How to select multiple categories in this db query?

I’m not so good with the mysql database commands, so whenever I need something special I can only copy what exists out there.
Anyways, I’m adapting some code and I need my query to choose several category id’s, but the code I found only chooses one. How do I change it so it will select more category id’s?
The piece of the query:
AND wp_term_taxonomy.term_id = {$category_id}

Thanks