Python 炼金术关系问题，

我有postgres db和一些数据，我可以做任何我想做的事情，直到我添加到Employee和EmployeeExperience的关系，然后得到一个错误，如：

InvalidRequestError: One or more mappers failed to initialize - can't proceed with initialization of other mappers. Triggering mapper: 'mapped class EmployeeExperience->employee_experience'. Original exception was: Mapper 'mapped class Employee->employee' has no property 'employee_experience'

我读了很多教程，不理解我做错了什么，任何解决方案都不适合我，请帮助，这是我的代码

import psycopg2
import datetime

# <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< 
from flask import Flask
from flask_bcrypt import Bcrypt
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = "postgres://postgres:postgres@localhost:5433/db_name"
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True
db = SQLAlchemy()
db.init_app(app)
flask_bcrypt = Bcrypt()
flask_bcrypt.init_app(app)
app.app_context().push()
# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


# <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< models
class Employee(db.Model):
    __tablename__ = "employee"
    
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    surname = db.Column(db.String(200))
    first_name = db.Column(db.String(200))
    birth_date = db.Column(db.Date)
    email = db.Column(db.String(300), unique=True)
    city = db.Column(db.String(200))
    latitude = db.Column(db.Float)
    longitude = db.Column(db.Float)
    male = db.Column(db.Integer)
    registered_on = db.Column(db.DateTime)
    active = db.Column(db.Integer)
    _password = db.Column(db.String(400))
    
    employee_experience = db.relationship("EmployeeExperience", back_populates="employee")
    
    
class EmployeeExperience(db.Model):
    __tablename__ = "employee_experience"
    
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    position = db.Column(db.String(300))
    company = db.Column(db.String(200))
    city = db.Column(db.String(200))
    description = db.Column(db.Text)
    desc_raw = db.Column(db.Text)
    
    employee_id = db.Column(db.Integer, db.ForeignKey('employee.id'))
    employee = db.relationship("Employee", back_populates="employee_experience")       
# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

emp = Employee.query.first()

导入psycopg2
导入日期时间
# >
# >
emp=Employee.query.first（）

'mapped class Employee->Employee'没有属性“Employee\u experience”

---

错误原因已明确说明。您尚未在员工模型上定义

Employee_experience

属性

我认为数据库表中缺少主键会导致问题