flask使用orm连接数据库

逃离我推掉我的手 2022-05-31 08:12 190阅读 0赞

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

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# 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()

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# 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)

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# 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