Dim colMaster As DataColumn = dsSpec.Tables("Module").Columns( _
              "LFDNR")
            Dim colDetail As DataColumn = dsSpec.Tables("Data").Columns("POSID")
 
            Dim rel_Module_Data = New DataRelation("Module_Data", colMaster, _
              colDetail)
 
            dsSpec.Relations.Add(rel_Module_Data)
 
            cmd.Connection = con
            cmd.CommandText = "SELECT * FROM Module"
            da.SelectCommand = cmd
 
            da.Fill(dsSpec, "Module")