Question

我有如下所示的SQL：

select 
count(*), sum(summary.imp), sum(summary.taps) 
from(
   select 
   sum(impressions) as imp, sum(taps) as taps 
   from report 
   where org_id = 1 and report_date between '2019-01-01' and '2019-10-10'
   group by org_id, country, text)
summary;

此查询在MYSQL中创建派生的临时表。有其他解决方法吗？

Answer 1

我已阅读（但尚未测试）MySQL支持多个列，但计数却不同：

select 
  count(distinct org_id, country, text), sum(impressions) as imp, sum(taps) as taps 
from report 
where org_id = 1 and report_date between '2019-01-01' and '2019-10-10'

我想知道这是真的。我也相当有信心这样的事情会起作用：

select 
  count(distinct concat_ws('###', org_id, country, text)), sum(impressions) as imp, sum(taps) as taps 
from report 
where org_id = 1 and report_date between '2019-01-01' and '2019-10-10'

Answer 2

您可以在由org_id，country和text组成的自定义字符串上使用&&。这样可以确保仅计算它们的唯一组合（从而模拟GROUP BY，然后模拟COUNT）。

我使用了任意定界符text。如果您的country或select COUNT(DISTINCT CONCAT(org_id, '&&', country, '&&', text)), sum(impressions) as imp, sum(taps) as taps from report where org_id = 1 and report_date between '2019-01-01' and '2019-10-10'列可以包含此分隔符，则可以使用其他一些不常见的字符组合作为分隔符：

report

为了获得良好的性能，请在(org_id, report_date)表上定义以下组合索引：Worker.class

分组依据汇总

2 个答案: