通过用户模型，对数据库进行增删改查操作。

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


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)
    nickname = db.Column(db.String(50))

#db.create_all()

#增加数据
user=User(username = ‘kyle123‘,password = ‘123456‘)
db.session.add(user)
db.session.commit()

#查询数据
user=User.query.filter(user.username == ‘kyle123‘).first()
print(user.id,user.username,user.password)


#修改数据
user=User.query.filter(user.username == ‘kyle2017‘).first()
user.password = ‘111111‘
db.session.commit()

#删除数据
user=User.query.filter(user.username == ‘kyle2017‘).first()
db.session.delete(user)
db.session.commit()
@app.route(‘/login‘)
def login():
    return render_template(‘login.html‘)

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

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

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

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


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