Início / coding / Perguntas / 79595094
Accepted
tcgconsolee
Asked: 2025-04-27 21:46:04 +0800 CST

Por que o Flask SQLalchemy está me dando um erro "nenhuma tabela: usuários"?

  • 772
import os
from flask import Flask, render_template, redirect, url_for, request
from flask_login import LoginManager, UserMixin, login_user, current_user, logout_user
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)

@app.route('/')
def index():
    return render_template('index.html')

app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///db.sqlite"
db = SQLAlchemy()
 
login_manager = LoginManager(app)

class Users(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(250), unique=True,
                         nullable=False)
    password = db.Column(db.String(250),
                         nullable=False)
    location = db.Column(db.String(250),
                         nullable=False)
 
db.init_app(app)
app.app_context().push()
with app.app_context():
    db.create_all()



@login_manager.user_loader
def loader_user(user_id):
    return Users.query.get(user_id)

@app.route('/register', methods=["GET", "POST"])
def register():

    if request.method == "POST":
        if not db.session.query(Users).filter_by(username=request.form.get("uname")).count() < 1:
            return render_template("sign_up.html", value = "USER ALREADY EXISTS")
        if request.form.get("uname") == "":
            return render_template("sign_up.html", value = "USERNAME IS BLANK")
        if request.form.get("psw") == "":
            return render_template("sign_up.html", value = "PASSWORD IS BLANK")
        if request.form.get("loc") == "":
            return render_template("sign_up.html", value = "LOCATION IS BLANK")
        user = Users(username=request.form.get("uname"),
                     password=request.form.get("psw"),
                     location=request.form.get("loc"))
    
        db.session.add(user)    
        db.session.commit()
    
    
        return redirect(url_for("login"))

    return render_template("sign_up.html", value ="")


@app.route("/login", methods=["GET", "POST"])
def login():
    if current_user.is_authenticated:
        return redirect(url_for("index", logged_in = True, username = current_user.username))


    if request.method == "POST":
        user = Users.query.filter_by(
            username=request.form.get("uname")).first()
        if not user:
            return render_template("login.html", value = request.form.get("uname"))
    
    
        if user.password == request.form.get("psw"):
            login_user(user)
            return redirect(url_for("index", logged_in = True, username = user.username))
    return render_template("login.html")

if __name__ == "__main__":
    app.secret_key = 'kevin2000'
    app.config['SESSION_TYPE'] = 'filesystem'
    app.run(host ="0.0.0.0", port = 10000, debug=False)

Este é meu código e aqui estou recebendo este erro

Traceback (most recent call last):
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\base.py", line 1964, in _exec_single_context
    self.dialect.do_execute(
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\default.py", line 945, in do_execute
    cursor.execute(statement, parameters)
sqlite3.OperationalError: no such table: users

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\flask\app.py", line 1511, in wsgi_app
    response = self.full_dispatch_request()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\flask\app.py", line 919, in full_dispatch_request
    rv = self.handle_user_exception(e)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\flask\app.py", line 917, in full_dispatch_request
    rv = self.dispatch_request()
         ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\flask\app.py", line 902, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)  # type: ignore[no-any-return]
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "c:\Users\theco\OneDrive\Documents\veil\app.py", line 41, in register
    if not db.session.query(Users).filter_by(username=request.form.get("uname")).count() < 1:
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\orm\query.py", line 3147, in count
    self._legacy_from_self(col).enable_eagerloads(False).scalar()
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\orm\query.py", line 2836, in scalar
    ret = self.one()
          ^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\orm\query.py", line 2809, in one
    return self._iter().one()  # type: ignore
           ^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\orm\query.py", line 2858, in _iter
    result: Union[ScalarResult[_T], Result[_T]] = self.session.execute(
                                                  ^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\orm\session.py", line 2365, in execute
    return self._execute_internal(
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\orm\session.py", line 2251, in _execute_internal
    result: Result[Any] = compile_state_cls.orm_execute_statement(
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\orm\context.py", line 306, in orm_execute_statement
    result = conn.execute(
             ^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\base.py", line 1416, in execute
    return meth(
           ^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\sql\elements.py", line 523, in _execute_on_connection
    return connection._execute_clauseelement(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\base.py", line 1638, in _execute_clauseelement
    ret = self._execute_context(
          ^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\base.py", line 1843, in _execute_context
    return self._exec_single_context(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\base.py", line 1983, in _exec_single_context
    self._handle_dbapi_exception(
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\base.py", line 2352, in _handle_dbapi_exception
    raise sqlalchemy_exception.with_traceback(exc_info[2]) from e
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\base.py", line 1964, in _exec_single_context
    self.dialect.do_execute(
  File "C:\Users\theco\AppData\Local\Packages\PythonSoftwareFoundation.Python.3.12_qbz5n2kfra8p0\LocalCache\local-packages\Python312\site-packages\sqlalchemy\engine\default.py", line 945, in do_execute
    cursor.execute(statement, parameters)
sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) no such table: users
[SQL: SELECT count(*) AS count_1 
FROM (SELECT users.id AS users_id, users.username AS users_username, users.password AS users_password, users.location AS users_location 
FROM users 
WHERE users.username = ?) AS anon_1]
[parameters: ('xdgsdg',)]
(Background on this error at: https://sqlalche.me/e/20/e3q8)

Eu pesquisei em outros lugares, mas só falam que o db.create_all() não está lá. Eu também sou muito novo no Flask, então alguém pode me ajudar, por favor.

Eu também tentei db.drop_all() e depois db.create_all()

isso também não pareceu funcionar

se ajudar, também posso fornecer o sign_up.html de onde o erro está ocorrendo quando envio o formulário

python

1 respostas

  1. Best Answer

    O erro no such column: locationmencionado na sua pergunta é diferente do traceback real, que está mostrando um no such table: userserro. No entanto, eu vejo o problema. Você está inicializando o Flask-SQLAlchemy após definir rotas, mas antes de inicializar o contexto do aplicativo. Você precisa mover suas configurações para o topo, logo após criar o aplicativo Flask, e inicializar o banco de dados com o aplicativo imediatamente.

    Seu código ficará assim:

    app = Flask(__name__)
app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///db.sqlite"
app.secret_key = 'kevin2000' 
app.config['SESSION_TYPE'] = 'filesystem' 

db = SQLAlchemy(app)

class Users(UserMixin, db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(250), unique=True, nullable=False)
    password = db.Column(db.String(250), nullable=False)
    location = db.Column(db.String(250), nullable=False)


login_manager = LoginManager(app)

with app.app_context():
    db.create_all()

@app.route('/')
def index():
    return render_template('index.html')
    
*/ add the remaining routes here
    • 4

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