How can I count the number of posts?

Question

Here is my table structure:

-- reputations
+----+-------------+---------+-------+------------+------------+
| id | post_id     | user_id | score | reputation | d         


        

Answer 1

I post this using mobile phone so I cannot try it on the fiddle you gave. I modify your SQL to count number of post using COUNT.

SELECT
t.tag, 
sum(r.reputation) AS tag_reputation, 
sum(r.score) AS tag_score,
COUNT(DISTINCT pt.post_id) AS post_num
FROM
users u
LEFT JOIN reputations r 
    ON r.user_id = u.id 
        AND r.date_time > 1500584821
JOIN post_tag pt ON pt.post_id = r.post_id
JOIN tags t ON t.id = pt.tag_id
WHERE u.id = 1 -- Specific user: Jack
GROUP BY
u.id, u.user_name, t.tag 
ORDER BY
u.id, tag_reputation DESC;

Edit: I add COUNT with DISTINCT. See if it solve.