flask不像django，django有自己的ORM集成实现。flask一般使用sqlalchemy进行集成开发，网上已有flask-sqlchrmy可以直接使用。下面来个入门demo。
安装flask、flask-SQLAlchemy
pip install flask pip install flask-SQLAlchemy
建立三个表的ORM对象，分别是user、post、category。
其中post与category有外键关联。
import datetimefrom flask import Flaskfrom flask_sqlalchemy import SQLAlchemy
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///tmp/test.db'app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = Falsedb = SQLAlchemy(app)class User(db.Model):
id = db.Column(db.Integer, primary_key=True)
username = db.Column(db.String(80), unique=True)
email = db.Column(db.String(120), unique=True) def __init__(self, username, email):
self.username = username
self.email = email def __repr__(self):
return '<User %r>' % self.usernameclass Post(db.Model):
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String(80))
body = db.Column(db.Text)
pub_date = db.Column(db.DateTime)
category_id = db.Column(db.Integer, db.ForeignKey('category.id'))
category = db.relationship('Category', backref=db.backref('posts', lazy='dynamic')) def __init__(self, title, body, category, pub_date=None):
self.title = title
self.body = body if pub_date is None:
pub_date = datetime.datetime.utcnow()
self.pub_date = pub_date
self.category = category def __repr__(self):
return '<Post %r>' % self.titleclass Category(db.Model):
id = db.Column(db.Integer, primary_key=True)
name = db.Column(db.String(50)) def __init__(self, name):
self.name = name def __repr__(self):
return '<Category %r>' % self.name一些基本操作
from demo import db, User, Category, Post#创建数据库与表db.create_all()#创建User对象并插入数据库admin = User('admin', 'admin@example.com')
guest = User('guest', 'guest@example.com')
db.session.add(admin)
db.session.add(guest)
db.session.commit()#查询users = User.query.all()
admin = User.query.filter_by(username='admin').first()#创建Post与Category并插入数据库py = Category('python')
p = Post('Hello python!', 'pytho is pretty cool', py)
db.session.add(py)
db.session.add(p)
db.session.commit()
作者：oshimaRyu
链接：https://www.jianshu.com/p/e289068f2d03