Query works on localhost, but not in production server - php

Question

My English is not so good, but I'll try to explain the problem.
I have three tables: One called Accounts, one called Accounts_Profiles and another called Accounts_Messages. My goal is to show the last users that the logged in user ($login_user_id) sent a message to.
My tables basically consists of this:
Accounts
id, name, email, nivel, verification
Accounts_Profiles
id, user_id, status
Accounts_Messagens
id, sender (int), receiver (int)
My query is currently like this:
SELECT DISTINCT Accounts.id, Accounts.email, Accounts.name, Accounts.username, Accounts.avatar, Accounts.nivel, Accounts.verification FROM Accounts JOIN Accounts_Messages ON Accounts.id = Accounts_Messages.receiver ORDER BY Accounts_Messages.id DESC;
In CodeIgniter/PHP, it looks like this:
/*
With the $this->db->distinct() I make sure that the users shown will not be repeated - It works!
*/
$this->db->distinct();
$this->db->select(
array(
"Accounts.id id",
"Accounts.email email",
"Accounts.name name",
"Accounts.username username",
"Accounts.avatar avatar",
"Accounts.nivel nivel",
"Accounts.verification verification",
"Accounts_Profiles.status online",
"(SELECT IF(COUNT(ACM.id) > 0, COUNT(ACM.id), null) FROM Accounts_Messages ACM WHERE ACM.receiver = '$login_user_id' AND ACM.sender = 'Accounts.id' AND ACM.is_read = '0') unread"
)
);
/*
Here I exclude the $login_user_id from the list, the admin users and also those who have not verified the account - It works!
*/
$this->db->join(
"Accounts_Profiles",
"Accounts_Profiles.user_id = Accounts.id",
"left"
);
$this->db->where(
array(
"Accounts.id !=" => $login_user_id,
"Accounts.nivel !=" => 'administrator',
"Accounts.verification !=" => 'false'
)
);
/*
Here, I sort messages by last sent. I check who the logged in user sent the last messages to and list those users - This only works on localhost.
*/
$this->db->join(
"Accounts_Messages",
"Accounts.id = Accounts_Messages.receiver",
"left"
);
$this->db->order_by(
"Accounts_Messages.id", 'DESC'
);
/*
Returning the result
*/
return $this->db->limit($filters['limit'])->offset($filters['offset'])->get("Accounts")->result();
The problem:
This works on localhost, but it doesn't work in production. On localhost I use MySQL. On the production server I use MariaDB.
In theory it shouldn't make any difference, since the clauses I used are compatible in both cases.
Am I forgetting to do something or some configuration on the production server?
Thank you!
I tried to add this for conscience sake, but it didn't work:
$this->db->group_by( "Accounts.id" );
Edit
As you can see, in localhost the ordering of users is given by the last message sent to them. That's what I expect in production.
On the production server the ordering is happening by conversation creation date (I don't know how). It's wrong, as the first users I chat with always come last even if I send them a new message.

Answer 1

Solution
I managed to solve the problem by doing the following adjustment in the query:
SELECT Accounts.id, Accounts.email, Accounts.name, Accounts.username, Accounts.avatar, Accounts.nivel, Accounts.verification, Accounts_Messages.id
FROM Accounts
JOIN (
SELECT m_to, MAX(dt_updated) as max_updated
FROM Accounts_Messages
GROUP BY m_to
) last_message
ON Accounts.id = last_message.m_to
JOIN Accounts_Messages
ON Accounts.id = Accounts_Messages.m_to AND Accounts_Messages.dt_updated = last_message.max_updated
GROUP BY Accounts.id, Accounts_Messages.id
ORDER BY last_message.max_updated DESC;
It looks like this in CodeIgniter:
<?php
/*
With the $this->db->distinct() I make sure that the users shown will not be repeated
*/
$this->db->distinct();
$this->db->select(
array(
"Accounts.id id",
"Accounts.email email",
"Accounts.name name",
"Accounts.username username",
"Accounts.avatar avatar",
"Accounts.nivel nivel",
"Accounts.verification verification",
"Accounts_Messages.id acmid",
"Accounts_Profiles.status online",
"(SELECT IF(COUNT(ACM.id) > 0, COUNT(ACM.id), null) FROM Accounts_Messages ACM WHERE ACM.m_to = '$login_user_id' AND ACM.m_from = 'Accounts.id' AND ACM.is_read = '0') unread"
)
);
/*
Here I exclude the $login_user_id from the list, the admin users and also those who have not verified the account
*/
$this->db->join(
"Accounts_Profiles",
"Accounts_Profiles.user_id = Accounts.id",
"left"
);
$this->db->where(
array(
"Accounts.id !=" => $login_user_id,
"Accounts.nivel !=" => 'administrator',
"Accounts.verification !=" => 'false'
)
);
/*
Here, I sort messages by last sent. I check who the logged in user sent the last messages to and list those users
*/
$this->db->join(
"(SELECT m_to, MAX(dt_updated) as max_updated FROM Accounts_Messages GROUP BY m_to) last_message",
"Accounts.id = last_message.m_to",
'inner'
);
$this->db->join(
"Accounts_Messages",
"Accounts.id = Accounts_Messages.m_to AND Accounts_Messages.dt_updated = last_message.max_updated",
'inner'
);
$this->db->group_by(
"Accounts.id, Accounts_Messages.id"
);
$this->db->order_by(
"last_message.max_updated",
"DESC"
);
?>