flask - sqlalchemy.exc.InvalidRequestError : Object '' is already attached to session '2' (this is '3' )

Question

我正在制作一个重置密码的页面，每次我注册一个新帐户并登录时，当我尝试重置密码时，sqlalchemy.exc.InvalidRequestError: Object '<User at 0x10d437eb8>' is already attached to session '2' (this is '3')出现，似乎每次我修改数据库中已经存在的行时，都会出现这个错误。

这是我的代码:

注册 View :

def register():
    form = RegisterForm()
    if form.validate_on_submit():
        data = form.data
        user = User(
            name=data["name"],
            email=data["email"],
            pwd=generate_password_hash(data["pwd"]),
            avatar="user-blue.png",
            uuid=uuid.uuid4().hex
        )
        db.session.add(user)
        db.session.commit()
        return redirect(url_for("home.login"))
    return render_template("home/register.html", form=form)

重置密码 View :

def pwd_reset():
    form = PwdForm()
    if form.validate_on_submit():
        data = form.data
        user = User.query.filter_by(name=session["user"]).first()
        from werkzeug.security import generate_password_hash
        user.pwd = generate_password_hash(data["new_pwd"])
        db.session.add(user) # problem here
        db.session.commit()
        return redirect(url_for("home.success"))
    return render_template("home/pwd_reset.html", form=form)

据我所知，我不能使用 db.session.add在现有行上？如何解决这个问题

Answer 1

您不需要添加 user到数据库 session 。

只需修改预期的字段并提交 session :

def pwd_reset():
    form = PwdForm()
    if form.validate_on_submit():
        data = form.data
        user = User.query.filter_by(name=session["user"]).first()
        from werkzeug.security import generate_password_hash
        user.pwd = generate_password_hash(data["new_pwd"])
        db.session.commit()
        return redirect(url_for("home.success"))
    return render_template("home/pwd_reset.html", form=form)