Как получить SQL запрос с помощью GROUP_CONCAT?

Question

[Евгений]

Дано:
Таблица tasks

|id	|title	|parent_id	
-------------------------------
|1	|One 	|0		
|2	|Two 	|1		
|3	|Three	|1		
|4	|Four	|0		
|5	|Five	|2		
...

Как получить SQL запрос: as subtasks

|id	|title	|parent_id	|subtasks
---------------------------------
|1	|One 	|0		|2,3	
|2	|Two 	|1		|5
|3	|Three	|1		|null
|4	|Four	|0		|null
|5	|Five	|2		|null
...

Comments

[Akina]

JOIN двух копий таблицы. GROUP BY. GROUP_CONCAT().

Answer 1

[Slava Rozhnev]

SELECT tasks.id, tasks.title, tasks.parent_id, GROUP_CONCAT(subtasks.id) subtasks
FROM tasks
LEFT JOIN tasks AS subtasks ON subtasks.parent_id = tasks.id
GROUP BY tasks.id, tasks.title, tasks.parent_id

Comments

[Slava Rozhnev]

ChairfaceChippendale, полностью с Вами согласен.