Using one sub query result multiple times in the same mysql query - mysql

Question

How can we use result set of one subquery multiple times in the same query
SELECT
(
SELECT
COUNT(joa.id)
FROM
game_applied joa
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) be ON joa.referred_by = be.id
) AS applicationcount,
(
SELECT
COUNT(joa.id)
FROM
game_applied joa
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) bf ON joa.referred_by = bf.id
AND joa.admin_review = '3'
AND joa.rejection_reason = 'Admin rejected your game'
) AS admin_reject,
(
SELECT
COUNT(joa.id)
FROM
game_applied joa
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) bg ON joa.referred_by = bg.id
AND joa. STATUS = '5'
AND joa.admin_review = '2'
) AS employer_reject,
(
SELECT
COUNT(joa.id)
FROM
game_applied joa
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) bd ON joa.referred_by = bd.id
AND joa.admin_review = '1'
) AS admin_review,
(
SELECT
COUNT(joa.id)
FROM
game_applied joa
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) bc ON joa.referred_by = bc.id
AND joa.admin_review = '5'
) AS accountmanager_review,
(
SELECT
COUNT(joa.id)
FROM
game_applied joa
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) ba ON joa.referred_by = ba.id
AND joa.admin_review = '6'
) AS rp_review,
(
SELECT
COUNT(joa.id)
FROM
game_applied joa
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = 1
) bh ON joa.referred_by = bh.id
AND joa.admin_review = '2'
AND (
joa. STATUS = '' || joa. STATUS = 1 || joa. STATUS = 2 || joa. STATUS = 3 || joa. STATUS = 4
)
) AS other_status
FROM
game_applied ja
JOIN user_user u ON u.id = ja.applied_recruiter_id
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) bn ON ja.referred_by = bn.id
GROUP BY
applicationcount
How can we use result set of one subquery multiple times in the same query
the sub query used mulitple times in this query to a single use
(
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) bn ON ja.referred_by = bn.id

Answer 1

Try this:
SELECT COUNT(joa.id) AS applicationcount,
SUM(joa.admin_review = '3' AND joa.rejection_reason = 'Admin Rejected your resume') AS admin_reject,
SUM(joa.STATUS = '5' AND joa.admin_review = '2') AS employer_reject,
SUM(joa.admin_review = '1') AS admin_review,
SUM(joa.admin_review = '5') AS accountmanager_review,
SUM(joa.admin_review = '6') AS rp_review,
SUM(joa.admin_review = '2' AND joa.STATUS != '5') AS other_status,
FROM game_refer_to_member jrmm
INNER JOIN game_refer jrr ON jrr.id = jrmm.rid AND jrr.referby_user_id = 2551
INNER JOIN game_applied joa ON jrmm.id = joa.referred_by
INNER JOIN user_user u ON u.id = joa.applied_recruiter_id
WHERE jrmm.STATUS = '1'

