Svein, Bhavbhuti has a background as a Visual FoxPro developer and in that language exist empty dates.
Probably is the reason why he had casted an empty string as a timestamp. The same thing had happened to me when I was learning SQL. Greetings. Walter. On Tue, May 13, 2014 at 4:02 AM, Svein Erling Tysvær svein.erling.tysv...@kreftregisteret.no [firebird-support] < firebird-support@yahoogroups.com> wrote: > > > >Thanks Svein. Would you suggest I double COALESCE it? I think it will > be an overkill and I might end up with an ANSI datetime again. > >Or should I not COALESCE it at all? I wanted a blank date time in case > of a NULL for tBillDt and if there is a date in tBillDt I need > >it for date calculation later on as post processing from the front ends. > > What is a blank date, Bhavbhuti? Either it is NULL (unknown) or an actual > date. Blank as in '' is a (var)char concept, it doesn't exist for dates or > timestamps and give an error. So you basically have to choose between > having a date for calculation or a string for display. > > If you're thinking in terms of WHERE clauses, you may sometimes use IS > [NOT] DISTINCT FROM as an alternative to = or <>. > > HTH, > Set > > >
