need help using table multiple times within select

I hope someone out here can help me. I am writing a bill of materials report. We have 1 file that has the parent and component. What I need to do is to keep reading the file matching the component to an alias parent to see if it has components. Where I am having problems is when I reach a level where the component is not a parent. The query will not return a match. I know that there has to be a way to do a join so that it will return a null if the component is not there. Anyone have any ideas? Libi Maniace BEI Sensors & Systems (501) 851-5417 lmaniace@beissd.com