Question

I have following tables:

**visitors**
+---------------------+--------------+------+-----+---------+----------------+
| Field               | Type         | Null | Key | Default | Extra          |
+---------------------+--------------+------+-----+---------+----------------+
| visitors_id         | int(11)      | NO   | PRI | NULL    | auto_increment |
| visitors_path       | varchar(255) | NO   |     |         |                |
+---------------------+--------------+------+-----+---------+----------------+

**fedora_info**
+----------------+--------------+------+-----+---------+-------+
| Field          | Type         | Null | Key | Default | Extra |
+----------------+--------------+------+-----+---------+-------+
| pid            | varchar(255) | NO   | PRI |         |       |
| owner_uid      | int(11)      | YES  |     | NULL    |       |
+----------------+--------------+------+-----+---------+-------+

First I looking for visitors_path that are related to specific pages by:

SELECT visitors_id, visitors_path
FROM visitors
WHERE visitors_path REGEXP '[[:<:]]fedora/repository/.*:[0-9]+$';

The above query return expected result.

now .*:[0-9]+ in above query referred to pid in second table. now I want know count of result in above query grouped by owner_uid in second table.

How can I JOIN this tables?

EDIT

sample data:

visitors
+-------------+---------------------------------+
| visitors_id | visitors_path                   |
+-------------+---------------------------------+
|        4574 | fedora/repository/islandora:123 |
|        4575 | fedora/repository/islandora:123 |
|        4580 | fedora/repository/islandora:321 |
|        4681 | fedora/repository/islandora:321 |
|        4682 | fedora/repository/islandora:321 |
|        4704 | fedora/repository/islandora:321 |
|        4706 | fedora/repository/islandora:456 |
|        4741 | fedora/repository/islandora:456 |
|        4743 | fedora/repository/islandora:789 |
|        4769 | fedora/repository/islandora:789 |
+-------------+---------------------------------+

fedora_info
+-----------------+-----------+
| pid             | owner_uid |
+-----------------+-----------+
| islandora:123   |         1 |
| islandora:321   |         2 |
| islandora:456   |         3 |
| islandora:789   |         4 |
+-----------------+-----------+

Expected result:
+-----------------+-----------+
| count           | owner_uid |
+-----------------+-----------+
| 2               |         1 |
| 4               |         2 |
| 3               |         3 |
| 2               |         4 |
| 0               |         5 |
+-----------------+-----------+

Answer 1

I suggest you to normalize your database. When inserting rows in visitors extract pid in the front end language and put it in a separate column (e.g. fi_pid). Then you can join it easily.

The following query might work for you. But it’ll be little cpu intensive.

SELECT 
       COUNT(a.visitors_id) as `count`,
       f.owner_uid
FROM   (SELECT visitors_id, 
               visitors_path, 
               SUBSTRING(visitors_path, ( LENGTH(visitors_path) - 
                                          LOCATE('/', REVERSE(visitors_path)) ) 
                                        + 2) AS 
                      pid 
        FROM   visitors 
        WHERE  visitors_path REGEXP '[[:<:]]fedora/repository/.*:[0-9]+$') AS `a`

JOIN fedora_info AS f 
         ON ( a.pid = f.pid ) 

GROUP  BY f.owner_uid