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(20))

#db.create_all()

#增加
user = User(username ='ll1234',password ='1234',againpass='1234')
db.session.add(user)
db.session.commit()


#查找
# user = User.query.filter(User.username =='ll1234').first()
# user.password ='1234'
# user.againpass='1234'
# print(user.id,user.username,user.password)




#修改
user =User.query.filter(User.username =='aa990').first()
user.password='22365'
print(user.username,user.password)
db.session.commit()



#删除
#user = User.query.filter(User.username =='ll1234').first()
#db.session.delete(user)
#db.session.commit()

@app.route('/')
def hello_world():
    return 'Hello World!'
 
if __name__ == '__main__':
    app.run()