通过用户模型，对数据库进行增删改查操作。

增加：
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)


db.create_all()

user = User(username='1233', password='4566')
db.session.add(user)
db.session.commit()

user = User.query.filter(User.username == '1233').first
db.session.commit()

user = User.query.filter(User.username == '1233').first()
db.session.delete(user)
db.session.commit()


@app.route('/')
def index():
    return render_template("l")


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