public boolean keyExists(BigDecimal primaryKey, String column) throws SQLException {
         Connection con = null;
         PreparedStatement ps= null;
         ResultSet rs=null;
         int count=0;
         try {
             con = DBConnect.getConnection();
             if (column.equalsIgnoreCase("product_id")) {
                 column="product_id";
                 ps=con.prepareStatement("select count(*) from CSC342.Product where product_id=?");
             } else if (column.equalsIgnoreCase("material_id")) {
                 column="material_id";
                 ps=con.prepareStatement("select count(*) from CSC342.Raw_Material where material_id=?");
             } else {
                 return false;
             }


             //ps.setString(1,column);
             ps.setBigDecimal(1,primaryKey);
             rs=ps.executeQuery();
             rs.next();
             //System.out.println(count);
             count=rs.getInt(1);
         }catch(SQLException e)
         {
             System.out.println("Error in keyExists access: " + e.getSQLState());
             System.out.println("/nError Code: " + e.getErrorCode());
             System.out.println("/nMessage: " + e.getMessage());
             System.exit( 1 );
         }
         catch(Exception e)
         {
             System.out.println("unknown Error in keyExists");
             System.out.println("/nMessage: " + e.getMessage());
             System.exit( 1 );
         }
         finally
        {
            if (con != null)
                System.out.println("closing Uses connection \n");
                rs.close();
                ps.close();

        }
         if (count==1) {
             return true;
         } else {
             return false;
         }
     }