Perform full outer join in mysql - mysql

Question

I already know i can do outer join in MySQL using union.
I also check this one.
Full Outer Join in MySQL
But i want to do something like this and I don't know how can I achieve this using union.
I have db table user_count as follow.
+-------------+-----------+---------+-------+
| meb_id | left_id |right_id |active |
+-------------+-----------+---------+-------+
| 1001 | (NULL) | (NULL) | 1 |
| 1002 | 1001 | 0 | 0 |
| 1003 | 0 | 1001 | 0 |
| 1004 | 1001 | 0 | 0 |
| 1004 | 1002 | 0 | 0 |
+-------------+-----------+---------+-------+
I have queries as follow.
SELECT left_id, COUNT(left_id) AS left_count FROM `user_count` GROUP BY left_id
SELECT right_id, COUNT(right_id) AS right_count FROM `user_count` GROUP BY right_id;
SELECT left_id AS meb_id, COUNT(left_id) AS active_left_count FROM `user_count` WHERE active = 1 GROUP BY left_id;
SELECT right_id AS meb_id, COUNT(right_id) AS active_right_count FROM `user_count` WHERE active = 1 GROUP BY right_id;
I want to preform outer join or union so my result will be like this
+-------------+-----------+------------+------------+--------------+
| meb_id |left_count |right_count |active_left |active_right |
+-------------+-----------+------------+------------+--------------+
| (NULL) | 0 | 0 | 0 | 0 |
| 0 | 1 | 3 | 0 | 0 |
| 1001 | 2 | 1 | 0 | 0 |
| 1002 | 1 | 0 | 0 | 0 |
| 1003 | 0 | 0 | 0 | 0 |
+-------------+-----------+------------+------------+--------------+
How can i do this. Any help greatly appreciated.

Answer 1

Try this:
select
a.meb_id
,sum(case when a.meb_id = b.left_id then 1 else 0 end) left_count
,sum(case when a.meb_id = b.right_id then 1 else 0 end) right_count
,sum(case when a.meb_id = b.left_id and active = 1 then 1 else 0 end) active_left
,sum(case when a.meb_id = b.right_id and active = 1 then 1 else 0 end) active_right
from (
select meb_id from user_count union
select left_id from user_count union
select right_id from user_count
) a
cross join user_count b
group by a.meb_id
order by a.meb_id
Demo
sqlfiddle