无法测试简单的 sqlalchemy 模型数据类："Mapper mapped class could not assemble any primary key columns for mapped table"

Question

我有一个简单的 Python 脚本 (models.py) 来创建 Flask-SQLAlchemy 应用程序和一个简单的 sqlalchemy 数据类 (reference here)，如下所示：

from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = "sqlite:///test.db"
db = SQLAlchemy(app)

class User(db.Model):

    __tablename__ = 'user'

    user_id: db.Column(db.Integer, primary_key=True)
    user_url: db.Column(db.String(2083), unique=True, nullable=False)
    username: db.Column(db.String(80), unique=True, nullable=False)
    avatar_url: db.Column(db.String(2083), unique=True, nullable=False)

然后我按照从 here 创建 Flask-SQLAlchemy 应用程序的示例编写了一个非常简单的 pytest 脚本，如下所示：

import pytest

from models import User
from models import db

def test_basic():

    db.create_all()

    u1 = User(1, "http://testuserurl", "charliebrown", "http://avatarurl")

    assert u1.user_id == 1
    assert u1.user_url == "http://testuserurl"
    assert u1.username == "charliebrown"
    assert u1.avatar_url == "http://avatarurl"

此测试在“from models import User”行立即失败并显示消息：

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

我不明白这条消息（特别是考虑到我确实在 User 中指定了 primary_key）。有什么帮助吗？

Answer 1

尝试使用 = 而不是 :

像这样：

class User(db.Model):

    __tablename__ = 'user'

    user_id = db.Column(db.Integer, primary_key=True)
    user_url = db.Column(db.String(2083), unique=True, nullable=False)
    username = db.Column(db.String(80), unique=True, nullable=False)
    avatar_url = db.Column(db.String(2083), unique=True, nullable=False)

无法测试简单的 sqlalchemy 模型数据类："Mapper mapped class could not assemble any primary key columns for mapped table"

Cannot test simple sqlalchemy model dataclass: "Mapper mapped class could not assemble any primary key columns for mapped table"

python

sqlalchemy

flask-sqlalchemy