如何在汇总后排序而不是拆分分组？答案

【问题标题】：How to order by after rollup and not split grouping?如何在汇总后排序而不是拆分分组？
【发布时间】：2018-11-22 16:20:04
【问题描述】：

我使用汇总，我想按最佳年份排序（按利润而不是按字母顺序）而不是拆分年份组。
每年按最佳产品排序（按利润不按字母顺序排列）且不拆分等。

我想要这样的东西：

但我只有这个：

DROP TABLE IF EXISTS abc;
CREATE TABLE abc(year  text,
                      country text, product text, profit integer);

  INSERT INTO abc VALUES ('2016', 'USA', 'Phone', 3000);
  INSERT INTO abc VALUES ('2016', 'USA', 'TV', 1000);
  INSERT INTO abc VALUES ('2016', 'UK', 'TV', 2000);
  INSERT INTO abc VALUES ('2016', 'UK', 'Phone', 1000);
  INSERT INTO abc VALUES ('2015', 'USA', 'TV', 1500);
  INSERT INTO abc VALUES ('2015', 'USA', 'Phone', 1000);
  INSERT INTO abc VALUES ('2015', 'UK', 'Phone', 900);
  INSERT INTO abc VALUES ('2015', 'UK', 'TV', 600);
  INSERT INTO abc VALUES ('2014', 'USA', 'Phone', 1500);
  INSERT INTO abc VALUES ('2014', 'USA', 'TV', 1000);
  INSERT INTO abc VALUES ('2014', 'UK', 'Phone', 1500);
  INSERT INTO abc VALUES ('2014', 'UK', 'TV', 2000);

with data as
(
SELECT year, country, product, profit from abc
  )
 select l.year as year, l.country as country, l.product as product,
  sum(l.profit) as profit
 from data l 
group by rollup(year, country, product)
ORDER BY 
CASE WHEN year IS NULL THEN 1 ELSE 0 END, year

当我按 sum(l.profit) 排序时，它会拆分年份。

【问题讨论】：

删除order by。我认为它会将结果按您想要的顺序排列。

标签： sql postgresql rollup

【解决方案1】：

在 order by 子句中添加更多内容：

DROP TABLE IF EXISTS abc;
CREATE TABLE abc(year  text,
                  country text, product text, profit integer);

  INSERT INTO abc VALUES ('2016', 'USA', 'Phone', 3000);
  INSERT INTO abc VALUES ('2016', 'USA', 'TV', 1000);
  INSERT INTO abc VALUES ('2016', 'UK', 'TV', 2000);
  INSERT INTO abc VALUES ('2016', 'UK', 'Phone', 1000);
  INSERT INTO abc VALUES ('2015', 'USA', 'TV', 1500);
  INSERT INTO abc VALUES ('2015', 'USA', 'Phone', 1000);
  INSERT INTO abc VALUES ('2015', 'UK', 'Phone', 900);
  INSERT INTO abc VALUES ('2015', 'UK', 'TV', 600);
  INSERT INTO abc VALUES ('2014', 'USA', 'Phone', 1500);
  INSERT INTO abc VALUES ('2014', 'USA', 'TV', 1000);
  INSERT INTO abc VALUES ('2014', 'UK', 'Phone', 1500);
  INSERT INTO abc VALUES ('2014', 'UK', 'TV', 2000);

with data as
(
SELECT year, country, product, profit from abc
  )
 select l.year as year, l.country as country, l.product as product,
  sum(l.profit) as profit
 from data l 
group by rollup(year, country, product)
ORDER BY 
CASE WHEN year IS NULL THEN 1 ELSE 0 END,
year,
case when product is NULL THEN 1 else 0 end,
profit desc

【讨论】：