来自不同不同表格的sql多个计数

Question

如何获取引用者的所有线索和命中？

表：hits_log

+-----------+----------+ 
| topic  | referer | 
+-----------+----------+ 
| topic0614 | xxxxxxxx | 
| topic0614 | xxxxxxxx | 
| topic0615 | zzzzz | 
| topic0615 | yyyyyy | 
| topic0614 | xxxxxxxx | 
| topic0614 | xxxxxxxx | 
| topic0615 | zzzzz | 
| topic0615 | yyyyyy | 
| topic0614 | yyyyyy | 
| topic0614 | yyyyyy | 
| topic0615 | zzzzz | 
| topic0615 | yyyyyy | 
+-----------+----------+ 

表：leads_log

+-----------+----------+ 
| topic  | referer | 
+-----------+----------+ 
| topic0614 | xxxxxxxx | 
| topic0614 | xxxxxxxx | 
| topic0614 | xxxxxxxx | 
| topic0615 | zzzzz | 
| topic0615 | yyyyyy | 
| topic0614 | xxxxxxxx | 
| topic0615 | zzzzz | 
| topic0614 | yyyyyy | 
+-----------+----------+ 

我想这样 结果如果与主题搜索topic0614

+-----------+----------+------------+ 
| referer | hits  | leads  | 
+-----------+----------+------------+ 
| xxxxxxxx | 4  | 4   | 
| yyyyyy | 2  | 1   | 
+-----------+----------+------------+ 

我曾尝试

SELECT h.referer, COUNT(h.referer) as hits, COUNT(l.referer) as leads FROM `hits_log` h ,`leads_log` l 
WHERE h.topic='topic0614' and h.referer=l.referer 
GROUP BY h.referer 

，但它没有工作

任何一个能帮助我吗？谢谢。

Answer 1

您需要在子查询中单独分组每个表。如果您在主要查询中进行计数，则可以计算导致乘法的交叉乘积的结果。

SELECT h.referer, hits, leads 
FROM (SELECT referer, COUNT(*) AS hits 
     FROM hits_log 
     WHERE topic = 'topic0614' 
     GROUP BY referer) AS h 
JOIN (SELECT referer, COUNT(*) AS leads 
     FROM leads_log 
     GROUP BY referer) AS l 
ON h.referer = l.referer 

DEMO

也许这实际上是你想要的。它限制命中和导致一个特定的主题，并将在任一表中包括零计数的查阅者。

SELECT referer, MAX(hits) AS hits, MAX(leads) AS leads 
FROM (SELECT referer, COUNT(*) AS hits, 0 as leads 
     FROM hits_log 
     WHERE topic = 'topic0614' 
     GROUP BY referer 
     UNION 
     SELECT referer, 0 AS hits, COUNT(*) as leads 
     FROM leads_log 
     WHERE topic = 'topic0614' 
     GROUP BY referer) AS x 
GROUP BY referer 

DEMO