問(wèn)題描述

#!/usr/bin/python#coding=utf-8from flask import Flaskfrom flask_sqlalchemy import SQLAlchemyapp = Flask(__name__)db = SQLAlchemy(app)class News(db.Model): ''' 新聞模型 ''' __tablename__ = ’news’ id = db.Column(db.Integer, primary_key=True) title = db.Column(db.String(200), nullable=False) content = db.Column(db.String(2000), nullable=False) is_valid = db.Column(db.Boolean, default=True) created_at = db.Column(db.DateTime) updated_at = db.Column(db.DateTime) comments = db.relationship(’Comments’, backref=’news’,lazy=’dynamic’) def __repr__(self):return ’<News %r>’ % self.titleclass Comments(db.Model): ''' 新聞評(píng)論 ''' id = db.Column(db.Integer, primary_key=True) content = db.Column(db.String(2000), nullable=False) is_valid = db.Column(db.Boolean, default=True) created_at = db.Column(db.DateTime) updated_at = db.Column(db.DateTime) new_id = db.Column(db.Integer, db.ForeignKey(’news.id’)) def __repr__(self):return ’<News %r>’ % self.contentapp.config[’SQLALCHEMY_DATABASE_URI’] = ’mysql://root:123456@127.0.0.1/flask_test’if __name__ == ’__main__’: app.run(debug=True)

打算學(xué)習(xí)創(chuàng)建數(shù)據(jù)庫(kù)的，但是提示報(bào)錯(cuò)，

>>> from test_orm import dbD:mycodesvirtualflask-testlibsite-packagesflask_sqlalchemy__init__.py:819: UserWarning: SQLALCHEMY_DATABASE_URI not set. Defaulting to 'sqlite:///:memory:'. ’SQLALCHEMY_DATABASE_URI not set. Defaulting to ’>>>

我去看了一下源碼

if ’SQLALCHEMY_DATABASE_URI’ not in app.config: warnings.warn(’SQLALCHEMY_DATABASE_URI not set. Defaulting to ’’'sqlite:///:memory:'.’ )

上面說(shuō)。。。SQLALCHEMY_DATABASE_URI不在app.config里面。。。但是我上面的編碼。。確實(shí)在這個(gè)里面。。我崩潰。。。求助大神們。。。哪出錯(cuò)了。。

問(wèn)題解答

找到問(wèn)題點(diǎn)了，第一個(gè)app.config 要在 db = SQLAlchemy(app) 之前第二個(gè)在python3中的url使用是mysql+pymysql://

db = SQLAlchemy(app)app.config[’SQLALCHEMY_DATABASE_URI’] = ’mysql://root:123456@127.0.0.1/flask_test’

將這兩句調(diào)換順序，應(yīng)該是需要在初始化 db 前設(shè)置URI

另 URI 格式是不是有問(wèn)題，官網(wǎng)文檔