Thread

1. Unable to convert null timestamp to date. Bug?

   Edmar Wiggers <edmar@brasmap.com> — 2000-12-07T23:08:09Z

   Strange, this works:
     select * from users where last_visit > now() + 7; 
     -- last_visit is nullable, of type timestamp
   
   But this doesn't
     select * from users where last_visit + 7 > now();
     ERROR:  Unable to convert null timestamp to date
     -- yes, there are users where last_visit IS NULL
   
   BTW, this works too:
     select null+1; -- obviously returns NULL
   
   System is FreeBSD 4.1, PgSQL 7.0.2
   
   Anyone got a clue?
   
   Yours sincerely,
   
   Edmar Wiggers
   BRASMAP Information Systems
   +55 48 9960 2752
   
   

2. Re: [SQL] Unable to convert null timestamp to date. Bug?

   Tom Lane <tgl@sss.pgh.pa.us> — 2000-12-08T01:01:51Z

   "Edmar Wiggers" <edmar@brasmap.com> writes:
   >   select * from users where last_visit + 7 > now();
   >   ERROR:  Unable to convert null timestamp to date
   
   Yeah, someone who hadn't quite grokked the concept of NULL seems to have
   written a lot of the date.c code :-(.
   
   This is fixed for 7.1.  If it's really bothering you in 7.0.*, see
   src/backend/utils/adt/date.c, and change code like
   
       if (!PointerIsValid(timestamp))
           elog(ERROR, "Unable to convert null timestamp to date");
   
   to
   
       if (!PointerIsValid(timestamp))
   	return NULL;
   
   in several places.
   
   			regards, tom lane