flask使用orm连接数据库

版权声明：本文为博主原创文章，如需转载请注明出处，谢谢。 https://blog.csdn.net/qq_38542085/article/details/79318635

注：使用前请安装flask_sqlalchemy包，由于python-mysql不适用于python3.6，所以我们使用pymysql进行替代

---

1.flask的app文件中输入以下代码

(文件名为：learn_flask_mysql_orm.py)
from flask import Flask
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config["SQLALCHEMY_DATABASE_URI"]="mysql+pymysql://root:@127.0.0.1:3306/learn_flask_mysql"
#注：请勿忘记添加'+pymysql'，否则将会出现没有安装mysqldb的报错

db = SQLAlchemy(app)


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


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

---

2.在flask文件夹中新建一个models.py文件，并输入以下代码

from learn_flask_mysql_orm import db

class User(db.Model):
    __tablename__ = 'user'
    user_id = db.Column(db.INT,primary_key=True)
    user_name = db.Column(db.TEXT)

    def __init__(self,user_id,user_name):
        self.user_id = user_id
        self.user_name = user_name

    def __str__(self):
        return "id:{}    name:{}".format(self.user_id,self.user_name)

---

3.在flask中新建一个manage.py文件，输入以下代码

from flask_script import Manager
from models import User
from learn_flask_mysql_orm import app,db

manager = Manager(app)

@manager.command
def save():
    user = User(11,'zhangjia11')
    db.session.add(user)
    db.session.commit()

@manager.command
def query_all():
    users = User.query.all()
    for user in users:
        print(user)

if __name__ == "__main__":
    manager.run()

之后使用python manage.py save即可保存数据，使用python manage.py qurey_all即可查询数据