sqlalchemy.exc.OperationalError:(sqlite3.OperationalError)没有

Question

我正试图用SQLAlchemy(用Flask(创建一个模型，但我在互联网上找不到解决我问题的方法。

它给我的错误是

sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such column: users.access

但我从文档和教程中看到，初始化列的语法是正确的。

实例.py

from flask import Flask, redirect, url_for, render_template, request, session, flash
from datetime import timedelta
from flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)  # Create an instance of Flask
app.secret_key = "website"
app.config["SQLALCHEMY_DATABASE_URI"] = 'sqlite:///users.sqlite3'
app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
app.permanent_session_lifetime = timedelta(days=4)
db = SQLAlchemy(app)
ACCESS = {
'guest': 0,
'user': 1,
'admin': 2
}
class users(db.Model):
# every row has ID of type integer and it is unique (primary_key)
_id = db.Column("id", db.Integer, primary_key=True)
name = db.Column("name", db.String(100))
email = db.Column("email", db.String(100))
access = db.Column("access", db.Integer)
def __init__(self, name, email, access=ACCESS["user"]):
self.name = name
self.email = email
self.access = access
def is_admin(self):
return self.access == ACCESS["admin"]
def allowed(self, access_level):
return self.access >= access_level

app.register_blueprint(admin, url_prefix="/admin")

当我试图访问数据库的路由(例如/login(时，就会出现错误，该路由在main.py:中定义

from flask import Flask, redirect, url_for, render_template, request, session, flash
import instances
def load_admins(filename='admin_names.txt'):
file = open(filename,'r+')
content = file.read()
lines = content.split("n")
print("ADMINS: ",lines)
return lines
admins = load_admins()

@instances.app.route("/home")#
def home():
return render_template("index.html")
@instances.app.route("/login", methods=["POST", "GET"])
def login():
print("LOGIN FORM: ",request.form)
if request.method == "POST":
session.permanent = True
user = request.form["name"]
session["user"] = user #store data as dict
session["access"] = 1
print(session)
found_user = instances.users.query.filter_by(name=user).first()
if found_user:
session["email"] = found_user.email
if found_user.email in admins:
session["access"]=2
else:
usr = instances.users(user, "",1)
print(usr)
instances.db.session.add(usr)  # add user to database
instances.db.session.commit()
print(session)
flash("Login successful")
print("Session: ",session)
return redirect(url_for("user"))
else:
if "user" in session:
#flash("Already logged in")
print("Session: ", session)
return redirect(url_for("user"))
return render_template("login.html")
if __name__=="__main__":
instances.db.create_all()
instances.app.run(debug=True)

经过多次调试和在线研究，我认为它并没有从"；access=数据库。列("访问"，db.Integer("；出于某种原因。提前谢谢。

Answer 1

没错，access = db.Column("access", db.Integer)还没有更改数据库。有两种方法可以做到这一点。一种是使用db.create_all()方法，该方法查看您定义的模型并创建它们。这对于快速和肮脏的方法来说很好，但在现实世界中非常不鼓励，因为你不知道它做什么，也不能保证你的本地和生产服务器以这种方式拥有相同的模式。

一个更健壮的方法是使用Flask Migrate为您执行此操作。它与Flask和SQLAlchemy很好地集成在一起，即使需要阅读一些内容，它也会让你很好地控制数据库。

Answer 2

import sqlite3
conn = sqlite3.connect('guide.bd') 
c = conn.cursor()

c.execute('''
INSERT INTO Ville (Ville_id, Nom_Ville)
VALUES
(6, 'Marrakech'),
(7, 'FES'),
(8, 'RABAT'),
(9, 'TANGER')

''')
conn.commit()