Question

我的Django项目中有以下模型：

class Player(models.Model):
    name = models.CharField()

class Team(models.Model):
    name = models.CharField()

class Membership(models.Model):
    player = models.ForeignKey(Player)
    team = models.ForeignKey(Team)
    date_joined = models.DateField()
    date_leaved = models.DateField(blank=True, null=True)

我想在Django级别创建一个可以执行该操作的视图：

CREATE VIEW last_contract_expire AS
SELECT Player.name, MAX(Membership.date_leaved)
FROM player LEFT OUTER JOIN membership ON membership.player.id=player.id
GROUP BY player.id;

Answer 1

Django目前不支持SQL视图（see this ticket）。 Django也不直接支持SQL GROUP BY。无论如何，你可以这样做：

def last_contract_expire():
    return Player.objects.all().annotate(max_date_leaved=Max('membership__date_leaved'))

这将返回所有玩家，每个玩家将拥有name和max_date_leaved属性。希望这有帮助

ORM Django LEFT JOIN + GROUP BY

1 个答案: