Count number of rows under different conditions in one query?

Question

MySQL

Hello everyone, please tell me there is a table with comments, you need to combine 2 such simple queries into one:

SELECT COUNT(id) as one_count FROM comments WHERE user_id = $user_id AND post_id != 1

SELECT COUNT(id) as two_count FROM comments WHERE user_id = $user_id AND post_id = 1

those. You need to know how many comments in total from a specific user, minus the comments on a specific post, and you also need to know how many comments specifically for this post.
And in general, if it makes sense to combine all this into one query for optimization purposes?
Many thanks in advance to all for the help.

Answer 1

SELECT COUNT(id) as `count`, "one" as `name` FROM comments WHERE user_id = $user_id AND post_id != 1
UNION
SELECT COUNT(id) as `count`, "two" as `name` FROM comments WHERE user_id = $user_id AND post_id = 1
count | name
=============
12 | one
234 | two

Answer 2

SELECT 
SUM( IF(post_id != 1, 1, 0) ) as one_count,  
SUM( IF(post_id = 1, 1, 0) ) as two_count
FROM comments 
WHERE user_id = $user_id