Question

我有一个如下所示的表格，当我运行查询时，我需要结果是这样的

结果

title | count
----------------
foo   | 3 
bar   | 2

表格

customer_id | title
-------------------
55          | foo
22          | foo
55          | bar <-- duplicate
23          | bar
55          | bar <-- duplicate
23          | foo

更新谢谢大家的快速回复！

Answer 1

诀窍在于计算distinct客户ID，因此您不会为客户55计算双Foo。

如果需要，您也可以按该计数订购结果，或者您可以省略order by条款。

select 
  title, 
  count(DISTINCT customerid) as `count`
from 
  yourTable
group by 
  title
order by 
  `count` desc

Answer 2

这很容易：

select A.title, count(*) as count -- an usual count(*)
from
(select distinct customer_id, title -- this query removes the duplicates
from table) A
group by A.title  -- an usual group by

Answer 3

对于SQL Server，您可以这样做。

select 
    t.title     ,
    count(*)
from your_table as t
group by
    t.title
order by count(*) DESC

SQl - 选择列并对其进行分组

3 个答案: