MySQL：没有像组中那样的字符串？

Question

我的表中有两列：VisitorID 和 URL。

对于访问者进行的每个页面视图，表中都存在一个条目。我想查看每个访问者的总访问次数，其中访问者组中没有一个 URL 类似于“%page=checkout%”。

我想它是这样的：

SELECT *, COUNT(*) AS TotalVisits
FROM `VisitorLog`
GROUP BY VisitorID
HAVING `URL` NOT IN (SELECT * FROM ?? WHERE `URL` LIKE "%page=checkout%")

但我不完全理解 HAVING 子句如何与子查询一起使用，如果我需要子查询，等等？又如何让自己变得消极呢？

任何能解释答案的人都会得到奖励积分，这样我下次就可以自己做！

谢谢，

尼克

Answer 1

SELECT *, COUNT(*) AS TotalVisits
FROM `VisitorLog`
WHERE 
    VisitorID NOT IN 
        (SELECT VisitorID FROM `VisitorLog` WHERE `URL` LIKE '%page=checkout%')
GROUP BY VisitorID

Answer 2

select VisitorID, count(*)
from VisitorLog
where (select count(*) from VisitorLog v2 where v2.VisitorID = VisitorLog.VisitorID and v2.URL like '%page=checkout%') = 0
;

Answer 3

我假设您的 visitorLog 表中的 URL 字段是foreign_key 和整数字段。

SELECT v1.VisitorID, COUNT(v1.VisitorID) AS TotalVisits
FROM `VisitorLog` v1, ?? as v2
WHERE v1.URL = v2.URL_ID
AND v2.URL NOT LIKE "%page=checkout%"
GROUP BY VisitorID

据我了解，例如。

id      visitor_id    datetime    page
1       1             Nov4        about us
2       1             Nov4        contact us
3       2             Nov4        about us
4       2             Nov3        about us
5       2             Nov4        home
6       1             Nov4        home


    select visitor_id, count(id) as numberofvisits 
    FROM visit_table_transaction 
    WHERE datetime = "Nov4"
    GROUP BY visitor_id
    HAVING numberofvisits > 2

So the result is 
visitor_id      numberofvisits
1               3

为什么需要使用having，因为聚合函数不能在WHERE中使用

http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html

你也可以 这样写的

select visitor_id, count(id) as numberofvisits 
FROM visit_table_transaction 
WHERE datetime = "Nov4"
GROUP BY visitor_id
HAVING count(id) > 2

下面是

 select visitor_id, count(id) as numberofvisits 
 FROM visit_table_transaction 
 WHERE datetime = "Nov4"
 AND count(id) > 2
 GROUP BY visitor_id 

，如有错误，请大家指正。
谢谢。