I need to update the value of a single column in an Oracle table with the value from a column in another table. The column has a "not null" constraint so I am getting an error saying the constraint has been violated. When I query both tables for null values in the respective columns, the counts are always zero. So I am guessing the following syntax is wrong:

update Staff_Archive set
   FirstName = (select FirstName from reglocator
                where reglocator.keynum = staff_archive.staff_id)

(Sorry for the post in VFP forum. I meant to post this here instead.)