Question

So I’m not the best at SQL I have this complicated MySQL query that I’m lost in. The part I don’t understand is, all of the results that come out of the partial query above UNION are multiplied by 8. How is this possible? Why are they being multiplied by 8 and how can I stop it? I also have a few other queries very similar to this one and they all have this same problem. Any ideas on why this could be happening would be greatly appreciated. Thank you!

SELECT best_thrown
    FROM(
        SELECT CASE WHEN rageup_echelon.party_id IS NULL THEN 0 ELSE SUM(CASE WHEN rageup_echelon.echelon_vote = 1 THEN 5 ELSE 0 END) - SUM(CASE WHEN rageup_echelon.echelon_vote = 0 THEN 3 ELSE 0 END) END AS best_thrown
        FROM rageup_parties LEFT JOIN rageup_echelon ON rageup_parties.party_id = rageup_echelon.party_id
                            LEFT JOIN rageup_team_hosts ON rageup_parties.party_team_id = rageup_team_hosts.team_id
        WHERE rageup_team_hosts.team_id = 1 || rageup_team_hosts.team_id = 2 || rageup_team_hosts.team_id = 3
        AND rageup_parties.party_status = 'approved'
        AND rageup_parties.party_invites = 'public'
        AND rageup_team_hosts.user_id = 1
        GROUP BY rageup_parties.party_id
        UNION
        SELECT CASE WHEN rageup_echelon.party_id IS NULL THEN 0 ELSE SUM(CASE WHEN rageup_echelon.echelon_vote = 1 THEN 5 ELSE 0 END) - SUM(CASE WHEN rageup_echelon.echelon_vote = 0 THEN 3 ELSE 0 END) END AS best_thrown
        FROM rageup_parties LEFT JOIN rageup_echelon
        ON rageup_parties.party_id = rageup_echelon.party_id
        WHERE rageup_parties.party_host_id = 1
        AND rageup_parties.party_status = 'approved'
        AND rageup_parties.party_invites = 'public'
        AND rageup_parties.party_team_id = 'user'
        GROUP BY rageup_parties.party_id
        ORDER BY best_thrown DESC
        LIMIT 1
    ) AS T

Answer 1

For debugging, run just the first query without the GROUP BY stuff and look at the underlying rows that are returned.

Also note that you’re using LEFT JOIN from rageup_parties to rageup_team_hosts – making matching team_hosts entries optional – but then requiring team_id to be set to non-NULL values in the WHERE clause. If you know the data is dirty enough to require the LEFT JOIN, move those conditions into the ON clauses for each LEFT JOIN.