create sub Array on join instead of new entries - php

Question

I have 4 lectures where each lecture has it's own name:
jbc2014_lezingen
Then for each lecture there will be questions, in this case 2 for each lecture:
jbc2014_vragen
I use this query:
$query = "SELECT * FROM jbc2014_lezingen
INNER JOIN jbc2014_vragen
ON jbc2014_lezingen.id=jbc2014_vragen.lezing_id";
This results in something like:
[0] => Array
(
[id] => 1
[lezing_naam] => lezing 1
[lezing_id] => 1
[vraag] => foobar?
)
[1] => Array
(
[id] => 2
[lezing_naam] => lezing 1
[lezing_id] => 1
[vraag] => foobar?
)
etc.
So the array size is based on the amount of the questions, not the amount of the lectures.
I would like something like:
[0] => Array
(
[id] => 1
[lezing_naam] => lezing 1
[lezing_id] => 1
[questions] Array (
[0] => [vraag] => foobar?
[1] => [vraag] => foobar?
)
)
Where the questions are in an array (vraag means question).
How can this be done?
Later on I need the multiple choice answers in an array inside the questions as well. But I think that won't be hard after having this one fixed.

Answer 1

The closest thing you could do is something like this -
SELECT jbc2014_lezingen.id as lezing_id,
GROUP_CONCAT(vraag) as vraags
FROM jbc2014_lezingen
INNER JOIN jbc2014_vragen
ON jbc2014_lezingen.id=jbc2014_vragen.lezing_i
GROUP BY jbc2014_lezingen.id
and then just get the values with
explode(",",$row['vraags']);
or create another array with something like this
foreach($raw_result as $key => $value){
$new_array[$key]['lezing_id'] = $value['lezing_id'];
$new_array[$key]['vraags'] = explode(",",$value['vraags']);
}