一，安装SQLAlchemy
1,用pip安装
(venv) [liuhongdi@img news]$ pip3 install sqlalchemy2,安装完成后查看已安装的版本:
(venv) [liuhongdi@img news]$ pip3 show sqlalchemy
Name: SQLAlchemy
Version: 2.0.27
Summary: Database Abstraction Library
Home-page: https://www.sqlalchemy.org
Author: Mike Bayer
Author-email: [email protected]
License: MIT
Location: /web/site/python/news/venv/lib/python3.11/site-packages
Requires: greenlet, typing-extensions
Required-by:二，安装pymysql
1,用pip安装pymysql库
(venv) liuhongdi@192 news % pip3 install pymysql 2,查看已安装库的信息
(venv) liuhongdi@192 news % pip3 show pymysql
Name: PyMySQL
Version: 1.1.0
Summary: Pure Python MySQL Driver
Home-page:
Author:
Author-email: Inada Naoki <[email protected]>, Yutaka Matsubara <[email protected]>
License: MIT License
Location: /Users/liuhongdi/python_work/tutorial/news/venv/lib/python3.12/site-packages
Requires:
Required-by:说明：刘宏缔的架构森林—专注it技术的博客，
网址：https://imgtouch.com
本文: https://blog.imgtouch.com/index.php/2024/02/19/python-shi-zhan-yong-sqlalchemy-zuo-orm/
代码: https://github.com/liuhongdi/ 或 https://gitee.com/liuhongdi
说明：作者:刘宏缔 邮箱: [email protected]
三，看一个简单的例子
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from sqlalchemy import Column, Integer, String
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.orm import declarative_base
import os
import sys
# 打印文件的目录路径（文件的上两层目录）
BASE_DIR = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
# 将这个路径添加到环境变量中。
sys.path.append(BASE_DIR)
host = conf_node['host']
port = conf_node['port']
user = conf_node['user']
pswd = conf_node['password']
base = conf_node['database']
char = conf_node['charset']
# 得到数据库实例
db = create_engine('mysql+pymysql://', connect_args={'user': user,
'password': pswd,
'host': host,
'port': 3306,
'database': base,
'charset': char})
# 建立映射关系
Base = declarative_base()
# 定义类
class News(Base):
__tablename__ = 'news' # 设置表明
id = Column(Integer, primary_key=True)
title = Column(String(500))
url = Column(String(500))
# 创建会话
obj_session = sessionmaker(db)
# 打开会话
db_session = obj_session()
# 查询表中所有数据
all_list = db_session.query(News).all()
for obj in all_list:
print("id:", obj.id)
print("title:", obj.title)
print("url:", obj.url)
# 关闭会话
db_session.close()
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运行结果:
(venv) [liuhongdi@img news]$ python3 lib/mysql/connection.py
id: 1
title: 新浪微博
url: https://weibo.com
id: 2
title: 百度
url: https://baidu.com