The following query works fine:

Select ProdName as AliasName1
from Product p, Machines m
where p.MachineID = m.MachineID
and AliasName1 = 'TEST'

But the following self join does not work:

Select p1.ProdName as AliasName1
from Product p1, Product p2
where p1.MachineID = p2.MachineID
and AliasName1 = 'TEST'

Pervasive produce an error:
"Invalid Column Name p1"

WHY????
Any suggestion to overcome the problem please...