MySQL SELECT combining 3 SELECTs INTO 1 - mysql

Question

Consider following tables in MySQL database:
entries:
creator_id INT
entry TEXT
is_expired BOOL
other:
creator_id INT
entry TEXT
userdata:
creator_id INT
name VARCHAR
etc...
In entries and other, there can be multiple entries by 1 creator. userdata table is read only for me (placed in other database).
I'd like to achieve a following SELECT result:
+------------+---------+---------+-------+
| creator_id | entries | expired | other |
+------------+---------+---------+-------+
| 10951 | 59 | 55 | 39 |
| 70887 | 41 | 34 | 108 |
| 88309 | 38 | 20 | 102 |
| 94732 | 0 | 0 | 86 |
... where entries is equal to SELECT COUNT(entry) FROM entries GROUP BY creator_id,
expired is equal to SELECT COUNT(entry) FROM entries WHERE is_expired = 0 GROUP BY creator_id and
other is equal to SELECT COUNT(entry) FROM other GROUP BY creator_id.
I need this structure because after doing this SELECT, I need to look for user data in the "userdata" table, which I planned to do with INNER JOIN and select desired columns.
I solved this problem with selecting "NULL" into column which does not apply for given SELECT:
SELECT
creator_id,
COUNT(any_entry) as entries,
COUNT(expired_entry) as expired,
COUNT(other_entry) as other
FROM (
SELECT
creator_id,
entry AS any_entry,
NULL AS expired_entry,
NULL AS other_enry
FROM entries
UNION
SELECT
creator_id,
NULL AS any_entry,
entry AS expired_entry,
NULL AS other_enry
FROM entries
WHERE is_expired = 1
UNION
SELECT
creator_id,
NULL AS any_entry,
NULL AS expired_entry,
entry AS other_enry
FROM other
) AS tTemp
GROUP BY creator_id
ORDER BY
entries DESC,
expired DESC,
other DESC
;
I've left out the INNER JOIN and selecting other columns from userdata table on purpose (my question being about combining 3 SELECTs into 1).
Is my idea valid? = Am I trying to use the right "construction" for this?
Are these kind of SELECTs possible without creating an "empty" column? (some kind of JOIN)
Should I do it "outside the DB": make 3 SELECTs, make some order in it (let's say python lists/dicts) and then do the additional SELECTs for userdata?
Solution for a similar question does not return rows where entries and expired are 0.
Thank you for your time.

Answer 1

This should work (assuming all creator_ids appear in the userdata table.
SELECT userdata.creator_id, COALESCE(entries_count_,0) AS entries_count, COALESCE(expired_count_,0) AS expired_count, COALESCE(other_count_,0) AS other_count
FROM userdata
LEFT OUTER JOIN
(SELECT creator_id, COUNT(entry) AS entries_count_
FROM entries
GROUP BY creator_id) AS entries_q
ON userdata.creator_id=entries_q.creator_id
LEFT OUTER JOIN
(SELECT creator_id, COUNT(entry) AS expired_count_
FROM entries
WHERE is_expired=0
GROUP BY creator_id) AS expired_q
ON userdata.creator_id=expired_q.creator_id
LEFT OUTER JOIN
(SELECT creator_id, COUNT(entry) AS other_count_
FROM other
GROUP BY creator_id) AS other_q
ON userdata.creator_id=other_q.creator_id;

Answer 2

Basicly, what you are doing looks correct to me.
I would rewrite it as follows though
SELECT entries.creator_id
, any_entry
, expired_entry
, other_entry
FROM (
SELECT creator_id, COUNT(entry) AS any_entry,
FROM entries
GROUP BY creator_id
) entries
LEFT OUTER JOIN (
SELECT creator_id, COUNT(entry) AS expired_entry,
FROM entries
WHERE is_expired = 1
GROUP BY creator_id
) expired ON expired.creator_id = entries.creator_id
LEFT OUTER JOIN (
SELECT creator_id, COUNT(entry) AS other_entry
FROM other
GROUP BY creator_id
) other ON other.creator_id = entries.creator_id

Answer 3

How about
SELECT creator_id,
(SELECT COUNT(*)
FROM entries e
WHERE e.creator_id = main.creator_id AND
e.is_expired = 0) AS entries,
(SELECT COUNT(*)
FROM entries e
WHERE e.creator_id = main.creator_id AND
e.is_expired = 1) as expired,
(SELECT COUNT(*)
FROM other
WHERE other.creator_id = main.creator_id) AS other,
FROM entries main
GROUP BY main.creator_id;