Check checkbox from database values - php

Question

I have two tables in a database. In reports I am storing info for reports and in report_roles I am assigning which user can access the report.
reports
+--+-----------+---------------+
|id|report_name|report_filename|
+--+-----------+---------------+
|13|Report 1 |reportname1 |
|14|Report 2 |reportname2 |
|15|Report 3 |reportname3 |
+--+-----------+---------------+
report_roles
+---------+-------+
|report_id|user_id|
+---------+-------+
|14 |1 |
|13 |1 |
|14 |2 |
|13 |2 |
+---------+-------+
I want to display all the reports from table reports with checkboxes and check only those which are added in the report_roles associated with the user id. This is the code I am running:
$id = $_POST['user_id'];
$query = "SELECT * FROM reports LEFT JOIN report_roles ON report_roles.report_id = reports.id";
$sql = mysqli_query($mysqli, $query);
if (!$sql) {
printf("Error: %s\n", mysqli_error($mysqli));
exit();
}
while($row = mysqli_fetch_array($sql, MYSQLI_ASSOC) ) {
if ($row['user_id'] == $id) {
echo "<input type='checkbox' name='" . ($row['id']) . "'" . "id='" . ($row['id']) . "'" . "value='yes'" . ($row['user_id'] == $id ? 'checked' : '') .">";
echo $row['report_name'];
} else {
echo "<input type='checkbox' name='" . ($row['id']) . "'" . "id='" . ($row['id']) . "'" . "value='yes'" . ">";
echo $row['report_name'];
}
}
If $id = 1 I am receiving this:
|checked| Report2 |checked| Report 1 |unchecked| Report2 |unchecked| Report 1 |unchecked| Report3
Which is completely right based on the code I wrote. I cannot figure out how to display all the reports without duplicates from reports table and check only those which are available in report_roles, something like this:
|checked| Report2 |checked| Report 1 |unchecked| Report3
I am sure I have to change my query with the join. Tried to do accomplish this task with two separate queries without joins but with no luck. Hope someone can help.

Answer 1

Actually I was just missing a statement in my query and thanks to Bernd Buffed I realized that I have to add one AND at the end of the query and it should look like this:
$query = "SELECT * FROM reports LEFT JOIN report_roles ON report_roles.report_id = reports.id AND user_id = $id";
Till now I was adding WHERE user_id = $id and was receiving only those reports which exists in report_roles. With the AND I am receiving all reports from reports table and my script can check only those which are in report_roles based on a simple php check.