MySQL what kind of query i need to use - php

Question

i'm making a panel where i can manage my users, i want to show username, email, and i want to show how much orders the placed. In my database i have 2 tabels 1 users, 1 orders. I'm saving the username from the user in the order table so i know wich user has bought it.
But, i want to write a panel with a overview from my users in a foreach loop. I have the loop for username, email how i can add the amount of order to it.
<?php
$model = $connection->createCommand('SELECT * FROM user');
$adminAccounts = $model->queryAll();
foreach($adminAccounts as $results){
$accounts['id'] = $account_id;
$accounts['username'] = $results['username'];
$accounts['email'] = $results['email'];
$accounts['rest'] = $results;
echo "
<tr>
<td>
<p>" . $newValidation->safeEcho($accounts['username']) ." </p>
</td>
<td>
<p>" . $newValidation->safeEcho($accounts['email'])." </p>
</td>
</tr>
";
}
Lets say my table look likes this
<username> <email>
Now i want it to look like this
<username> <email> <total orders>
I was thinking i should use a inner join but how i can do that ?
Greetz

Answer 1

I think you can change your query to:
SELECT user.*, t.cnt FROM user JOIN (SELECT gebruikersnaam, COUNT(*) AS cnt FROM orders GROUP BY gebruikersnaam) t ON user.username = t.gebruikersnaam
With this query you can get users orders but you will skip users without orders, so to get them you can do LEFT JOIN:
SELECT user.*, t.cnt FROM user LEFT JOIN (SELECT gebruikersnaam, COUNT(*) AS cnt FROM orders GROUP BY gebruikersnaam) t ON user.username = t.gebruikersnaam
I suggested that the field for users in table orders is username. And in your question you point that the table is users but in your query table is user. I am using user. If you change your current query with this one you can add in your code:
foreach($adminAccounts as $results){
$accounts['id'] = $account_id;
$accounts['username'] = $results['username'];
$accounts['email'] = $results['email'];
$accounts['total_orders'] = ($results['cnt'] == NULL) ? 0 : $results['cnt']; // orders per user
$accounts['rest'] = $results;
echo "
<tr>
<td>
<p>" . $newValidation->safeEcho($accounts['username']) ." </p>
</td>
<td>
<p>" . $newValidation->safeEcho($accounts['email'])." </p>
</td>
<td>
<p>" . $newValidation->safeEcho($accounts['total_orders'])." </p>
</td>
</tr>
";
}