I’ve been meaning to request this for a very long time.  Just haven’t gotten around to it until now.  Sybase’s SQL Anywhere has a feature called KEY JOIN that allows you to join two tables using the foreign key relationship without having to specify the fields in the “ON” clause. 
See < http://dcx.sybase.com/1101/en/dbusage_en11/key-joins-aspen.html>. 
It’s a great feature, but in AquaData the Auto Complete doesn’t work correctly if you use the KEY JOIN.  Not sure what it would take to make this work, but sure would be nice.