SQL groupping by date and host address - php

Question

I'm trying to count the unique visitors each day on my website.
This is the script i made:
<?php
require_once 'database.php';
$dateQuery = $db->prepare("SELECT count(*) AS hits FROM tracked GROUP BY DATE(date), hostadrr");
$dateQuery->execute();
$rows = $dateQuery->fetchAll(PDO::FETCH_ASSOC);
$array = array();
foreach ( $rows as $row ) {
$array[] = [(int)$row['hits']];
}
$json = json_encode($array);
echo $json;
?>
This array I get from the json_encode is then this:
[[3],[1],[1],[2],[10],[3],[1],[2]]
It is correct that there are 8 arrays inside an array, this represents each day. But the number inside each array are just the total number on clicks on my website, not grouped by the host address of the user. What am i doing wrong here? The array should be: [[1],[1],[1],[1],[1],[1],[1],[1]] (because i'm testing it on my own computer ;) )

Answer 1

First of all, always try to strip down your code to the minimal problem. For example, don't mix JSON encoding, PHP and MySQL and be astonished, that the result isn't what you look like.
Start with the SQL query:
SELECT count(*) AS hits FROM tracked GROUP BY DATE(date), hostadrr
Did you try to run that on console or in phpMyAdmin? Is the correct result showing up?
I would guess not. Why? Because this query only returns a number of hits without any relation to a date or a host address. So, even though you say that the data is correct for the total hits in a day, you can't even be sure if it is the right order or if it doesn't leave out days without any hits.
Since you do not provide your SQL schema, I can only assume one. But your query should at least look something like this:
SELECT
date AS date,
hostadrr AS host,
count(*) AS hits
FROM
tracked
GROUP BY
DATE(date),
hostadrr
ORDER BY
date ASC
Now, you'll get one line for each date/host combination along with the respective number of hits and you can assign that to an array, i.e.
$array[$row['date']][$row['host]] = (int) $row['hits'];