我是一名学生，正在学习如何使用 Flask 和 SQLite3 创建 Web 应用程序。这是我在这里发表的第一篇文章，因此请原谅任何格式或礼仪错误。由于某种原因，每当我尝试登录我的网站时，都会出现以下错误消息：
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such table: user
[SQL: SELECT user.id AS user_id, user.username AS user_username, user.image_file AS user_image_file, user.password AS user_password
FROM user
WHERE user.username = ?
LIMIT ? OFFSET ?]
[parameters: ('admin', 1, 0)]
在数据库中注册和使用其他 sql 表也存在类似的问题，但我认为解决这个问题也能让我深入了解这些问题。
这是我的相关代码（为简洁起见，省略了不相关的代码）：
my init.py（秘密密钥被封锁，因为我知识不够，不知道他们是否以任何方式妥协）：
#<-------- Run this file to launch the site -------->#
#This initializes the base variables that are used in the project
from flask import Flask
from flask_login import LoginManager
from flask_sqlalchemy import SQLAlchemy
#Start Flask
app = Flask(__name__)
#Configure Secret Key for Flask
app.config['SECRET_KEY'] = "XXXX"
#Set SQL to database
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///site_database.db'
#Create a Database variable using SQL ALchemy
db = SQLAlchemy(app)
#Log in Manager instance for user_loader and interface
# with User Class in models.py
login = LoginManager(app)
#Routes stores the python logic that controls the websites,
#Models stores some data structure stuff
from routes import *
from models import *
if __name__ == "__main__":
app.run()
我的 app.py （它创建数据库并填充一些虚拟值，我认为这可能不是最佳实践）
import sqlite3
from __init__ import db
#Create SQL Tables-- 1 for user names and passwords
connect = sqlite3.connect('site_database.db')
cursor = connect.cursor()
print('Database Opened Successfully.')
# Try Block to attempt to open DB, but bounces out if DB already created
try:
print("Attempting to fill database tables...")
cursor.execute("CREATE TABLE user(id INTEGER NOT NULL , username VARCHAR(20), image_file VARCHAR(20), password VARCHAR(20), UNIQUE (username), PRIMARY KEY (id))")
print("Database Created")
except:
print('Database Already Created.')
#Dummy values so we have something in the DB to start
print('Attempting to fill with values...')
cursor.execute("INSERT OR REPLACE INTO user(id, username, image_file, password) VALUES('0001', 'admin', 'default.jpg', 'password')")
print('Filled with user values.\
\nFilled with filler values.')
#Commit the changes and close
connect.commit()
我的表格.py
from flask_wtf import FlaskForm
from flask_wtf.file import FileField, FileAllowed
from wtforms import StringField, DateField, PasswordField, IntegerField, BooleanField, SubmitField, TextAreaField, SelectField
from wtforms.validators import DataRequired, Length, EqualTo, ValidationError
from models import User
from flask_login import current_user, AnonymousUserMixin
#Changes Parameters for Guest Users
class Anonymous(AnonymousUserMixin):
def __init__(self):
self.username = 'Guest'
#Basic login information (includes remember me field)
class LoginForm(FlaskForm):
username = StringField('Username', validators=[DataRequired(), Length(min=2, max =20)])
password = PasswordField('Password', validators=[DataRequired()])
remember = BooleanField('Remember Me')
submit = SubmitField('Sign In!')
我的模型.py
from __init__ import db, login
from flask_login import UserMixin
from sqlalchemy import *
from flask_sqlalchemy import *
class User(db.Model, UserMixin):
id = db.Column(db.Integer, primary_key= True, unique = True)
username = db.Column(db.String(64), index = True, unique = True, nullable = False)
image_file = db.Column(db.String(20), nullable = False, default = 'default.jpg')
password = db.Column(db.String(20), nullable = False)
try:
pets = db.relationship('Pet', backref = 'author_post', lazy = True)
except:
pass
路线.py。该错误似乎来自“user.User.query.filter_by(username = form.username).first()”行
from flask import render_template, url_for, redirect, flash, session, request, abort
from flask_login import login_user, logout_user, current_user, login_required, LoginManager
from __init__ import *
from functions import *
from models import *
from forms import *
import uuid
# Log in using login-manager authentication
@app.route('/login', methods=['GET', 'POST'])
def login():
#Pushes user back to home if logged in
if current_user.is_authenticated:
return redirect(url_for('home'))
form = LoginForm()
#Get form data
form_username = form.username.data
form_password = form.password.data
#Verify if the user input matches user and pass on file,
# pops a warning if not, logs in (with a cookie making it permanent-ish) if succeeds
if form.validate_on_submit():
user = User.query.filter_by(username=form_username).first()
password = user.password
if user is None or password != form_password:
flash("Login Unsuccessful. Please verify your username and password.", "danger")
return redirect(url_for('login'))
login_user(user)
session.permanent = True
return redirect(url_for('login'))
return render_template('login.html', title = 'Login', form = form)
最后是文件夹层次结构：
项目： 烧瓶宠物
--- 实例（文件夹）
------site_database.db（空。我不知道它为什么在这里。它是否可能表明某些东西？）
---静态（文件夹）
------（图像文件夹和 css/js）
---模板（文件夹
------（html。我认为没有必要包含它，但如果需要的话我可以稍后在评论中添加它）
---init.py
---app.py
---forms.py
---函数.py
---模型.py
---routes.py
实例（文件夹）（空）
site_database.db（上面写有 app.py 中的表和值）
学分.txt
需求.txt
我尝试了很多事情，比如弄乱 URI 地址、修复表、了解有关 sqlalchemy 和 sql 的更多信息，以及向我的小组项目合作伙伴寻求帮助。我已经为此苦苦思索了 3-4 个小时，但我不明白我做错了什么（尽管我对 SQL 和 Flask 很陌生，所以我要让自己放松一点） .
任何帮助将不胜感激！
创建表和添加用户的最简单方法是在您的
__init__.pycreate_all()commit()# ...
from models import *
from routes import *
with app.app_context():
db.create_all()
admin = User(
username='admin',
password='password',
)
db.session.add(admin)
db.session.commit()
您还可以使用 flask shell 或 Flask-Migrate 扩展来创建表并添加数据。