通过用户模型，对数据库进行增删改查操作。

增加：
user = 
db.session.add(user)
db.session.commit()

查询：
User.query.filter(User.username == 'mis1114').first()

修改：
user.password = '111111'
db.session.commit()

删除：
db.session.delete(user)
db.session.commit()

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


#db.create_all()

#增加数据
user=User(username = 'shanshan1',password = '111111')
db.session.add(user)
db.session.commit()

#查询数据
user=User.query.filter(user.username == 'shanshan1').first()
print(user.id,user.username,user.password)


#修改数据
user=User.query.filter(user.username == 'shanshan3').first()
user.password = '0000'
db.session.commit()

#删除数据
user=User.query.filter(user.username == 'shanshan3').first()
db.session.delete(user)
db.session.commit()


@app.route('/')
def index():
    return  render_template('shouye.html')
@app.route(   '/manhua/')
def manhua():
    return  render_template('manhua.html')
@app.route(  '/login/')
def login():
    return render_template('denglu.html')
@app.route('/register/')
def register():
    return render_template('zhuce.html')
@app.route('/wenda/')
def wenda():
    return render_template('wenda.html')

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