Columns auto selecting - mysql

Question

In my fluid structure I have this raw results:
+----------------------------------------------------------------------+
| Results |
+----+----------+-------------+----------+-----------+-----------------+
| id | group_id | question_id | question | answer_id | answer | input |
+----+----------+-------------+----------+-----------+-----------------+
| 1 | 10001 | 1 | How old | 1 | 25 | NULL |
| 2 | 10001 | 2 | What like| 3 | Cola | NULL |
| 3 | 10001 | 2 | What like| 4 | Other | HotDog |
| 4 | 10001 | 3 | City | 5 | NYC | NULL |
| 5 | 10001 | 4 | Name | 7 | Other | Alex |
| 6 | 10002 | 1 | How old | 1 | 25 | NULL |
| 7 | 10002 | 2 | What like| 6 | Candy | NULL |
| 8 | 10002 | 3 | City | 8 | LA | NULL |
| 9 | 10002 | 4 | Name | 7 | Other | Roman |
+----+----------+-------------+----------+-----------+--------+--------+
After transform:
SET #i := 1;
SELECT #i := #i + 1 AS `id`,
GROUP_CONCAT(CASE WHEN question = 'How old' THEN answer ELSE NULL END) AS `How Old`,
GROUP_CONCAT(CASE WHEN question = 'What like' THEN IF(answer='Other', input, answer) ELSE NULL END) AS `What like`,
GROUP_CONCAT(CASE WHEN question = 'City' THEN answer ELSE NULL END) AS `City`,
GROUP_CONCAT(CASE WHEN question = 'Name' THEN IF(answer='Other', input, NULL) ELSE NULL END) AS `Name`
FROM theTable
GROUP BY group_id;
I have this table:
+----+----------+-------------+----------+-----------+
| id | How Old | What like | City | Name |
+----+----------+-------------+----------+-----------+
| 1 | 25 | Cola,HotDog | NYC | Alex |
| 2 | 25 | Candy | LA | Roman |
+----+----------+-------------+----------+-----------+
It is example query, but real query with normal row ids link - works perfectly. But, i have different count of questions with some typical answer variant in other quiez.
What I can put switch of this rules:
GROUP_CONCAT(CASE WHEN question = 'How old' THEN answer ELSE NULL END) AS `How Old`,
GROUP_CONCAT(CASE WHEN question = 'What like' THEN IF(answer='Other', input, answer) ELSE NULL END) AS `What like`,
GROUP_CONCAT(CASE WHEN question = 'City' THEN answer ELSE NULL END) AS `City`,
GROUP_CONCAT(CASE WHEN question = 'Name' THEN IF(answer='Other', input, NULL) ELSE NULL END) AS `Name`
to MySQL cycle or procedure in top answer like as https://dba.stackexchange.com/questions/47902/how-to-transpose-convert-rows-as-columns-in-mysql?
p.s.
Also, I can prepare "select" in PHP, but its too simple =)