Why query works in ssms but not tableau?

I am not sure if anyone has ever worked with Tableau but thought that i would give this a shot. Anybody have any insights to offer?

Instead of dragging tables in the data source tab, I chose to use custom sql query. This same query returns the correct headings and data when I execute it in SQL server management studio. However, I enter it in tableau and click "Update Now". It does nothing. Below is the query that I am using. Now if I drag the labforce table and others, I can find the data in tableau so I know it exists. Any ideas why the SQL query returns nothing?

select laborforce,emplab,unemp,unemprate from dbo.labforce where area='000000' and adjusted = '0' and periodtype = '03' and periodyear in (select max(periodyear) from dbo.labforce) and period in (select max(period) from dbo.labforce)