"Rank Over" problem with SQL

I've got a friend trying to help me write an SQL expression that's over my head. I'm following along the best I can and trying not to be a complete burden. We are starting simple and adding on one step at a time. So far we have the source tables in and that produces a result (i.e. we can see the data). All the tables are left joined appropriately.

Here's where it goes sideways: my friend states that we need to use the following:
RANK() OVER ( partition by users.mbr_id order by skill_info.start_date desc ) as 'SEQ'
at the end of the SELECT string
When we try and run this, it doesn't work. Any ideas?

Hi @paintbb84
I would recommend asking in a forum dedicated to the database you're querying or stackoverflow.com