通过用户模型，对数据库进行增删改查操作

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
import connect

app = Flask(__name__)
app.config.from_object(connect)#app连接数据库

db = SQLAlchemy(app)

class User(db.Model):
    __tablename__ =‘user1‘
    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)
    againpass = db.Column(db.String(20), nullable=False)

#db.create_all()
#增加
user=User(username=‘111‘,password=‘222‘)
db.session.add(user)
db.session.commit()


#查找
user=User.query.filter(User.username==‘two1234‘).first()
print(user.id,user.username,user.password)

#修改
user=User.query.filter(User.username == ‘mis1234‘).first()
user.password = ‘22222‘
db.session.commit()
print(user.id,user.username,user.password)
#删除
user=User.query.filter(User.username==‘two1234‘).first() user.password=‘12345678910‘
db.session.delete(user)
db.session.commit()