How to make a query that, when fetching, excludes a certain date?

Question

SQL

Good afternoon!
Help with drawing up a query, you need to make a selection in which you want to exclude a certain date.
I do this, but something tells me that this is not how it is done.
Select* from users where not birthday in ('yyy-mm-dd')

Answer 1

birthday != ''
birthday NOT IN(...,...,...)
birthday NOT LIKE '...'
the first option is the most optimal, the rest for other cases

Answer 2

Normally, this is how it is done. In general, in is for a set of values, but no one will cover you with shame and contempt if you have only one value there. But not like - this is not necessary.