Sql ORM Django左连接+;分组
我的Django项目中有以下模型:Sql ORM Django左连接+;分组,sql,django,group-by,left-join,aggregate-functions,Sql,Django,Group By,Left Join,Aggregate Functions,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_j
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级别创建一个视图,它将执行以下操作:
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;
Django当前不支持SQL视图()。Django也不直接支持SQL
GROUPBY
。无论如何,您可以这样实现:
def last_contract_expire():
return Player.objects.all().annotate(max_date_leaved=Max('membership__date_leaved'))
这将返回所有玩家,每个玩家都有属性
name
和max\u date\u leaved
。希望这有帮助这正是我想要的。谢谢!