Re: SQL - Querying the Same Table

["Joel Cochran" <joelcochran@xxxxxxxxx>]

OK, as I said that would only work if the combination was unique, so that
changes the problem set a little.  You might try this approach:

select select a.ASN
from myfile a
where a.companynumber = 1
and exists (select * from myfile b where b.ASN = a.ASN and b.companynumber =
2)

This should list all the ASNs that have both a company 1 and a company 2.