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PHP

Posted by Kane Stoboi
Kane Stoboi
21,919 Points

Page not loading once function is called.

I'm calling a function to delete all data within a MySQL table using the code below.

<?php
require_once("../includes/config.php");
require_once(ROOT_PATH . "includes/functions.php");

delete_reference_list();

$referenceList = get_reference_list_harvard();
include(ROOT_PATH . "includes/header.php");
?>

    <div id="wrapper">
        <h2>Reference List</h2>

        <?php
        foreach ($referenceList as $reference) {
            echo "<div class='reference_list'>" . $reference . "</div>";
        }


        ?>


    </div>
    </body>

</html>

Here's the function being called from functions.php

<?php
function delete_reference_list() {

    require_once(ROOT_PATH . "includes/database.php");
    try {
        $db->query("DELETE FROM reference_list");
        echo "success";
    } catch (Exception $e) {
        echo $e;
    }
    return null;
}
?>

It seems that if I remove the $referenceList variable the page works but if I have both $referenceList and the delete_reference_list() function there is some sort of error somewhere.

Christian Andersson
Christian Andersson
8,712 Points

what error are you getting?

Kane Stoboi
Kane Stoboi
21,919 Points

The page just loads "success" and does not load any further

Kane Stoboi
Kane Stoboi
21,919 Points

I'm getting this php error:

Notice: Undefined variable: db in /Applications/MAMP/htdocs/reference/includes/functions.php on line 854

Fatal error: Call to a member function prepare() on a non-object in /Applications/MAMP/htdocs/reference/includes/functions.php on line 854

Here's the code between 849 and 860

<?php
function get_reference_list_harvard() {

    require_once("database.php");

    try {
        $query = $db->prepare("SELECT * FROM reference_list"); //(line 854)
        $query->execute();
        $results = $query->fetchall(PDO::FETCH_ASSOC);  
    } catch (Exception $e) {
        echo "Data could not be retreived from the database: " . $e;
        exit;
    }

and the database file

<?php
try {
    $db = new PDO("mysql:host=localhost;dbname=reference_list;port=8889", "root", "root");
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $db->exec("SET NAMES 'utf8'");
} catch (Exception $e) {
    echo "Could not connect to the database";
    exit;
}
Christian Andersson
Christian Andersson
8,712 Points

updated my answer.

1 Answer

Christian Andersson
Christian Andersson
8,712 Points
Christian Andersson
Christian Andersson
8,712 Points

if it doesn't recognize $db as an object, then there might be something wrong with the constructor in your database file.

Also, is your table-name same as the database-name (reference_list)? If not an error, that's an unusual practice.

Kane Stoboi
Kane Stoboi
21,919 Points

Thanks for you help Christian, I've been calling require_once to include the database file instead of require which is why the $db object was not being constructed correctly. Thanks for raising my database name issue, I built it a few days ago and must have overlooked it.