Question

I have a query that I want to sort alphabetically, but the trick is that I want the sorting to treat two columns equally. For instance, if the first row of first_col equals apple and the second row of second_col equals aardvark I want the value in the second row of second_col to be listed before the value in the first row of first_col. A value (not NULL or '') will always exist in every row of second_col, but the value in first_col can be ''. Hopefully I have explained this good enough. I don’t care if I have to use MySQL or PHP for this, but once sorted, the array is read through and echoed into an HTML table. Any thoughts?

EDIT

This is what I have for code right now. In my MySQL query I need b_name and l_name to be equal. The column b_name does not always have a value. When I put the values into the table it is based on the existence of b_name. If b_name does not exist the f_name and l_name are combined to replace b_name.

                $query = "SELECT * FROM customers ORDER BY b_name, l_name";
                $result = mysql_query($query);
                mysql_close($link);

                $num = mysql_num_rows($result);                         

                for ($i = 0; $i < $num; $i++){

                    $row = mysql_fetch_array($result);

                    $class = (($i % 2) == 0) ? "table_odd_row" : "table_even_row";

                    if($row[b_name]!=''){
                        echo "<tr class=".$class.">";

                            echo "<td><a href=Edit_Customer.php?c_id=".$row[c_id].">".$row[c_id]."</a></td>";
                            echo "<td><a href=Edit_Customer.php?c_id=".$row[c_id].">".$row[b_name]."</a></td>";
                            echo "<td><a href=Edit_Customer.php?c_id=".$row[c_id].">".$row[phone]."</a></td>";

                        echo "</tr>";

                    }

                    else{
                        echo "<tr class=".$class.">";

                            echo "<td><a href=Edit_Customer.php?c_id=".$row[c_id].">".$row[c_id]."</a></td>";
                            echo "<td><a href=Edit_Customer.php?c_id=".$row[c_id].">".$row[f_name]." ".$row[l_name]."</a></td>";
                            echo "<td><a href=Edit_Customer.php?c_id=".$row[c_id].">".$row[phone]."</a></td>";

                        echo "</tr>";

                    }


                }

            ?>      

        </table>

Answer 1

Thanks for all your help guys, but none of your answers allowed me to sort the data AND echo it into the HTML table correctly once sorted. A UNION might have worked, but I think my solution was faster as far as figuring it all out goes.

                $query = "SELECT c_id, b_name, l_name, f_name, phone FROM customers";
                $result = mysql_query($query);
                mysql_close($link);

                $num = mysql_num_rows($result);

                for ($i = 0; $i < $num; $i++){
                    $row = mysql_fetch_array($result);

                    if($row[b_name]!=''){
                        $new_result[$i]['c_id'] = $row[c_id];
                        $new_result[$i]['c_name'] = $row[b_name];
                        $new_result[$i]['phone'] = $row[phone];
                    }

                    else{
                        $new_result[$i]['c_id'] = $row[c_id];
                        $new_result[$i]['c_name'] = $row[l_name].", ".$row[f_name];
                        $new_result[$i]['phone'] = $row[phone];                         
                    }
                }                       

                foreach ($new_result as $key => $row) {
                   $c_id[$key]  = $row['c_id'];
                   $c_name[$key] = $row['c_name'];
                   $phone[$key] = $row['phone'];
                }

                array_multisort($c_name, SORT_ASC, $c_id, SORT_ASC, $new_result);   

                for ($i = 0; $i < $num; $i++){

                    $class = (($i % 2) == 0) ? "table_odd_row" : "table_even_row";

                    echo "<tr class=".$class.">";

                        echo "<td><a href=Edit_Customer.php?c_id=".$new_result[$i]['c_id'].">".$new_result[$i]['c_id']."</a></td>";
                        echo "<td><a href=Edit_Customer.php?c_id=".$new_result[$i]['c_id'].">".$new_result[$i]['c_name']."</a></td>";
                        echo "<td><a href=Edit_Customer.php?c_id=".$new_result[$i]['c_id'].">".$new_result[$i]['phone']."</a></td>";

                    echo "</tr>";                       

                }

            ?>      

        </table>