SQL Column result with comma and colon to PHP Array - php

Question

I have a sql query that, for each result returns a string like 1:One, 2:Two, 3:Three.
Now I want to convert each one of these strings to a PHP array like this:
Array(
1: One,
2: Two,
3: Three
)
I know that I could do that with one explode function inside another one but, isn't that too much overkill if I have 500+ results on the mysql query? Is there any better way to get something like that?
Here is a sample of the mysql code that creates something like the string result that I gave:
GROUP_CONCAT(DISTINCT cast(concat(cast(number.id AS char),': ',number.name) AS char) order by number.id SEPARATOR ', ') AS all_active_numbers
EDIT
So here's an example of 2 possible returning rows from mysql:
|-----------------------------------------------------------------------|
| id | all_groups | groups_assigned |
| 1 | 1:Team A, 2:Team B, 3:Team C | 1:Team A |
| 2 | 1:Team A, 2:Team B, 3:Team C | 2:Team B, 3:Team C |
|-----------------------------------------------------------------------|
What I want to know is the best way to transform the strings of all_groups and groups_assigned of each row, into a PHP array. As I said, I know I could do it using 2 explode function (one inside another using foreach loops) but what if my query returns 500+ results? This seems like a big overkill for the server to compute explode's for each one of the 500+ rows.
Just to clarify, all_groups is something like the groups that are available for a person and groups_assigned is the groups where the person is registered from the available all_groups.
Another possibility is maybe divide this into 3 different queries?

Answer 1

Just explode based off of your colon, otherwise, form your query to provide the KEY and VALUE's separately.
PHP example (untested, example only):
$result = $pdo->query($query);
$myArray = array();
while($row = $result->fetchAll(PDO::FETCH_ASSOC)) {
$myGroup = explode(": ", $row['all_active_numbers']);
$myArray[][$myGroup[0]] = $myGroup[1];
}
var_dump($myArray);