通过用户模型，对数据库进行增删改查操作。

from flask import Flask,render_template
from flask_sqlalchemy import SQLAlchemy
import config

app = 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)


 db.create_all()


 user=User(username='mis777789',password='g6666')
 db.session.add(user)
 db.session.commit()


 user = User.query.filter(User.username=='mis777789').first
 user.password='0.0.0.0'
 db.session.commit()

user = User.query.filter(User.username=='mis777789').first()
db.session.delete(user)
db.session.commit()

@app.route('/')
def index():
    return render_template("l")



if __name__ == '__main__':
    app.run(debug=True)