Answer 2

OK... I'll try to figure out what the query does first. I'll replace all instances of:
SELECT
COUNT(joa.id)
FROM
game_applied joa
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
with the phrase:
( SELECT count(*) FROM joa JOIN (subselect))
...for clarity.
I also removed the GROUP BY, since it is useless and/or misguided, unless you can explain why it is there.
I assume ja.applied_recruiter_id is a foreign key, which means...
JOIN user_user u ON u.id = ja.applied_recruiter_id
...always returns one row. Since no columns from user_user are actually selected, this join can be removed. Now, this part:
INNER JOIN (
SELECT
jrmm.id
FROM
game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1'
) bn ON ja.referred_by = bn.id
...it is unclear what this does. Since the subselect is the same as the one in the previous queries, it is unlikely that it would filter lines returned by the whole query. I'd say its only effect is to uselessly duplicate lines, which explains why there was a GROUP BY... So, off it goes.
We get:
SELECT
( SELECT count(*) FROM joa JOIN (subselect)) be ON joa.referred_by = be.id ) AS applicationcount,
( SELECT count(*) FROM joa JOIN (subselect)) bf ON joa.referred_by = bf.id
AND joa.admin_review = '3'
AND joa.rejection_reason = 'Admin rejected your game'
) AS admin_reject,
( SELECT count(*) FROM joa JOIN (subselect)) bg ON joa.referred_by = bg.id
AND joa. STATUS = '5'
AND joa.admin_review = '2'
) AS employer_reject,
( SELECT count(*) FROM joa JOIN (subselect)) bd ON joa.referred_by = bd.id
AND joa.admin_review = '1'
) AS admin_review,
( SELECT count(*) FROM joa JOIN (subselect)) bc ON joa.referred_by = bc.id
AND joa.admin_review = '5'
) AS accountmanager_review,
( SELECT count(*) FROM joa JOIN (subselect)) ba ON joa.referred_by = ba.id
AND joa.admin_review = '6'
) AS rp_review,
( SELECT count(*) FROM joa JOIN (subselect)) bh ON joa.referred_by = bh.id
AND joa.admin_review = '2'
AND (joa. STATUS = '' || joa. STATUS = 1 || joa. STATUS = 2 || joa. STATUS = 3 || joa. STATUS = 4)
) AS other_status
FROM
game_applied ja
...And, using the same logic as Sarhash, we simplify this into:
SELECT COUNT(joa.id) AS applicationcount,
SUM(joa.admin_review = '3' AND joa.rejection_reason = 'Admin Rejected your resume') AS admin_reject,
SUM(joa.STATUS = '5' AND joa.admin_review = '2') AS employer_reject,
SUM(joa.admin_review = '1') AS admin_review,
SUM(joa.admin_review = '5') AS accountmanager_review,
SUM(joa.admin_review = '6') AS rp_review,
SUM(joa.admin_review = '2' AND joa.STATUS != '5') AS other_status,
FROM game_refer_to_member jrmm
INNER JOIN game_refer jrr ON jrr.id = jrmm.rid
INNER JOIN game_applied joa ON jrmm.id = joa.referred_by
WHERE jrmm.STATUS = '1' AND jrr.referby_user_id = 2551
(which is the same, minus the useless join to USER and a cleanup in the WHERE, thank you Sarhash, you get all the credit).

Answer 3

I found a working solution using CREATE TEMPORARY TABLE. I'd suggest running two queries back to back in the same session. First, create some temporary tables from the subqueries you want to reference multiple times:
CREATE
TEMPORARY TABLE temp_table1
(SELECT COUNT(joa.id)
FROM game_applied);
CREATE
TEMPORARY TABLE new_table
(SELECT jrmm.id
FROM game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = '1');
After running a simple find-and-replace on your original query using these temporary table names, the new query would look like this:
SELECT
(SELECT *
FROM temp_table1 joa
INNER JOIN temp_table2 be ON joa.referred_by = be.id) AS applicationcount,
(SELECT *
FROM temp_table1 joa
INNER JOIN temp_table2 bf ON joa.referred_by = bf.id
AND joa.admin_review = '3'
AND joa.rejection_reason = 'Admin rejected your game') AS admin_reject,
(SELECT *
FROM temp_table1 joa
INNER JOIN temp_table2 bg ON joa.referred_by = bg.id
AND joa. STATUS = '5'
AND joa.admin_review = '2') AS employer_reject,
(SELECT *
FROM temp_table1 joa
INNER JOIN temp_table2 bd ON joa.referred_by = bd.id
AND joa.admin_review = '1') AS admin_review,
(SELECT *
FROM temp_table1 joa
INNER JOIN temp_table2 bc ON joa.referred_by = bc.id
AND joa.admin_review = '5') AS accountmanager_review,
(SELECT *
FROM temp_table1 joa
INNER JOIN temp_table2 ba ON joa.referred_by = ba.id
AND joa.admin_review = '6') AS rp_review,
(SELECT *
FROM temp_table1 joa
INNER JOIN
(SELECT jrmm.id
FROM game_refer_to_member jrmm
JOIN game_refer jrr ON jrr.id = jrmm.rid
AND jrr.referby_user_id = 2551
AND jrmm. STATUS = 1) bh ON joa.referred_by = bh.id
AND joa.admin_review = '2'
AND (joa. STATUS = '' || joa. STATUS = 1 || joa. STATUS = 2 || joa. STATUS = 3 || joa. STATUS = 4)) AS other_status
FROM game_applied ja
JOIN user_user u ON u.id = ja.applied_recruiter_id
INNER JOIN temp_table2 bn ON ja.referred_by = bn.id
GROUP BY applicationcount
I'm not guaranteeing that this query is without bugs, since I don't have your database and therefore cannot easily test it, but this at least outlines a decent strategy that I think should improve performance, and at very least makes the query about half the size.