如何计算组返回的组的数量？

本文介绍了如何计算组返回的组的数量？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 select count(*) as count from table group by foreign_id order by count

这会返回每个外部标识的匹配数。

This returns a number of matches for each foreign id. However what im looking for is to summarise the results.

所以结果是：

10 results grouping 1 elements 5 results grouping 2 elements 7 results grouping 7 elements

推荐答案

好的，得到了​​。问题的标题比问题本身更好：）

Ok, got it. The title of the question expainls it better than the question itself :)

您需要先知道每个FK出现的次数：

You need to first know how many times each FK appears:

select count(*) as GroupAmount from t1 group by foreign_id

一旦你有了这一点，你必须分组，得到每个项目出现的次数与上述相同的方式。这将导致：

Once you have this, you have to group them to get the amount of times each item appears the same way as above. This will result in:

select GroupAmount, count(*) GroupAmountTimes from ( select count(foreign_id) as GroupAmount from t1 group by foreign_id ) as SubQuery group by GroupAmount

查看操作此处