Как сделать два запроса JOIN из одной таблицы в Vapor 3, используя Fluent?

@arema, я пытался воспроизвести ваш вариант использования, и у меня была похожая проблема с Fluent. Я сообщил о проблеме на github Fluent: https://github.com/vapor/fluent/issues/563

Вот обходной путь, но это далеко не элегантно.

// Requires conforming `Match` to hashable, Equatable.
func getMatches2Handler(_ req: Request) throws -> Future<[MatchObjects]> {
    return map(
        to: [MatchObjects].self,
        Match.query(on: req).join(\Team.id, to: \Match.homeTeamID).alsoDecode(Team.self).all(),
        Match.query(on: req).join(\Team.id, to: \Match.awayTeamID).alsoDecode(Team.self).all()
    ) { homeTuples, awayTuples in
        let homeDictionary = homeTuples.toDictionary()
        let awayDictionary = awayTuples.toDictionary()
        var matchObjectsArray: [MatchObjects] = []
        matchObjectsArray.reserveCapacity(homeDictionary.count)
        for (match, homeTeam) in homeDictionary {
            let awayTeam = awayDictionary[match]!
            matchObjectsArray.append(MatchObjects(match: match, homeTeam: homeTeam, awayTeam: awayTeam))
        }
        return matchObjectsArray
    }
}

//...

extension Array {
    func toDictionary<K,V>() -> [K:V] where Iterator.Element == (K,V) {
        return self.reduce([:]) {
            var dict:[K:V] = $0
            dict[$1.0] = $1.1
            return dict
        }
    }
}