如何计算MySQL中非唯一的值组合？

Question

我有一张表格，里面有一些遗留数据，我怀疑可能会有些混乱。这是一个多对多的连接表。

LIST_MEMBERSHIPS 
---------------- 
list_id 
address_id 

我想运行一个查询，将统计每个list_id的出现 - address_id对，并显示出发生从最高计数每到最低出现的次数。

我知道它需要涉及COUNT()和GROUP BY，对吧？

Answer 1

select list_id, address_id, count(*) as count 
from LIST_MEMBERSHIPS 
group by 1, 2 
order by 3 desc 

您可能会发现它有用添加

having count > 1 

Answer 2

select count(*), list_id, address_id 
from list_membership 
group by list_id, address_id 
order by count(*) desc