How to form SQL query correctly?

Question

MySQL

Hello. Simple problem.
There is a table user_com in the database with the following fields
id, id_user, comment
1 #123 comment...
2 #123 comment...
3 #654 comment...
4 #334 comment...
5 #123 comment...
6 # 334 comment...
7 #123 comment...
I need to display id_user in a loop without repeating users
It should turn
out 1 id_user #123
2 id_user #654
3 id_user #334
So that they do not repeat

Answer 1

select id_user from user_com group by id_user

Answer 2

SELECT * FROM `user_com` GROUP BY `id_user`