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
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.Colum(db.String(20),nullable=False)
    password=db.Colum(db.String(20),nullable=False)
    nickname=db.Colum(db.String(20))
#db.create_all()

 user=User.query.filter(User.username=='mis1114').first()
 user.password='123456'
 db.session.commit()
 print(user.id,user.password)

user=User(username='mis1114')
db.session.add(user)
db.session.commit()
user.password = '111111'
db.session.commit()

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

@app.route('/')
def hello_world():
    return 'Hello World!'


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

SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root:@127.0.0.1:3306/mis_db?charset=utf8'
SQLALCHEMY_TRACK_MODIFICATIONS = False