python操作MySQL

查询：

from pymysql import *


class JD(object):
    def __init__(self):
        # 连接数据库
        self.conn = connect(host="127.0.0.1",port=3306,database="jing_dong",user="root",password="root",charset="utf8")
        # 创建cursor对象
        self.cursor = self.conn.cursor()

    def __del__(self):
        print("数据库关闭")
        # 关闭cursor
        self.cursor.close()
        # 关闭连接
        self.conn.close()


    def show_all_goods(self,sql):
        """查询所有商品"""
        # 执行sql语句
        self.cursor.execute(sql)
        for temp in self.cursor.fetchall():
            print(temp)

    def show_cates(self,sql):
        """查询分类"""
        self.cursor.execute(sql)
        for temp in self.cursor.fetchall():
            print(temp)

    def show_brands(self,sql):
        """查询品牌"""
        self.cursor.execute(sql)
        for temp in self.cursor.fetchall():
            print(temp)

    @staticmethod
    def print_menu():
        """菜单"""
        print("---京东---")
        print("1.查询所有商品")
        print("2.查询所有商品分类")
        print("3.查询所有商品品牌")
        return input("请输入您需要执行的指令：")

    def run(self):

        while True:
            nums = self.print_menu()
            if nums == "1":
                sql = "select * from goods"
                self.show_all_goods(sql)
            elif nums == "2":
                sql = "select * from goods_cates"
                self.show_cates(sql)
            elif nums == "3":
                sql = "select * from goods_brands"
                self.show_brands(sql)
            elif nums == "q":
                break
            else:
                print("你的输入有误，请重新输入：")


def main():
    # 实例化京东对象
    jd = JD()
    # 运行
    jd.run()


if __name__ == '__main__':
    main()

增删改：

from pymysql import *

def main():
    # 创建Connection连接
    conn = connect(host='localhost',port=3306,database='jing_dong',user='root',password='mysql',charset='utf8')
    # 获得Cursor对象
    cs1 = conn.cursor()
    # 执行insert语句，并返回受影响的行数：添加一条数据
    # 增加
    count = cs1.execute('insert into goods_cates(name) values("硬盘")')
    #打印受影响的行数
    print(count)

    count = cs1.execute('insert into goods_cates(name) values("光盘")')
    print(count)

    # # 更新
    # count = cs1.execute('update goods_cates set name="机械硬盘" where name="硬盘"')
    # # 删除
    # count = cs1.execute('delete from goods_cates where id=6')

    # 提交之前的操作，如果之前已经之执行过多次的execute，那么就都进行提交 确认提交
    conn.commit()
    # 如果发现之前执行的语句有问题 就先别提交 rollback（）回滚 撤销提交
    conn.rollback()

    # 关闭Cursor对象
    cs1.close()
    # 关闭Connection对象
    conn.close()

if __name__ == '__main__':
    main()