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.Column(db.String(20),nullable=False)
    password = db.Column(db.String(20), nullable=False)
    nickname = db.Column(db.String(20))

db.create_all()
#user=User(username='mis1234',password='111111')
# db.session.add(user)
# db.session.commit()

 # user1=User(username='mis101',password='110110')
 # db.session.add(user1)
 # db.session.commit()

 # user2=User(username='mis102',password='110110')
 # db.session.add(user2)
 # db.session.commit()

# user=User.query.filter(User.username=='mis1234').first()
# user.password='123456'
# db.session.commit()
# print(user.id,user.password)
# user1=User.query.filter(User.username=='mis101').first()
# user1.password='12345678'
# db.session.commit()
# print(user1.id,user1.password)
# user2= User.query.filter(User.username == 'mis102').first()
# user2.password='1234566623'
# db.session.commit()
# print(user2.id,user2.password)

# user=User.query.filter(User.username=='mis1234').first()
# db.session.delete()
# db.session.commit()
#
# user1=User.query.filter(User.username=='mis101').first()
# db.session.delete()
# db.session.commit()

user2= User.query.filter(User.username == 'mis102').first()
db.session.delete(user2)
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/test?charset=utf8'
SQLALCHEMY_TRACK_MODIFICATIONS = False