除非指定了行ID，否则Flask/FastAPI SQLite pytest装置将返回None

import pytest
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):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)

@pytest.fixture
def client():
    app.config['TESTING'] = True
    with app.test_client() as client:
        db.create_all()
        yield client
        db.drop_all()

def test_get_user_by_id(client):
    # 创建测试数据
    user = User(username='testuser')
    db.session.add(user)
    db.session.commit()

    # 发送GET请求并断言返回的结果
    response = client.get('/users/1')  # 假设这是获取特定用户的接口
    assert response.status_code == 200
    assert response.json['username'] == 'testuser'

def test_get_all_users(client):
    # 创建测试数据
    user1 = User(username='user1')
    user2 = User(username='user2')
    db.session.add_all([user1, user2])
    db.session.commit()

    # 发送GET请求并断言返回的结果
    response = client.get('/users')
    assert response.status_code == 200
    assert len(response.json) == 2