Mysql return joined table as sub-array - php

Question

I'm using my mysqli query as JSON output.
This is my query:
$sql = "SELECT p.*,comments.*,COUNT(comments.id) AS numComments FROM people AS p
LEFT JOIN comments ON comments.people_id = p.id
WHERE p.name LIKE '%".$data."%'";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
$myArray[] = $row;
}
echo json_encode($myArray);
} else {
echo 0;
}
What I want to do, is to group all the person comments and place it under the person data. for example:
The desired output is that I will be able to access the comments not directly from the query, but from the person itself.
for example:
echo $person['comment'][0]['content']
Currently, I access it like any of the query data..
echo $person['content']
JSON OUTPUT:
As you can see, the person data and the comment data is mixed in the same array. I want the comments to have an array of their own.
Any ideas?
Edit: Seem like I have problem with the query. it returns only the first comment!

Answer 1

You need so-called eager loading for this task. It will involve two queries, but it will be way better than one.
You have to select your people first, then get people ids and query comments table for the comments. And finally you will have to combine the two arrays together.
I will use PDO as it will take 5 times less code to write, thanks to some neat PDO features.
$stmt = $conn->prepare("SELECT * FROM people WHERE name LIKE ?");
$stmt->execute(["%$data%"]);
$people = $stmt->fetchAll(PDO::FETCH_UNIQUE);
$ids = array_keys($people);
$in = str_repeat('?,', count($ids) - 1) . '?';
$stmt = $db->prepare("SELECT people_id, * FROM comments WHERE people_id IN ($in)");
$stmt->execute($ids);
$comments = $stmt->fetchAll(PDO::FETCH_GROUP);
foreach($people as $id=>$row)
{
$row['comments'] = $comments[$id];
$people[$id] = $row;
}