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 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)

#db.create_all()

# user = User(username = ‘mis9999‘,password = ‘123123123‘)
# db.session.add(user)
# db.session.commit()

# user = User.query.filter(User.username == ‘mis9999‘).first()
# user.password = ‘1231234321‘
# db.session.commit()
# print (user.id,user.password)

# user = User.query.filter(User.username == ‘mis9999‘).first()
# db.session.delete(user)
# db.session.commit()

# user = User(username = ‘mis666‘,password = ‘999666‘)
# db.session.add(user)
# db.session.commit()

# user=User.query.filter(User.username==‘m456123‘).first()


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


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

SQLALCHEMY_DATABASE_URI = ‘mysql+pymysql://root:@127.0.0.1:3306/niub2?charset=utf8‘
SQLALCHEMY_TRACK_MODIFICATIONS = False