Re: Need help with a query

[Peter Brawley]

I adjusted the Select expressions to clarify what's going on. Your two Joins and your Where conditions impose overlapping logic--it's a belt-and-suspenders query, testing both market category IDs and names, producing skew. I think your requirement is met by a simpler query:

select
  e.id, e.title, e.event_categories as cats, e.event_category_1 as cat1, e.event_category_2 as cat2, e.date_from, 
  c.id, c.category_name
from event as e
join event_category as c on c.id in(e.event_category_1, e.event_category_2)
where c.id=69                             -- TEST CAT ID RATHER THAN NAME
  and e.title like '%market%'             -- IS THIS NECESSARY?
  and left(e.date_from,7)='2017-07'       -- FASTER THAN FUNC CALLS
order by date_from ;
+------+-----------------------------+------+------+------+------------+----+---------------+
| id   | title                       | cats | cat1 | cat2 | date_from  | id | category_name |
+------+-----------------------------+------+------+------+------------+----+---------------+
| 9316 | Summer Arts & Crafts Market | 0    |   50 |   69 | 2017-07-22 | 69 | Markets       |
| 9478 | York River Art Market       | 0    |   69 |   32 | 2017-07-29 | 69 | Markets       |
+------+-----------------------------+------+------+------+------------+----+---------------+