On May 24, 2012, at 9:04 AM, Jacques Le Roux wrote: > From: "Jacopo Cappellato" <jacopo.cappell...@hotwaxmedia.com> >> On May 23, 2012, at 9:25 PM, Adam Heath wrote: >> >>> On 05/23/2012 01:13 PM, Jacopo Cappellato wrote: >>>> Using count() was simply a trick to be sure to get a record back even if >>>> the entity is empty... but if we use an entity that we are sure is >>>> populated we don't have to use it, of course. Of course if we use count(*) >>>> we have to use it in an entity with a very low number of rows... but I too >>>> would prefer to avoid it. >>> >>> select 1; >> >> Thank you Adam, this is the "trick" I was looking for when I mentioned >> option #3 in my first email. >> I will test the system with it and then commit. >> >> Jacopo > > Which entity will you use Jacopo?
When I first saw Adam's comment I thought he was suggesting to simply execute "select 1" in order to run a "query" with no table to return a "record" with one field containing 1. But I maybe misunderstood the suggestion and at least on Derby this doesn't seem to work; but I still need to fully test. In my opinion adding a new entity for this would be an overkill; one solution could be the following: select count(key_name) from entity_key_store where 1 = 2 that always returns one record and should be efficient on mostly all dbs. Jacopo > > Jacques
