PHP Undefined offset: 0

I am having troubles with this part

    ";

    $primary_image = dbSelect($db, $query);
    $project->primary_image = $primary_image[0];

    }

of this code

<?php

require_once('includes/config.php');

    enter code here

require_once('includes/lib.php');

$db = dbConnect();

$query = "SELECT projects.* FROM projects ORDER BY rank ASC";
$projects = dbSelect($db, $query);

foreach($projects as $project) {
    $query = "
        SELECT media.* FROM media
        WHERE media.project_id = '$project->id'
        AND media.primary = '1'
    ";

    $primary_image = dbSelect($db, $query);
    $project->primary_image = $primary_image[0];

    }

dbClose($db);

?>

<!DOCTYPE html>
<html>
<head>
<title>Missy Skae's Portfolio</title>
<link rel="stylesheet" href="style.css">
</head>
<body>

<?

foreach($projects as $project) {
    ?>
    <div class="project">
        <h2><?=$project->date;?></h2>
        <h1><a href="project.php?id=<?=$project->id;?>"><?=$project->title;?></a></h1>
        <div class="primary-image">
            <a href="project.php?id=<?=$project->id;?>"><img src="media/<?=$project->primary_image->filename;?>"></a>
        </div>
        <h2><?=$project->tag1;?></h2>
        <h1><?=$project->description;?></h1>
    </div>
    <?
}

?>

</body>
</html>

the error being Notice: Undefined offset: 0

Anyone have any ideas? Thanks!

Solution

The notice should give you a line number, Can you provide it.

In your query, You should update this line:

    WHERE media.project_id = '$project->id'

to read

    WHERE media.project_id = '{$project->id}'

I beleive it would cause an error.

It's difficult to pinpoint the error without knowing what line this is happening on or whats in the other included files. It's more than likely on this line..

$project->primary_image = $primary_image[0];

You could test it by using a var_dump on $primary_image, like so

$primary_image = dbSelect($db, $query);
var_dump($primary_image);
$project->primary_image = $primary_image[0];