SQL计数具有相等的未知值

Question

我有一张桌子：

ID | domain       | address             | downloads
====================================================
 1 | example.com  | example.com/siteA   | 1
 2 | example.com  | example.com/siteB   | 2
 3 | example.com  | sub.example.com     | 1
 4 | example.com  | sub.example.com/dir | 2
 5 | foobar.com   | foobar.com/site123  | 1
 6 | foobar.com   | foobar.com/site     | 2
 ...

现在我想知道一个域名有多少“下载”

domain      | downloads
=======================
example.com | 6
foobar.com  | 3

我的陈述目前是

SELECT domain, COUNT(downloads) as downloads FROM table GROUP BY domain

但这会（当然）返回

domain      | downloads
=======================
example.com | 4
foobar.com  | 2

请注意我不知道域名所以我不能使用条件！

Answer 1

使用SUM代替COUNT：

SELECT domain, SUM(downloads) as downloads 
FROM table 
GROUP BY domain

Answer 2

您可以使用以下总和

select domain,sum(downloads) from tableA group by domain