连接mysql数据库，创建用户模型

from flask import Flask,render_template,request
 2 from flask_sqlalchemy import SQLAlchemy
 3 import config
 4 
 5 app = Flask(__name__)
 6 app.config.from_object(config)
 7 db = SQLAlchemy(app)
 8 
 9 class User(db.Model):
10     __tablename__ = ‘user‘
11     id = db.Column(db.Integer,primary_key=True,autoincrement=True)
12     username = db.Column(db.String(20),nullable=False)
13     password = db.Column(db.String(20),nullable=False)
14 
15 db.create_all()
16 
17 @app.route(‘/‘)
18 def index():
19     return render_template(‘switch切换.html‘)
20 
21 @app.route(‘/login/‘, methods = [‘GET‘,‘POST‘])
22 def login():
23     return render_template(‘login登录.html‘)
24 
25 @app.route(‘/regist/‘, methods = [‘GET‘,‘POST‘])
26 def regist():
27     if request.method == ‘GET‘:
28         return render_template(‘regist注册.html‘)
29     else:
30         pass
31 
32 
33 
34 if __name__ == ‘__main__‘:
35     app.run(debug=True)