How can I check two conditions before inserting?

Question

I have three tables:

// Posts
+----+----------+---------------+-----------+
| id |  title   |    content    | id_author |
+----+----------+---------------+--         


        

Answer 1

INSERT INTO Votes (id_post,id_user)
SELECT p.id, u.id
FROM Posts p
    INNER JOIN Users u ON 1 = 1
WHERE p.id_user = :author
    AND u.id = :current_user_id
    AND u.active = 1
LIMIT 1;