MySQL: GROUP_CONCAT with LEFT JOIN

Use:

   SELECT t.*,          x.combinedsolutions     FROM TICKETS tLEFT JOIN (SELECT s.ticket_id,                  GROUP_CONCAT(s.soution) AS combinedsolutions             FROM SOLUTIONS s          GROUP BY s.ticket_id) x ON x.ticket_id = t.ticket_id

Alternate:

   SELECT t.*,          (SELECT GROUP_CONCAT(s.soution)             FROM SOLUTIONS s             WHERE s.ticket_id = t.ticket_id) AS combinedsolutions     FROM TICKETS t

You just need to add a GROUP_BY :

SELECT Tickets.*, GROUP_CONCAT(Solutions.solution) AS CombinedSolutions FROM Tickets LEFT JOIN Solutions ON Tickets.id = Solutions.ticket_id GROUP_BY Tickets.id ORDER BY Tickets.id;

I think @Dylan Valade's comment is the simplest answer so I'm posting it as another answer: simply adding a GROUP BY Tickets.id to the OP's SELECT should fix the issue. It fixed my own issue.

However, for databases that are not small the accepted answer, especially if there are any predicates on Tickets.id appears to not involve a total table scan and so while the previous paragraph returns the correct results it appears to be much less efficient in my case.