Setting PHP Query into a nested array - php

Question

I am trying to use PHP to logically store all of that data in a nested associative arrays, and then whenever I loop through the data or need to reference the data I would refer to the array pointer rather than doing new queries each time.
For example:
My query is
$query = $db->query("
SELECT
c.id campaign_id,
c.campaign_title,
c.start_date campaign_start_date,
c.end_date campaign_end_date,
cat.id category_id,
cat.category_title,
n.id nominee_id,
n.title nominee_title,
u.id voter_id,
u.fullname voter_name
FROM
campaign c
LEFT JOIN categories cat ON cat.campaign_id = c.id
LEFT JOIN category_nominees cn ON cn.category_id = cat.id
LEFT JOIN nominees n ON n.id = cn.nominee_id
LEFT JOIN category_votes cv ON cv.campaign_id = c.id
AND cv.category_id = cat.id
AND cv.nominee_id = n.id
LEFT JOIN users u on u.id = cv.user_id
WHERE
c.active = 1
ORDER BY
u.fullname,
c.campaign_title,
cat.category_order,
cat.category_title,
cn.nominee_order,
n.title
") or die(mysqli_error());
and im trying to set up the nested array like
$array = array() ;
while($row = mysqli_fetch_assoc($query)) {
$array[$row['campaign_id']] = $row['campaign_id'];
$array[$row['campaign_id']]['campaign_title'] = $row['campaign_title'];
$array[$row['campaign_id']]['campaign_start_date'] = $row['campaign_start_date'];
$array[$row['campaign_id']]['campaign_end_date'] = $row['campaign_end_date'];
$array[$row['campaign_id']]['campaign_title'] = $row['campaign_title'];
$array[$row['campaign_id']]['category_id'] = $row['category_id'];
$array[$row['campaign_id']]['category_id']['category_title'] = $row['category_title'];
}
So whenever I point to:
$array[2][3]['category_title']
It would print the category title
Do you have any ideas? I literally been at it for months and can't figure it out.

Answer 1

Use the following:
while ($row = mysqli_fetch_assoc($query)) {
if (!isset($row['campaign_id'])) {
$array[$row['campaign_id']] = $row;
}
if (!isset($array[$row['campaign_id']]['categories'])) {
$array[$row['campaign_id']]['categories'] = array();
}
$array[$row['campaign_id']]['categories'][$row['category_id']] = array('category_id' => $row['category_id'], 'category_title' => $row['category_title']);
}
}
$row is already an associative array, you don't need to assign each element separately. You only need to deal specially with the category information, which has to be put into a nested associative array that I've called categories. So you would access it as
$array[0]['categories'][1]['category_title']
You can loop over all the categories with:
foreach ($array[$campaign]['categories'] as $cat) {
echo "Category ID: {$cat['category_id']} Title: {$cat['category_title']}<br>";
}