[mol]

كود :

OleDbDataAdapter da = new OleDbDataAdapter(@"SELECT Table_2.ID, SUM(Table_2.Numpr_Total + Table_3.AS_Total) AS total FROM Table_2 INNER JOIN TABLE_3 ON Table_2.ID = Table_3.ID GROUP BY Table_2.ID", cnn);
DataTable dt = new DataTable();
if (da.Fill(dt) > 0)
{
   OleDbCommand cmd;
   if(cnn.State!=ConnectionState.Open)cnn.Open();
   foreach (DataRow r in dt.Rows)
   {
       cmd = new OleDbCommand(@"UPDATE Table_1 SET Total = @total WHERE ID=@id", cnn);
       cmd.Parameters.AddWithValue("@total", r["total"]);
       cmd.Parameters.AddWithValue("@id", r["ID"]);
       cmd.ExecuteNonQuery();
   }
   cnn.Close();
}