一、数据准备

CREATE TABLE `staff_product` (
  `staffId` bigint NOT NULL COMMENT '员工id',
  `staffName` varchar(255) DEFAULT NULL COMMENT '员工姓名',
  `product_count` int DEFAULT NULL COMMENT '生产的产品数',
  PRIMARY KEY (`staffId`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='员工生产量统计表';

二、排序

1.MySQL版本 >= 5.7

select sp.*,
    case when @prevRank=product_count then @curRank
     when @prevRank := product_count then @curRank := @curRank + 1 
     when product_count<=0 then @curRank := @curRank + 1
      end as cntRank
from staff_product sp,
(select @curRank := 0, @prevRank := NULL) r
order by sp.product_count desc

2.MySQL版本>=8.0

select *,
     dense_rank() over (
        order by product_count desc
    ) cntRank
from staff_product