sqlalchemy.exc.ArgumentError: Mapper mapped class could notassemble any primary key columns for mapped table 'houses'

Question

啟動 API 時出現錯誤。 該錯誤表明該表沒有主鍵。 但是，我確實在數據庫中看到了主鍵。 任何想法可能會發生什么？ 我想也許連接到數據庫可能出錯。 但是，在調試之后，這似乎不是問題。 這是我的代碼：

#!/usr/bin/env python3
  
import connexion
import logging
import os

from flask_sqlalchemy import SQLAlchemy

from swagger_server import encoder, extensions
from swagger_server.tools.config import AppConfig

def main():
    env_name = os.getenv('FLASK_ENV')
    app = connexion.App(__name__, specification_dir='./swagger/')
    app.app.config.from_object(AppConfig[env_name])
    app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://postgres:postgres@127.0.0.1/research'
    app.app.json_encoder = encoder.JSONEncoder
    db = SQLAlchemy(app.app)
    db.init_app(app.app)
    db.Model.metadata.reflect(db.engine)

    # Start the API
    app.add_api('swagger.yaml', arguments={'title': 'House API'})
    app.run(port=8080)
    logging.getLogger('connexion.operation').setLevel('ERROR')

def shutdown_session(exception=None):
    db_session.remove()

if __name__ == '__main__':
    main()

models/house.py 中的 model

# coding: utf-8
  
from __future__ import absolute_import
from datetime import date, datetime  # noqa: F401
import uuid

from typing import List, Dict  # noqa: F401

from swagger_server.models.base_model_ import Model
from swagger_server.extensions import db
from swagger_server import util
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy import Column, DateTime, String, PrimaryKeyConstraint, ForeignKey, Enum, Boolean, Integer, Float, text

Base = declarative_base()

db.UUID = UUID

class House(Model, db.Model):
    """NOTE: This class is auto generated by the swagger code generator program.

    Do not edit the class manually.
    """
    __tablename__ = 'houses'

    """
    Fields of the table
    """
    house_id = db.Column(UUID(as_uuid=True), primary_key=True, server_default=text("uuid_generate_v4()"))
    address = Column(String)

擴展程序.py

"""Extensions module - Set up for additional libraries can go in here."""
from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

錯誤信息：

sqlalchemy.exc.ArgumentError: Mapper mapped class House->houses could not assemble any primary key columns for mapped table 'houses'

和 Postgres 表

-- Table Definition ----------------------------------------------
CREATE TABLE IF NOT EXISTS houses (
  house_id uuid NOT NULL,
  address varchar(256),
  city varchar(128), 
  state varchar(64),
  created_date_time timestamp with time zone DEFAULT (now() at time zone 'utc'),
  updated_date_time timestamp with time zone DEFAULT (now() at time zone 'utc'),
 
  CONSTRAINT "_pk_houses@house_id" PRIMARY KEY (house_id)
);

有什么想法嗎？

Answer 1

我的 class 中有額外的功能干擾了我的 model。 我可以通過將我的 class 腳本編寫為表名來完成這項工作。