Question

I just submitted my work and my course leader has asked me to use PHP functions to query my database. How can I do this? Is it possible to add just “function getRooms” before my queries, and return the desired result. I need thorough briefing on functions with MySQL.

For example:
How will I add a function to this code:

<?php
    // By Kelvin
    include ("player.php");
    $result = mysql_query("SELECT * FROM phplogin WHERE username = '$username'");
    $row = mysql_fetch_assoc($result);
    $medipack = $row['medipack'];
    if ($_POST['object'] == "Use Medipack") {
        if ($medipack != 0) {
            mysql_query("UPDATE phplogin SET score = score + 50, health = health + 50, medipack = medipack - 1
            WHERE username = '$username'");
            echo ("<P>Medipack Used!</P>");
            $RoomNumber =5;
        }
        else {
            echo ("<P>You're all out of medipacks!</P>");
        }
    }
?>

Answer 1

If he’s looking for a level of abstraction between the rest of your code and the code accessing the database, wrapping the database logic in functions should be on the right path:

function getRooms($link){
    $sql = "SELECT * FROM rooms";
    $data = array();
    if($set = mysql_query($sql)){
        while($row = mysql_fetch_assoc($set)){
            $data[] = $row;
        }
    }
    return empty($data)
        ? null
        : $data;
}

$db_connection = mysql_connect('host', 'user', 'pass');
mysql_select_db('name', $db_connection);
$rooms = getRooms($db_connection);

Wrapping these functions into a class, and accessing them by methods is another step, as the instantiated object can manage its own connection, etc., but that may be a step further than necessary. Other functions (based on what I can guess) might be:

function getRoomById($link, $id){ }
function getRoomsByName($link, Array $names){ }