Fill grid view from both XML data and grid data

i have a grid view that contain many fields, here i m retriving data from XML file and want to take one more column from the table also. how can i take that from the table.
this is the below code i have tried to retrive data from XML file
CODE BEHIND
    protected void btnviewdata_Click(object sender, EventArgs e)
    {
        GridView1.Visible = true;
        SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=TNVKP_8;Integrated Security=True");
        con.Open();
        DataSet reportData = new DataSet();
        reportData.ReadXml(Server.MapPath("XMLFILENAME.xml"));
        GridView2.DataSource = reportData;
        GridView2.DataBind();
        con.Close();
    }

ASPX code
                   
                                                 
           
               
                   
               
           
           
           
           
           
           
           
           
                             
           
           
           
               
                   
               
           
           
               
                   
               
           
           
                     


Here in this PIPCODE label i want take data from the sql server
if XML pipno equal my table pipno then i want reteive the equivalent code the pipno.
and how can i write the query to select the pipcode from the table because i want to take the pipno from xml and match with sql then i want to select th equivalent pipcode from table and should view in the last column of grid view.
If pipcode is available the remark equal to OK
if pipno not available then remark equal to NOT IN DB like that
post solution for this 
Thanks in advance