Using rows from the first query in the sub-query? - mysql

Question

I have a bit complicated query:
SELECT SQL_CALC_FOUND_ROWS DISTINCT l1.item_id, l1.uid, l2.id, l2.uid, u.prename, l1.item_id, l2.item_id,
(SELECT SUM(cnt) FROM
(
SELECT DISTINCT
p1.item_id,
COUNT(*) AS cnt
FROM pages_likes AS p1
JOIN pages_likes AS p2 ON p1.item_id = p2.item_id AND p1.status = p2.status
WHERE p1.uid = 391 AND p2.uid = 1091
GROUP BY p1.id
ORDER BY p1.date DESC
) AS t) AS total
FROM pages_likes l1
JOIN users u on u.id = l1.uid
JOIN pages_likes l2 on l1.item_id = l2.item_id
JOIN users_likes ul on l1.uid = ul.uid
WHERE ul.date >= DATE_SUB(NOW(),INTERVAL 1 WEEK)
AND l1.uid != 1091 AND l2.uid = 1091
AND (l1.status = 1 AND l2.status = 1)
AND u.gender = 2
GROUP BY l1.uid
ORDER BY
total DESC,
l1.uid DESC,
l1.date DESC
What I expect: It should display all users, sorted by total page likes we have in common that also are the most liked users this week.
The thing is that I inserted values (391 and 1091) as user id to test the query. But since it should be dynamic I'll need to use the row of the first query l1.uid in the subquery, so it should be WHERE p1.uid = l1.uid AND p2.uid = 1091 but mysql can't find the row.
status = 1 means user liked this page, status = 0 means user disliked this page.
Table structure here:
CREATE TABLE pages_likes
(
id BIGINT PRIMARY KEY NOT NULL AUTO_INCREMENT,
uid INT NOT NULL,
date DATETIME NOT NULL,
item_id INT,
status TINYINT
);
CREATE INDEX item_index ON pages_likes (item_id);
CREATE INDEX uid_index ON pages_likes (uid);
CREATE TABLE users
(
id BIGINT PRIMARY KEY NOT NULL AUTO_INCREMENT,
fb_uid VARCHAR(255),
email VARCHAR(100) NOT NULL,
pass VARCHAR(50) NOT NULL,
gender TINYINT NOT NULL,
birthdate DATE,
signup DATETIME NOT NULL,
lang VARCHAR(10) NOT NULL,
username VARCHAR(255),
prename VARCHAR(255) NOT NULL,
surname VARCHAR(255) NOT NULL,
projects VARCHAR(255) NOT NULL,
views INT DEFAULT 0,
verified DATETIME
);
CREATE UNIQUE INDEX id_index ON users (id);
CREATE INDEX uid_index ON users (id);
CREATE TABLE users_likes
(
id INT PRIMARY KEY NOT NULL AUTO_INCREMENT,
uid INT NOT NULL,
date DATETIME NOT NULL,
item_id INT,
status TINYINT
);
CREATE INDEX item_index ON users_likes (item_id);
CREATE INDEX uid_index ON users_likes (uid);

Answer 1

Have you tried different alias names for your subquery and then use alias from outer query? It works for me in this simple example: http://rextester.com/MJOL87502
Sadly I cannot test in your sqlfiddle, since that site often doesn't respond or throws errors (like it does now).
You could also use Window Functions and replace your subselect with something as simple as SUM(*) OVER (PARTITION BY p1.id, p1.item_id), but MySQL does not support Window Functions.