Hello 2011/12/8 Ingmar Brouns <swi...@gmail.com>: > > Hi, > > The documentation of the function concat states: Concatenate all arguments. > NULL arguments are ignored. > Intuitively I would expect that > > concat(NULL, NULL) IS NULL > > but this is not the case as it equals the empty string. As no empty string > was passed, the empty string seems > to come from nowhere. I found this behavior not immediately clear from the > documentation.. >
yes - it returns empty string - concat is "barier" to nulls it should be better documented Regards Pavel Stehule > Kind regards, > > Ingmar Brouns > > > -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
