Question

I’m trying to create a many-many statement but I am having problems with it.
I’m trying to attach multiple music styles to an event, put them in one row, and separate them with a comma.

This is the code I now have:

SELECT a.* FROM music_types AS a, events_music_types AS b WHERE a.id == b.music_type_id AND b.event_id == events.ID

I’m trying to attach it to what I have now:

SELECT
    events.EVENT_NAME, events.start_datetime, events.end_datetime, events.VENUE_LOCATION, events.PARTY_TYPE, events.IMAGE_URL, events.ENTRANCE_PRICE, 
    venues.VENUE_NAME, venues.BEER_PRICE, venues.WINE_PRICE, SPIRITS_PRICE, 
    party_types.PARTYTYPE
FROM events
INNER JOIN venues 
    ON events.VENUE_LOCATION = venues.ID
INNER JOIN party_types
    ON events.PARTY_TYPE = party_types.ID
WHERE start_datetime >= '$DATE_START_SELECTED'
AND end_datetime < '$DATE_END_SELECTED'

And I made it into this:

SELECT
    events.EVENT_NAME, events.start_datetime, events.end_datetime, events.VENUE_LOCATION, events.PARTY_TYPE, events.IMAGE_URL, events.ENTRANCE_PRICE, 
    venues.VENUE_NAME, venues.BEER_PRICE, venues.WINE_PRICE, SPIRITS_PRICE, 
    party_types.PARTYTYPE, 
    a.*
FROM events
INNER JOIN venues 
    ON events.VENUE_LOCATION = venues.ID
INNER JOIN party_types
    ON events.PARTY_TYPE = party_types.ID
INNER JOIN music_types AS a, events_music_types AS b
WHERE start_datetime >= '$DATE_START_SELECTED'
AND end_datetime < '$DATE_END_SELECTED' 
AND a.id == b.music_type_id 
AND b.event_id == events.ID

And got this error:

You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near ‘== b.music_type_id AND b.event_id == events.ID’ at line 14

To be honest, I’m not even sure how I should echo this and split it into commas, can you help me out please? Thanks a lot! 🙂

PS. I added a little visual interpretation of what the relation looks like.

Answer 1

Your equal to comparisons are incorrect:

AND a.id == b.music_type_id

Should be:

AND a.id = b.music_type_id