sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) 没有这样的表：用户

Question

i have been getting this error sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such table: user but i dont know why since i created my database at the good directory by the command sqlite3 database.db and .tables .I tried db.create_all() but if it is before the declaration of db it of course not work but if i put it after it does not change anything

I have an other problem which is that db."" is always marked as an error. I tried to install pylint-flask and loading it in the settings. It worked for around 5 mins then the errors are back again ( Instance of 'SQLAlchemy' has no 'Column' memberpylint(no-member) )

from flask import Flask, render_template, redirect, url_for
from flask_bootstrap import Bootstrap
from flask_wtf import FlaskForm 
from wtforms import StringField, PasswordField, BooleanField
from wtforms.validators import InputRequired, Email, Length
from flask_sqlalchemy  import SQLAlchemy
from werkzeug.security import generate_password_hash, check_password_hash
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user, current_user


app = Flask(__name__)
app.config['SECRET_KEY'] = 'Thisissupposedtobesecret!'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///sqlite-tools-win32-x86-3290000/database.db'
bootstrap = Bootstrap(app)
db = SQLAlchemy(app)
login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = 'login'

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(15), unique=True)
    email = db.Column(db.String(50), unique=True)
    password = db.Column(db.String(80))

@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))

class LoginForm(FlaskForm):
    username = StringField('username', validators=[InputRequired(), Length(min=4, max=15)])
    password = PasswordField('password', validators=[InputRequired(), Length(min=8, max=80)])
    remember = BooleanField('remember me')

class RegisterForm(FlaskForm):
    email = StringField('email', validators=[InputRequired(), Email(message='Invalid email'), Length(max=50)])
    username = StringField('username', validators=[InputRequired(), Length(min=4, max=15)])
    password = PasswordField('password', validators=[InputRequired(), Length(min=8, max=80)])

Answer 1

after defining your Model you need to call create_all() and commit() to update the changes to the database.

for example..

class User(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(15), unique=True)
    email = db.Column(db.String(50), unique=True)
    password = db.Column(db.String(80))

db.create_all()
db.session.commit()