1. mysql创建数据库
2. 数据库配置信息config.py
3. 建立mysql和app的连接
4. 创建用户模型

from flask import Flaskfrom flask_sqlalchemy import  SQLAlchemyimport configapp = Flask(__name__)app.config.from_object(config)db=SQLAlchemy(app)class User(db.Model):    __tablename__='user'    id=db.Column(db.Integer,primary_key=True,autoincrement=True)    username=db.Column(db.String(20),nullable=False)    password=db.Column(db.String(20),nullable=False)    nickname=db.Column(db.String(20))db.create_all()@app.route('/')def hello_world():    return 'Hello World!'if __name__ == '__main__':    app.run()

　　config.py

SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root:@127.0.1:3306/wgd?charset=utf8'SQLALCHEMY_TRACK_MODIFICATIONS = False