php - 选择 3 件销量较高的商品

Question

我想用这是我的表格选择 3 个最大的销售记录

CREATE TABLE IF NOT EXISTS `contas` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `id_service` int(11) DEFAULT NULL,
  `data` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=28 ;

'id_service'是主列，销售额越多，添加相同'id_service'的记录越多。

那么我该如何在不使用 PHP 的情况下按降序进行选择呢？

我试过了

select id_service, count(*) as id_service
from vendas WHERE id_service is not null
group by id_service order by id_service desc LIMIT 3

Answer 1

您已将两列别名为相同的名称。难怪查询很困惑。试试这个:

select id_service, count(*) as cnt
from vendas WHERE id_service is not null
group by id_service
order by cnt desc
LIMIT 3;