where table_a.id != table_b.id

[Stooney]

I am trying to fetch results from a table where IDs in table_b are not in table_a, if that makes sense.  I can't quite figure out how to do this properly, here's what I'm envisioning:

 

SELECT table_b.id FROM table_a, table_b WHERE table_b.id != table_a.id

 

Example

table_a:

id -> 1, 2, 4, 5, 7, 9

 

table_b:

id -> 1, 2, 3, 4, 5, 6, 7, 8, 9

 

I would want to retrieve 3, 6, 8 because those IDs are not in table a. 

[Cagecrawler]

SELECT table_b.id FROM table_b WHERE table_b.id NOT IN (SELECT table_a.id FROM table_a)