关于python:sqlAlchemy在包含的循环中生成查询

SQLAlchemy generating query in loop with contains

我正在Flask中构建一个涉及到一些SQLAlchemy的Web应用程序。我有一个函数"get_team()"，这让我很疯狂。

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def get_team(playerlist)
cond = and_(*[Team.users.contains(p) for p in playerlist ])
q = Team.query.filter(cond)
...

我不断地得到错误："attributeError:'unicode'对象没有属性'u sa_instance_state'"。模型如下：

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class Team(db.Model):
__tablename__ = 'teams'

id = db.Column(db.Integer, primary_key=True)
users = association_proxy("user_associations","user", creator=lambda u: Teaming(user=u))

def __repr__(self):
s =""
for u in self.users:
s = s + u.username +","

return"Team {tid}: {users_string}".format(tid = self.id, users_string=s)

class Teaming(db.Model):
__tablename__ = 'teaming'

team_id = db.Column(db.Integer, db.ForeignKey('teams.id'), primary_key=True)
user_id = db.Column(db.Integer, db.ForeignKey('users.id'), primary_key=True)

user = db.relationship("User", backref="team_associations")
team = db.relationship("Team", backref="user_associations")

def __repr__(self):
return"".format(uid = self.user_id, tid = self.team_id)

class User(UserMixin, db.Model):
__tablename__ = 'users'

id = db.Column(db.Integer, primary_key=True)

email = db.Column(db.String(64), unique=True, index=True)
username = db.Column(db.String(64), unique=True, index=True)
password_hash = db.Column(db.String(128))
confirmed = db.Column(db.Boolean, default=False)

teams = association_proxy("team_associations","team", creator = lambda t: Teaming(team=t))

任何指示都将非常感谢！

最可能的原因是playerlist不是User实例的列表，而是一些字符串(可能是名称)。contains只在模型实例上工作。如果要使用其他属性，请使用any。

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def get_team_of_players(playerlist):
cond = and_(*[Team.users.contains(p) for p in playerlist])
q = Team.query.filter(cond)
return q

p1, p2 = db.session.query(User).get(1), db.session.query(User).get(2)
q = get_team_of_players([p1, p2]).all()

def get_team_of_usernames(usernames):
cond = and_(*[Team.users.any(User.username == p) for p in usernames])
q = Team.query.filter(cond)
return q

p1, p2 = 'user1', 'user2'
q = get_team_of_usernames([p1, p2]).all()