Kevin, Thanks. That was a direct copy/paste. It happened that the *UNION*ed queries spat out those results in the same order that the queries appeared.
Just want to again emphasize that my database state has changed, so I am not sure this is remains a good case for finding a bug. Aren On Sun, Mar 18, 2012 at 3:33 PM, Kevin Grittner <kevin.gritt...@wicourts.gov > wrote: > "Kevin Grittner" <kevin.gritt...@wicourts.gov> wrote: > > Aren Cambre <a...@arencambre.com> wrote: > > > >> SELECT COUNT(*) > >> FROM consistent.master > >> WHERE citation_id IS NOT NULL > >> UNION > >> SELECT COUNT(*) > >> FROM consistent.master > >> UNION > >> SELECT COUNT(*) > >> FROM consistent.master > >> WHERE citation_id IS NULL > >> > >> I got this result: > >> > >> 2085344 > >> 2085343 > >> 0 > >> > >> Not clear how adding a WHERE clause, whose only practical effect > >> is to reduce the number of rows returned, could cause *more* rows > >> to be returned. > > > Never assume that the rows will be returned in any particular > > order from a query unless you specify ORDER BY. > > Hmm. That doesn't explain why the numbers don't add up, though. Is > that a copy/paste from an actual query run, or was there some > hand-editing there? In particular, you might easily get that result > if that last line was really: > > WHERE citation_id = '' > > instead of the IS NULL test. In the ANSI standard and in PostgreSQL > there is a big difference between an empty string and NULL, although > there is at least one product I know of which breaks from standard > compliance by treating them as equivalent. > > -Kevin >
