How to check different strings for the same value?

Question

MySQL

There is a table for linking posts and tags

And I need to pull out, for example, a post_id that has both tag_id 2 and 8.
I can find records with tag_id 2, save its post_id and search for this post_id also tag_id 8, but there can be 5 and it will be +100500 requests.
Or maybe you have other ideas for implementing linking tags to posts and searching through them?

Answer 1

SELECT post_id
FROM Tags
WHERE tag_id IN (1,2 ,5 , 10, 100)
www.dofactory.com/sql/where-in

Answer 2

SELECT DISTINCT post_id FROM table_name WHERE tag_id IN (2, 8, 100500);

Answer 3

HAVING sum(1) = &total_tag_coung