mysql - 不同条件的 SQL SELECT COUNT

Question

我有一个包含以下示例数据的表格

   IP          URL
=========   ========
1.1.1.1       aaaa
2.2.2.2       bbbb
1.1.1.1       ffff
1.1.1.1       aaaa
3.3.3.3       ssss
5.5.5.5       aaaa
7.7.7.7       bbbb
4.4.4.4       aaaa
1.1.1.1       aaaa
3.3.3.3       bbbb
5.5.5.5       aaaa

我需要选择这个结果：

 IP        URL    Total count of related IPs     Total count of current IP for current URL  
                             (DESC SORT)
=======   =====  =============================  ===========================================  
1.1.1.1   aaaa                6                                     3  
5.5.5.5   aaaa                6                                     2
4.4.4.4   aaaa                6                                     1
2.2.2.2   bbbb                3                                     1
7.7.7.7   bbbb                3                                     1
3.3.3.3   bbbb                3                                     1
1.1.1.1   ffff                1                                     1
3.3.3.3   ssss                1                                     1

我使用了一些类似以下的查询，但没有成功获得确切的结果：

SELECT ip, url, COUNT(ip) totalip FROM mytable
GROUP BY url ORDER BY totalip DESC

感谢任何帮助

标签： mysqlsqljoinselectcount

Answer 1

对于 MySql 8.0+，您可以使用 COUNT() 窗口函数：

SELECT DISTINCT IP, URL,
       COUNT(*) OVER (PARTITION BY URL) Total_count_of_related_IPs,
       COUNT(*) OVER (PARTITION BY IP, URL) Total_count_of_current_IP_for_current_URL
FROM tablename
ORDER BY Total_count_of_related_IPs DESC

对于以前的版本，使用自联接和聚合：

SELECT t1.IP, t1.URL,
       COUNT(*) Total_count_of_related_IPs,
       SUM(t1.IP = t2.IP) Total_count_of_current_IP_for_current_URL
FROM (SELECT DISTINCT * FROM tablename) t1 INNER JOIN tablename t2
ON t2.URL = t1.URL
GROUP BY t1.IP, t1.URL
ORDER BY Total_count_of_related_IPs DESC

见演示。