为什么我为SQLAlchemy模型中定义的列获取NameError [英] Why do I get NameError for the column that is defined in SQLAlchemy model

问题描述

我正在使用Flask开发REST API.其中一张表的建模如下:

I am developing REST APIs with Flask. One of the tables is modeled as follows:

class AudioSessionModel(db.Model):
    __tablename__ = 'audio_session'
    id = db.Column('audio_session_id', db.Integer, primary_key = True)
    cs_id = db.Column(db.Integer)
    session_id = db.Column(db.Integer)
    facility = db.Column(db.Integer)
    description = db.Column(db.String(400))

    def __init__(self, cs_id, session_id, facility):
        self.cs_id = cs_id
        self.session_id = session_id
        self.facility = facility

在DAO类中定义了业务逻辑:

Business logics are defined in a DAO class:

class AudioSessionDAO(object):
    def update(self, data):
        audio = AudioSessionModel.query.filter(cs_id == data['CSID'], session_id == data['Session'])
        audio.description = data['Desc']
        db.session.commit()
        return audio

在我的端点中为 PUT 请求调用此 upate 函数:

This upate function is called in my endpoint for PUT request:

@api.route('/OperatorAccessment')
class OperatorAssessment(Resource):

    @api.expect(assessment)
    def put(self):
        as_dao = AudioSessionDAO()
        as_dao.update(request.json)  

模型评估看起来像这样:

assessment = api.model('Operator Assessment', {
    'CSID': fields.Integer(required=True, description='Central Station ID'),
    'Session': fields.Integer(required=True, description='Session ID'),
    'Desc': fields.String(description='Description')
})

当我在请求正文中使用以下json测试 PUT 请求时:

When I test the PUT request with the following json in request body:

{
   "CSID": 1,  
   "Session": 1, 
   "Desc": "Siren"
 } 

我遇到以下错误:

  File "C:\Users\xxx_app\model\dao.py", line 63, in update
    audio = AudioSessionModel.query.filter(cs_id == data['CSID'], session_id == data['Session'])
NameError: name 'cs_id' is not defined

显然，已定义 cs_id .为什么我仍然收到此错误?

Apparently, cs_id is defined. Why am I still getting this error?

推荐答案

您必须使用该类的属性，即

You have to use the attributes of the class, i.e.

AudioSessionModel.query.filter(
    AudioSessionModel.cs_id == data['CSID'],
    AudioSessionModel.session_id == data['Session'])

或 filter_by 带有关键字参数的仅使用 = :

Or filter_by with keyword arguments using just =:

AudioSessionModel.query.filter_by(
    cs_id=data['CSID'],
    session_id=data['Session'])

请参见>SQLAlchemy?

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