注:
前期的配置安装请参照:
(1)使用MySQL
我们演示如何连接到MySQL服务器的test数据库:
# 使用MySQL
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
########## prepare ##########
# install mysql-connector-python:
# pip3 install mysql-connector-python --allow-external mysql-connector-python
# (或者)pip3 install mysql-connector
import mysql.connector
# change root password to yours:
conn = mysql.connector.connect(user='root', password='password', database='test')
cursor = conn.cursor()
# 创建user表:
cursor.execute('create table user (id varchar(20) primary key, name varchar(20))')
# 插入一行记录,注意MySQL的占位符是%s:
cursor.execute('insert into user (id, name) values (%s, %s)', ('1', 'Michael'))
print('rowcount =', cursor.rowcount)
# 提交事务:
conn.commit()
cursor.close()
# 运行查询:
cursor = conn.cursor()
cursor.execute('select * from user where id = %s', ('1',))
values = cursor.fetchall()
print(values)
# 关闭Cursor和Connection:
cursor.close()
conn.close()
(2)使用SQLAlchemy
利用上次我们在MySQL的test数据库中创建的user表,用SQLAlchemy来试试:
# 使用SQLAlchemy
# 首先通过pip安装SQLAlchemy:
# $ pip install sqlalchemy
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
from sqlalchemy import Column, String, create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
# 创建对象的基类:
Base = declarative_base()
# 定义User对象:
class User(Base):
# 表的名字:
__tablename__ = 'user'
# 表的结构:
id = Column(String(20), primary_key=True)
name = Column(String(20))
# 初始化数据库连接:
engine = create_engine('mysql+mysqlconnector://root:password@localhost:3306/test')
# 创建DBSession类型:
DBSession = sessionmaker(bind=engine)
# 创建session对象:
session = DBSession()
# 创建新User对象:
new_user = User(id='5', name='Bob')
# 添加到session:
session.add(new_user)
# 提交即保存到数据库:
session.commit()
# 关闭session:
session.close()
# 创建Session:
session = DBSession()
# 创建Query查询,filter是where条件,最后调用one()返回唯一行,如果调用all()则返回所有行:
user = session.query(User).filter(User.id=='5').one()
# 打印类型和对象的name属性:
print('type:', type(user))
print('name:', user.name)
# 关闭Session:
session.close()