SELECT phone_book WHERE last_name =%% AND last_name IS NOT NULL;

Here's my solution:

> SELECT last_name FROM phone_book WHERE last_name IS NOT NULL

It needs you to just get the last_name column when it isn't null

that worked. Awesome.

It looks like you were close Cosmin - also i believe that if you wanted to use the characters for string match %

Be sure to use the keyword LIKE for example LIKE %book%