JSON 序列化程序的 StatementError

Question

这里我有简单的休息 API 端点来使用以下模型创建乘客对象，

 class PassengerModel(db.Model):

    __tablename__ = 'passenger'

    ps_id          = db.Column(db.Integer, primary_key=True, autoincrement=True)
    ps_token_id    = db.Column(db.String(120),unique=True, nullable=False)
    passenger_name = db.Column(db.String(50),unique=True, nullable=False)
    passenger_email= db.Column(db.String(120),unique=True, nullable=False)
    prof_pic       = db.Column(db.String(120),unique=True, nullable=False)
    is_ontrip      = db.Column(db.Boolean, nullable=True)
    created        = db.Column(db.DateTime, default=datetime.datetime.utcnow,nullable=True)
    updated        = db.Column(db.DateTime,nullable=True)

和resource.py看起来像这样，


passenger_parser = reqparse.RequestParser()

passenger_parser.add_argument('ps_token_id')
passenger_parser.add_argument('passenger_name')
passenger_parser.add_argument('passenger_email')
passenger_parser.add_argument('prof_pic')
passenger_parser.add_argument('is_ontrip')
passenger_parser.add_argument('created')
passenger_parser.add_argument('updated')

class PassengerRegistration(Resource):
    def post(self):
        data = passenger_parser.parse_args()

        if PassengerModel.find_by_email(data['passenger_email']):
            return {'message': 'User {} already exists'.format(data['passenger_name'])}

        new_passenger = PassengerModel(
            ps_token_id     = data['ps_token_id'],
            passenger_name  = data['passenger_name'],
            passenger_email = data['passenger_email'],
            prof_pic        = data['prof_pic'],
            is_ontrip       = data['is_ontrip']
        )

        try:
            new_passenger.save_to_db()
            return {'message': 'passenger {} created'.format(data['passenger_name'])}
        except Exception as e:
            return {'message': 'Something went wrong', 'error': e}, 500

有一次我尝试用邮递员创建新的乘客对象时出现以下错误，

 {
    "ps_token_id":"1@asdsd",
    "passenger_name":"vAAaA",
    "passenger_email":"vAasd@g.com",
    "prof_pic":"asdasdv",
    "is_ontrip":"False"
}

它returns这个错误，

TypeError: Object of type StatementError is not JSON serializable

对于 is_ontrip 我已经尝试 0 and 1, true, false 带牙套和不带牙套。每次都报上面的错误。

我哪里做错了？

Answer 1

调用 new_passenger.save_to_db() 时出现问题，导致 SqlAlchemy StatementError.

这无法序列化为 JSON，因此您需要提供可序列化的类型，例如字符串：

... 'error': str(e)}, 500

或访问 StatementError 特定属性，添加单独的 except:

...
except StatementError as se:
    return {'message': 'DB error', 'error': str(se), 'statement': se.statement}, 500

JSON 序列化程序的 StatementError

StatementError for JSON serializer

python

flask

flask-sqlalchemy

flask-restful