mysql - 匹配字段的计数(列)

Question

出于好奇，有没有一种方法可以让我在 2 个或更多表中获取匹配数据的计数。例如，如果我们得到以下 3 个表，

tbl_1-
ip  |isp    |infection
----------------------
1   |aaaa   |malware
2   |bbbb   |malware
3   |cccc   |ddos
3   |cccc   |trojan
4   |dddd   |ddos

tbl_2-
ip  |isp    |infection
----------------------
1   |aaaa   |malware
3   |cccc   |ddos
4   |dddd   |trojan
5   |eeee   |trojan
6   |ffff   |other

tbl_3-
ip  |isp    |infection
----------------------
1   |aaaa   |ddos
6   |ffff   |
2   |bbbb   |other

我能得出如下所示的答案吗？？

Result-
ip  |isp    |infection  |Match Count
------------------------------------
1   |aaaa   |malware    |2      
1   |aaaa   |ddos       |1      
2   |bbbb   |malware    |1
2   |bbbb   |other      |1
3   |cccc   |ddos       |2
3   |cccc   |trojan     |1
4   |dddd   |ddos       |1
4   |dddd   |trojan     |1
5   |eeee   |trojan     |1
6   |ffff   |other      |1
6   |ffff   |           |1

谢谢你:)

Answer 1

您需要使用 UNION ALL(not UNION only)以允许重复

SELECT ip, isp, infection, COUNT(*)
FROM 
(
SELECT ip, isp, infection FROM tbl_1
UNION ALL
SELECT ip, isp, infection FROM tbl_2
UNION ALL
SELECT  ip, isp, infection FROM tbl_3
) x
GROUP BY ip, isp, infection

SQLFiddle Demo