How do I get data from multiple tables if the agency_code doesn't match
You can achieve that by using this select:

select ef.employee_number,ef.full_name,ef.agency_code
from Employment_Form  ef, HumanResources hr
where ef.employee_number = hr.employee_number
and ef.agency_code &lt;&gt; hr.agency_code;


Here you select all the columns of the Employment_Form table, fetching only those rows with matching employee_number and wrong agency_code.

If that full_name is the same on both tables, you can either use it, instead of employee_number , like this

select ef.employee_number,ef.full_name,ef.agency_code
from Employment_Form  ef, HumanResources hr
where ef.full_name = hr.full_name
and ef.agency_code &lt;&gt; hr.agency_code;


The output would be the same.

Hope this helps.