How can I store this data in arrays - php

Question

I have 3 tables users alerts and articles a user can setup an alert so when a new article is added that match his profile he will get an email
I am trying to write a small code to do this task
and this is what I came up with so far
$query_users = "SELECT * FROM `users`";
$result_users = $conn->query($query_users);
while ($users = mysqli_fetch_row($result_users)) {
$user_id = $users[0];
$user_email = $users[1];
$query_alerts = "SELECT * FROM `alerts` where user_id='$user_id' and active= '1' ";
$result_alerts = $conn->query($query_alerts);
while ($alerts = mysqli_fetch_row($result_alerts)) {
$category = mysqli_real_escape_string($conn,$alerts[2]);
$keyword = mysqli_real_escape_string($conn,$alerts[3]);
$query_search = "SELECT * FROM `articles` WHERE `category_id` = '$category' `title` LIKE '%$keyword%' ORDER BY `articles`.`id` ASC ";
$result_search = $conn->query($query_search);
$count = $result_search->num_rows;
}
}
Now what I want to do is to store the result this way
Put each alert category + keyword + count in an array then put it in an array that contain the user id and email
So at the bottom I can loop through the users and send to the user with id 1 and email example#website.com
a table like this
Category | Keyword | articles count
Health | Diet | 5
Buisness | Banks | 2
I hope you understood my idea, I am very confused and dizzy I didn't even know what to type in the search box

Answer 1

Take one array outside of while and add 3 variable in array when loop is executed.
i added 2 lines in your code which are.
$response = array();
and
$response[] = array
(
'category' => $category,
'keyword' => $keyword,
'count' => $count
);
Complete example
<?php
$query_users = "SELECT * FROM `users`";
$result_users = $conn->query($query_users);
$response = array();
while ($users = mysqli_fetch_row($result_users))
{
$user_id = $users[0];
$user_email = $users[1];
$query_alerts = "SELECT * FROM `alerts` where user_id='$user_id' and active= '1' ";
$result_alerts = $conn->query($query_alerts);
while ($alerts = mysqli_fetch_row($result_alerts))
{
$category = mysqli_real_escape_string($conn,$alerts[2]);
$keyword = mysqli_real_escape_string($conn,$alerts[3]);
$query_search = "SELECT * FROM `articles` WHERE `category_id` = '$category' `title` LIKE '%$keyword%' ORDER BY `articles`.`id` ASC ";
$result_search = $conn->query($query_search);
$count = $result_search->num_rows;
$response[] = array
(
'category' => $category,
'keyword' => $keyword,
'count' => $count
);
}
}
echo "<pre>";
print_r($response);