Question

我正在ubuntu中使用python学习Rest-API。我想使用SQLAlchemy将数据存储到SQLite数据库中。这是我的密码

BookModel.py

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
import json
from settings import app

db=SQLAlchemy(app)

class Book(db.Model):
    __tablename__='books'

我该怎么办？

    id = db.Column(db.Integer,primary_key=True)
    name = db.Column(db.String(80),nullable=False)
    price = db.Column(db.Float,nullable=False)
    isbn =db.Column(db.Integer)

    def add_book(_name,_price,_isbn):
        new_book=Book(name=_name,price=_price,isbn=_isbn)
        db.Session.add(new_book)
        db.Session.commit()


    def get_all_books(self):
        return Book.query.all()


    def __repr__(self):
        book_object = {'name':self.name,
                       'price':self.price,
                       'isbn':self.isbn}
        return json.dump(book_object)

settings.py

import os
from flask import Flask
app = Flask(__name__)

basedir = os.path.abspath(os.path.dirname(__file__))
app.config['SQLALCHEMY_DATABASE_URI']='sqlite:///' + os.path.join(basedir, 'app.db')
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False

我使用python中的波纹管命令创建数据库，并且可以正常工作。

>>> from BookModel import db
>>> db.create_all()

接下来，我使用以下命令测试add_book（）方法。

>>> from BookModel import *
>>> Book.add_book("ss",55.6,556)

但是PyCharm向我显示以下错误。

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/momo/Projects/flask_rest_aPI /BookModel.py", line 18, in add_book
    db.Session.add(new_book)
TypeError: add() missing 1 required positional argument: 'instance'

Answer 1

Route::redirect('/', '/en'); Route::get('email/verify', 'Auth\VerificationController@show')->name('verification.notice'); Route::get('email/verify/{id}/{hash}', 'Auth\VerificationController@verify')->name('verification.verify'); Route::get('email/resend', 'Auth\VerificationController@resend')->name('verification.resend'); Route::group([ "prefix" => '{language}', 'where' => ['language' => '(en||bg)'], ], function () { //Auth routes Auth::routes(); //Returns to home Route::get('/', 'HomeController@index')->name('home'); //Handles the faq routes Route::resource('faq', 'FaqController'); }); Route::get('password/reset/{token}', 'Auth\ResetPasswordController@showResetForm')->name('password.reset'); Route::post('password/reset', 'Auth\ResetPasswordController@reset')->name('password.update'); });必须小写。

尝试

db.session

Answer 2

在您的BookModel中：

您拥有的功能add_book：

    db.Session.add(new_book)
    db.Session.commit()

应为：

    db.session.add(new_book)
    db.session.commit()

并且add_book和get_all_books函数应该是classmethod：

    @classmethod
    def add_book(cls, _name, _price, _isbn):
        new_book=cls(name=_name,price=_price,isbn=_isbn)
        db.session.add(new_book)
        db.session.commit()


    @classmethod
    def get_all_books(cls):
        return cls.query.all()

TypeError：add（）缺少1个必需的位置参数：'instance'

2 个答案: