How to display some columns of database

You can use this method

 SqlCommand com = new SqlCommand("select * from TblMaster_Main_Category",con);
//This query will return a collection of all column of table TblMaster_Main_Category

        SqlDataAdapter da = new SqlDataAdapter(com);
        DataTable tab = new DataTable();
        da.Fill(tab);
//WE take a new table
        DataTable tab2 = new DataTable();
        DataRow[] tb=new DataRow();
      tb=  tab.Select("select Serial_Order,nvCategory_Name");
// this query return a collection of all column which you want to select


      foreach (DataRow dr in tb)
      {
          tab2.Rows.Add(dr);
      }

      tab2.AcceptChanges();

// Now you can Binf this table to your gridview