Dołącz null wyników w group_concat
Mam dwa takie stoły
profile_answers
+---------+------------+
| id | class_name |
+---------+------------+
| 1 | Class 1 |
| 2 | Class 2 |
| 3 | Class 1 |
+---------+------------+
edukacja
+---------+--------------------+------------+
| id | profile_answers_id | sample |
+---------+--------------------+------------+
| 1 | 1 | 1234 |
| 2 | 1 | 2334 |
| 3 | 1 | 3434 |
+---------+------------+--------------------+
Uruchomiłem zapytanie,
select educations.profile_answer_id, GROUP_CONCAT(educations.sample) from educations
LEFT JOIN profile_answers ON educations.profile_answers_id = profile_answers.id
mam
+--------+--------------------+-------------+
| id | sample |
+---------+--------------------+------------+
| 1 | 1234,2334,3434 |
+---------+------------+--------------------+
Właściwie chcę
+--------+--------------------+-------------+
| id | sample |
+---------+--------------------+------------+
| 1 | 1234,2334,3434 |
| 2 | NULL |
| 3 | NULL |
+---------+------------+--------------------+