Find top 5 famous people - sql

Question

I have a case in hand where I need to find the top 5 people with most likes on their posts overall.
Here's the schema:
CREATE TABLE users (
ID SERIAL PRIMARY KEY,
created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
username VARCHAR(30) NOT NULL,
);
CREATE TABLE posts (
id SERIAL PRIMARY KEY,
created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
url VARCHAR(300) NOT NULL,
user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
);
CREATE TABLE likes (
id SERIAL PRIMARY KEY,
created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
contents VARCHAR(240) NOT NULL,
user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
post_id INTEGER REFERENCES posts(id) ON DELETE CASCADE,
comment_id INTEGER REFERENCES comments(id) ON DELETE CASCADE,
-- 👉 either associated with post or comment 👈 --
CHECK(
COALESCE((post_id)::boolean::integer, 0) +
COALESCE((comment_id)::boolean::integer, 0) = 1
),
-- user can like post/comment once --
UNIQUE (user_id, post_id, comment_id)
);
My Attempts
Both are giving different outputs, not sure which one is correct. Also, I would appreciate an ideal (scalable) solution for this:
1.
WITH FAMOUS AS (
SELECT likes.id, users.username AS username, users.id AS user_id
FROM likes
JOIN posts ON posts.user_id = likes.post_id
JOIN users ON users.id = likes.user_id
WHERE likes.comment_id IS null
)
SELECT COUNT(*) AS num, username FROM FAMOUS
GROUP BY username
ORDER BY num DESC LIMIT 5;
2.
WITH LIKES_DATA AS (
SELECT post_id, COUNT(*) AS num_likes_per_post FROM likes
WHERE likes.comment_id IS NULL
GROUP BY post_id
)
SELECT users.username, SUM(num_likes_per_post) as num_likes
FROM LIKES_DATA
JOIN posts ON posts.id = LIKES_DATA.post_id
JOIN users ON users.id = posts.user_id
GROUP BY users.username
ORDER BY num_likes DESC LIMIT 5;

Answer 1

I simply do not understand the thought process for the second query.
Based on your description, I think just using JOINs and GROUP BY is sufficient:
SELECT u.username AS username, u.id AS user_id, COUNT(*)
FROM likes l JOIN
posts p
ON p.user_id = l.post_id JOIN
users u
ON u.id = l.user_id
WHERE likes.comment_id IS NULL -- don't know what this is for
GROUP BY u.username, u.id
ORDER BY COUNT(*) DESC
LIMIT 5;