Re: SQL - Querying the Same Table

So really, you aren't interested in the plant number (since the requirement
is that both plants must have a record).  In this case, you are only
interested in the ASNs that appear more than once.  It seem be simplistic,
but Grouping and Count(*) work great for this kind of stuff:

Select ASN, Count(*) as Count
from yourtable
group by ASN
having Count(*) > 1


This is, of course, assuming that the Plant number/ASN combination are
unique.