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)

#建立表user
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()

#增加数据
#user = User(username = ‘mis2333‘,password = ‘2333‘)
#user = User(username = ‘lulu‘,password = ‘666666‘)
#db.session.add(user)
#db.session.commit()

#查询数据
#user=User.query.filter(User.username==‘lulu‘).first()
#print(user.username,user.password)

#修改数据
# user=User.query.filter(User.username==‘lulu‘).first()
# user.password=‘666667‘
# print(user.username,user.password)
# db.session.commit()

#删除数据
#user=User.query.filter(User.username==‘mis2333‘).first()
#db.session.delete(user)
#db.session.commit()

@app.route(‘/‘)
def index():
    return render_template(‘index.html‘)

@app.route(‘/login/‘)
def login():
    return render_template(‘login.html‘)

@app.route(‘/regist/‘)
def regist():
    return render_template(‘regist.html‘)


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