How to Display Values not exist on Lookup(DB)?

 PartNumbers Loaded :
                     P0001        - Not on DB
                     P0002        - Not on DB
                     P0003        - On DB
                     P0004        - On DB

Code:

     int i = 0;
        //Loop Records per Row
        foreach (var serverA in load)
        {

              var obj = new Bal();
              var ent = new Entity
                      {
                      PartNumber = serverA.PartNumber.ToString()
                      };


                      _dSet = obj.SelectPartNumber(ent);

                     //CHECK IF PART NUMBER EXIST ON DB
                     if (_dSet.Tables[0].Rows.Count > 0)
                         {

                         }
                         else
                         {
                            i++; //Count Part Numbers not exist on  DB
                         }

       }
    lblStatus.Text = i > 0 ? @"PartNumbers not on DB" : @"Data has been Loaded";

In this Code:( i ) value is equal to 2 and Display PartNumbers not on DB.

My Problem is how can i displ开发者_Go百科ay the part numbers that do not exist on DB and display it on any container(Message Box etch.).

Ex:
    PartNumber Not on DB
           P0001
           P0002

Thanks in Regards!

Where you're incrementing the count you probably want to add the part number to a list. you can then use the list to generate the text to display. Using a StringBuilder instead of a list would probably work okay, too.

 //CHECK IF PART NUMBER EXIST ON DB
                    if (_dSet.Tables[0].Rows.Count > 0)
                    {

                    }
                    else
                    {
                        i++;
                        builder.Append(serverA.Partnumber.ToString()).AppendLine();
                    }

                }


                if(i > 0 )
                {
                    MessageBox.Show(builder.ToString());
                }
                else
                {
                    lblStatus.Text =  @"Data has been Loaded";
                }