsertCommand = cmdInsert
                myDataAdapter.MissingSchemaAction = MissingSchemaAction.AddWithKey

                ' Fill the Dataset
                myDataAdapter.Fill(myDataset, "tblManufacturerItems")
            Catch ex As Exception
                'TODO Add Error Handler
            End Try
        End Sub
---------------------------------------------------------------------------------------
Delete Procedure
---------------------------------------------------------------------------------------
        Public Sub DeleteRecord(ByVal BusGUID As String)
            Dim drMItems As DataRow

            If Exists(BusGUID) Then
                drMItems = myDataset.Tables(0).Rows.Find(BusGUID)
                myDataset.Tables(0).Rows.Remove(drMItems)
                myDataAdapter.Update(myDataset.Tables(0))
            Else
                'TODO: Add Error Handler
            End If
        End Sub
Comment
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Commented:
If found the solution.

---------------------------------------------------------------------------------------
New Delete Procedure
---------------------------------------------------------------------------------------

Public Sub DeleteRecord(ByVal BusGUID As String)
            Dim drMItems As DataRow
            Dim rowIndex As Long

            If Exists(BusGUID) Then
                drMItems = myDataset.Tables(0).Rows.Find(BusGUID)
                rowIndex = myDataset.Tables(0).Rows.IndexOf(drMItems)

                myDataset.Tables(0).Rows(rowIndex).Delete()
                myDataAdapter.Update(myDataset.Tables(0))
            Else
                'TODO: Add Error Handler
            End If
        End Sub
Commented:

Write one more statement after updating the dataset

i.e. After Statement
myDataAdapter.Update(myDataset.Tables(0))

write :
myDataSet.AcceptChanges()

Try it

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Commented:
You could also use this to update all your changes made to the dataset


Public Sub UpdateDatabase()

Dim cb As New OleDb.OleDbCommandBuilder(da)

da.Update(myDataset, "tblManufacturerGeneral")

MsgBox("Data updated")
End Sub

Checkout this tutorial on working with dataset's. Gives you multiple posibilyties with a minimum of code effort and code lines.
I fased out all my old ado concepts after going through this ! (takes about half an hour)

http://www.homeandlearn.co.uk/NET/nets12p9.html

And here from the begining

http://www.homeandlearn.co.uk/NET/nets12p4.html

vbturbo
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