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), nullable=False)

#1.db.create_all()

#2.在表中插入一条记录
#user = User(username = 'mis1234',password = '111111', nickname='wkk')
#db.session.add(user)
#db.session.commit()


#3.去表中查询用户名对应的密码和接下来用户输入的密码是否相匹配
#user = User.query.filter(User.username == 'mis1234').first()
#print(user)
#print(user.id,user.username)#输出查找到的用户名的id,密码等.

#4.修改查询到的用户名的密码等
#user = User.query.filter(User.username == 'mis1234').first()
#user.password = '123'
#db.session.commit()

#5.再次插入一条记录
#user = User(username = 'wk',password = '34556', nickname='kk')
#db.session.add(user)
#db.session.commit()

#6.删除一条记录
user = User.query.filter(User.username == 'mis1234').first()
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