Problem in delete records

[sacramento]

hi to all:

I would like to delete all records in an field of my database and I have this code:

Dim sql1 As String
        
        Dim connection As New OleDb.OleDbConnection(String.Format("PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source = " & drive & IDempresa))
        connection.Open()
        
        Dim adapter As OleDb.OleDbDataAdapter

        sql1 = "select *" & _
        " from balancetegeral" & _
        " order by id"

        adapter = New OleDb.OleDbDataAdapter(sql1, connection)
        Dim commandbuilder As New OleDb.OleDbCommandBuilder(adapter)
        adapter.DeleteCommand = commandbuilder.GetDeleteCommand
        
        Dim dt As New DataTable
        adapter.Fill(dt)

        
        For Each r As DataRow In dt.Rows
            If r.Item("mensaisdebito") Then
                r.Delete()
            End If
        Next

        'Update database.  
        adapter.Update(dt)

        connection.Close()

In the instruction in bold I have this error:
Conversion from type 'DBNull' to type 'Boolean' is not valid.

Any help please

Thanks

[Hack]

Why not just use a garden variety SQL DELETE query?

[sacramento]

Sory but with VS2008 i don't know do this...
Can you tell me the way to do?

Thanks

[Campion]

It's not a VB2008 thing. It's a ADO.NET thing.

Dim MyCom as new OledbCommand("DELETE FROM Table WHERE Column IS NOT NULL", Conn)

try
   MyCom.Executenonquery
catch ex as OledbException
   
end try

[sacramento]

ok...sory

Thanks

[Hack]

Nothing to be sorry for....you might find this of interest.

http://www.vbforums.com/showthread.php?t=466658

[sacramento]

yes...it is

[Campion]

If you say so. I was simply pointing out that you were blaming the wrong thing. If you didn't know, then now you do. It's all a part of learning.

[sacramento]

No doubt...and I'm thankfull for all this posts...
I'm learn day by day,and off course the VBforums it's my house to learn more and more...