数据库未在 Flask 项目中初始化

Question

我按照 https://flask.palletsprojects.com/en/2.0.x/tutorial/factory/ 上的教程进行操作并在那里成功创建了项目。然后我尝试将它应用到我的新项目中，但我马上就挂断了。数据库模式似乎在任何时候都没有被读取。在代码的其他地方，我尝试打印表格并得到一个空列表。这是代码中应该发生的相关块。

__init__.py:

import os
from flask import Flask

def create_app(test_config=None):
    app = Flask(__name__, instance_relative_config=True)
    app.config.from_mapping(
        SECRET_KEY='dev',
        DATABASE=os.path.join(app.instance_path, 'projectdb.sqlite')
    )

    if test_config is None:
        app.config.from_pyfile('config.py', silent=True)
    else:
        app.config.from_mapping(test_config)

    try:
        os.makedirs(app.instance_path)
    except OSError:
        pass

    from . import db
    db.init_app(app)

    from . import auth
    app.register_blueprint(auth.bp)
    print("App created")
    return app

db.py:

import sqlite3
import click
from flask import current_app, g
from flask.cli import with_appcontext

def get_db():
    if 'db' not in g:
        g.db = sqlite3.connect(
            current_app.config['DATABASE'],
            detect_types=sqlite3.PARSE_DECLTYPES
        )
        g.db.row_factory = sqlite3.Row

    return g.db

def close_db(e=None):
    db = g.pop('db', None)
    if db is not None:
        db.close()

def init_db():
    db = get_db()

    with current_app.open_resource('schema.sql') as f:
        db.executescript(f.read().decode('utf8'))

@click.command('init-db')
@with_appcontext
def init_db_command():
    init_db()
    click.echo('Initialized the database.')

def init_app(app):
    app.teardown_appcontext(close_db)
    app.cli.add_command(init_db_command)

auth.py:

import functools

from flask import (
    Blueprint, flash, g, redirect, render_template, request, session, url_for
)

from werkzeug.security import check_password_hash, generate_password_hash
from ldmt.db import get_db

bp = Blueprint('auth', __name__, url_prefix='/auth')

@bp.route('/login', methods=('GET', 'POST'))
def login():
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        db = get_db()
        error = None
                                              
        user = db.execute(
            'SELECT * FROM user WHERE username = ?', (username,)
        ).fetchone()

        if user is None:
            error = 'invalid username.'
        elif not check_password_hash(user['password'], password):
            error = 'incorrect password.'

        if error is None:
            session.clear()
            session['user_id'] = user['id']
            return redirect(url_for('index'))

        flash(error)
    return render_template('auth/login.html')

@bp.before_app_request
def load_logged_in_user():
    user_id = session.get('user_id')

    if user_id is None:
        g.user = None
    else:
        g.user = get_db().execute(
            'SELECT * FROM user WHERE id = ?', (user_id,)
        ).fetchone()

@bp.route('/logout')
def logout():
    session.clear()
    return redirect(url_for('auth.login'))

def login_required(view):
    @functools.wraps(view)
    def wrapped_view(**kwargs):
        if g.user is None:
            return redirect(url_for('auth.login'))

        return view(**kwargs)

    return wrapped_view

schema.sql:

DROP TABLE IF EXISTS user;

CREATE TABLE user (
       id INTEGER PRIMARY KEY AUTOINCREMENT,
       username TEXT UNIQUE NOT NULL,
       password TEXT NOT NULL
);

当我尝试登录时出现问题。数据库中没有添加任何内容，所以我预计会出现找不到该用户的错误，但我得到的错误是 sqlite3.OperationalError: no such table: user

我还可以确认 .sqlite 文件已创建但为空。

Answer 1

您在这里为 flask 创建了一个 CLI 命令...

@click.command('init-db')
@with_appcontext
def init_db_command():
    init_db()
    click.echo('Initialized the database.')

您将必须运行命令行中的命令，如下所示...

flask init-db

数据库未在 Flask 项目中初始化

database not initializing in flask project

python

sqlite

flask