py mysql结合面向对象，实现类似超市导购机器的功能【4.商品信息】

py mysql结合面向对象，实现类似超市导购机器的功能（自我总结）

步骤4：

商品信息相关操作实现，主要是各种查询操作

实现代码：

    def run(self):
        while True:
            print('-----商品信息-----')
            print('1.查看所有商品信息')
            print('2.按商品名称搜索')
            print('3.查看价格最高商品信息')
            print('4.查看价格最低商品信息')
            print('5.返回上一级')
            num = input('请输入操作类型：')
            if num == '1':
                # 查看所有商品的信息
                sql = """select g.name,c.name,b.name,g.price from goods as g 
                           inner join goods_cates as c on g.cate_id=c.id 
                           inner join goods_brands as b on g.brand_id=b.id"""
                count = self.cs1.execute(sql)
                print('共计搜索到%s条商品信息' % count)
                goods_info = self.cs1.fetchall()
                for temp in goods_info:
                    t_len = len(temp)
                    for i in range(t_len):
                        if i == t_len - 1:
                            print(temp[i], '元')
                        else:
                            print(temp[i], end=', ')

            elif num == '2':
                # 按商品名称搜索
                find_goodsname = input('请输入要搜索的商品名称：')
                args = '%' + find_goodsname + '%'
                sql = """select g.name,c.name,b.name,g.price from goods as g 
                           inner join goods_cates as c on g.cate_id=c.id 
                           inner join goods_brands as b on g.brand_id=b.id 
                           having g.name like '%s';""" % args
                count = self.cs1.execute(sql)
                print('共计搜索到%s条 %s相关数据' % (count, find_goodsname))
                find_goods_info = self.cs1.fetchall()
                for temp in find_goods_info:
                    t_len = len(temp)
                    for i in range(t_len):
                        if i == t_len - 1:
                            print(temp[i], '元')
                        else:
                            print(temp[i], end=', ')

            elif num == '3':
                # 查看价格最高商品信息
                sql = """select g.name,c.name,b.name,g.price from goods as g 
                                           inner join goods_cates as c on g.cate_id=c.id 
                                           inner join goods_brands as b on g.brand_id=b.id 
                                           having g.price=(select max(price) from goods);"""
                count = self.cs1.execute(sql)
                print('价格最高商品：')
                find_goods_info = self.cs1.fetchall()
                for temp in find_goods_info:
                    t_len = len(temp)
                    for i in range(t_len):
                        if i == t_len - 1:
                            print(temp[i], '元')
                        else:
                            print(temp[i], end=', ')

            elif num == '4':
                # 查看价格最低商品信息
                sql = """select g.name,c.name,b.name,g.price from goods as g 
                                           inner join goods_cates as c on g.cate_id=c.id 
                                           inner join goods_brands as b on g.brand_id=b.id 
                                           having g.price=(select min(price) from goods);"""
                count = self.cs1.execute(sql)
                print('价格最低商品：')
                find_goods_info = self.cs1.fetchall()
                for temp in find_goods_info:
                    t_len = len(temp)
                    for i in range(t_len):
                        if i == t_len - 1:
                            print(temp[i], '元')
                        else:
                            print(temp[i], end=', ')

            elif num == '5':
                break
            else:
                print('操作模块选择错误，请重新输入')