Flask SQLAlchemy：flask db init 不起作用（错误：没有这样的命令“db”。）

Question

我第一次在 MacOS Sonoma 14.4.1 和 VSCode 上创建 Flask 应用程序，并尝试将 SQLAlchemy 与 sqlite3 用于我的数据库，但是当尝试使用

flask db init

初始化和创建表时，我不断收到以下错误

Usage: flask [OPTIONS] COMMAND [ARGS]...
Try 'flask --help' for help.

Error: No such command 'db'.

我的项目树如下

document_management_system/
|–– backend/
|   |–– pycache/
|   |   |––__init__.cpython-312.pyc
|   |–– app/
|   |   |–– pycache/
|   |       |––__init__.cpython-312.pyc
|   |   |–– __init__.py
|   |   |–– config.py
|   |   |–– models.py
|   |–– venv/
|   |   |–– . . .
|   |–– app.py
|–– frontend/
|   |–– (empty)

pip list

命令的输出是

Package           Version
----------------- -------
alembic           1.13.1
blinker           1.7.0
click             8.1.7
Flask             3.0.3
Flask-CLI         0.4.0
Flask-Migrate     4.0.7
Flask-SQLAlchemy  3.1.1
greenlet          3.0.3
itsdangerous      2.2.0
Jinja2            3.1.3
Mako              1.3.3
MarkupSafe        2.1.5
pip               24.0
SQLAlchemy        2.0.29
typing_extensions 4.11.0
Werkzeug          3.0.2

我的文件如下：

# app.py
from flask import Flask, request, jsonify
from flask_migrate import Migrate
from app.config import Config
from app.models import db, Document

def create_app():
    app = Flask(__name__)
    app.config.from_object(Config)

    db.init_app(app)
    migrate = Migrate(app, db)
    migrate.init_app(app, db)
    
    @app.route('/upload', methods=['POST'])
    def upload_document():
        id=request.form['id']
        name = request.form['name']
        category = request.form['category']
        file_path = request.form['file_path']
        document = Document(id=id, name=name, category=category, file_path=file_path)
        document.save_to_db()
        return jsonify({'message': 'File uploaded successfully'}), 200

    # Document Deletion Endpoint
    @app.route('/delete/<int:document_id>', methods=['DELETE'])
    def delete_document(document_id):
        document = Document.query.get_or_404(document_id)
        document.delete_from_db()
        return jsonify({'message': 'Document deleted successfully'}), 200

    # Search Endpoint
    @app.route('/search')
    def search_documents():
        # Implement search functionality based on query parameters
        # Example: search by document name
        name = request.args.get('name')
        if name:
            documents = Document.query.filter(Document.name.ilike(f'%{name}%')).all()
            return jsonify([document.serialize() for document in documents])
        else:
            return jsonify({'error': 'Missing query parameter "name"'}), 400
    
    @app.route('/')
    def hello():
        return 'Hello, World!'

    return app

if __name__ == '__main__':
    app = create_app()
    app.run(debug=True)

# config.py
import os

basedir = os.path.abspath(os.path.dirname(__file__))

class Config:
    SQLALCHEMY_DATABASE_URI = 'sqlite:///' + os.path.join(basedir, 'db.sqlite3')
    SQLALCHEMY_TRACK_MODIFICATIONS = False

# models.py
from datetime import datetime
from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

class Document(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(128), nullable=False)
    category = db.Column(db.String(64), nullable=False)
    file_path = db.Column(db.String(256), nullable=False)
    upload_date = db.Column(db.DateTime, nullable=False, default=datetime.now(datetime.UTC))
    
    # upload functionality
    def save_to_db(self):
        db.session.add(self)
        db.session.commit()

    # delete functionality
    def delete_from_db(self):
        db.session.delete(self)
        db.session.commit()

我如何完成数据库设置以开始执行 CRUD 操作？

我尝试删除并重新安装我的 venv 文件夹和所有依赖项，并终止终端以及运行

flask --app flaskr init-db

和

pip3 install flask-migrate --upgrade

但这不起作用。我还卸载了系统上的全局 Flask，但仍然没有任何变化。

Answer 1

在

backend

目录中，输入以下命令来启动 Flask shell：

flask shell

导入数据库并创建表：

from app.models import db
db.create_all()

参见 https://flask-sqlalchemy.palletsprojects.com/en/2.x/quickstart/