正文
python3 + flask + sqlalchemy +orm(3):多对多关系
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一篇文章有多个tag，一个tag也可以属于多篇文章，文章和tag存在多对多关系
config.py
DEBUG = True
#dialect+driver://root:1q2w3e4r5t@127.0.0.1:3306/
DIALECT = 'mysql'
DRIVER='pymysql'
USERNAME = 'demo_user'
PASSWORD = 'demo_123'
HOST = '172.16.10.6'
PORT = 3306
DATABASE = 'db_demo1'SQLALCHEMY_DATABASE_URI = "{}+{}://{}:{}@{}:{}/{}?charset=utf8".format(DIALECT,DRIVER,USERNAME,PASSWORD,HOST,PORT,DATABASE)
SQLALCHEMY_TRACK_MODIFICATIONS = False
print(SQLALCHEMY_DATABASE_URI)
app.py
from flask import Flask
import configfrom flask_sqlalchemy import SQLAlchemy
from sqlalchemy.ext.declarative import declarative_baseapp = Flask(__name__)
app.config.from_object(config)db = SQLAlchemy(app)
Base = declarative_base()article_tag = db.Table('article_tag',
db.Column('article_id',db.Integer,db.ForeignKey("article.id"),primary_key=True),
db.Column('tag_id',db.Integer,db.ForeignKey("tag.id"),primary_key=True)
)class Article(db.Model):
__tablename__='article'
id = db.Column(db.Integer,primary_key=True,autoincrement=True)
title = db.Column(db.String(100),nullable=True)
tags = db.relationship('Tag',secondary=article_tag,backref=db.backref('articles'))class Tag(db.Model):
__tablename__='tag'
id = db.Column(db.Integer,primary_key=True,autoincrement=True)
name = db.Column(db.String(100),nullable=True)db.create_all()@app.route('/')
def index():
article1 = Article(title="aaa")
article2 = Article(title="bbb") tag1 = Tag(name='')
tag2 = Tag(name='') article1.tags.append(tag1)
article1.tags.append(tag2)
article2.tags.append(tag1)
article2.tags.append(tag2)
db.session.add(article1)
db.session.add(article2)
db.session.add(tag1)
db.session.add(tag2)
db.session.commit()
return 'index'if __name__ == '__main__':
app.run(debug=True)
