> -----Original Message----- > From: Terry Fielder [mailto:terry@xxxxxxxxxxxxxxxxxxxx] > Sent: Wednesday, October 19, 2005 2:05 PM > To: Dann Corbit > Cc: Tino Wildenhain; Marc G. Fournier; Richard_D_Levine@xxxxxxxxxxxx; > pgsql-hackers@xxxxxxxxxxxxxx; pgsql-general@xxxxxxxxxxxxxx > Subject: Re: 'a' == 'a ' (Was: RE: [pgsql-advocacy] Oracle > buysInnobase) > > > > Dann Corbit wrote: > > Try this query in Oracle, SQL*Server, DB/2, Informix, etc.: > > > > connxdatasync=# select 1 where cast('a' as varchar(30)) = cast('a ' as > > varchar(30)); > > ?column? > > ---------- > > (0 rows) > > > > I see how you can interpret the SQL Standard to make the above response > > a correct one. But is it the response that you would like? > > When the compared datatypes are VARCHAR: YES What is the value of doing that? I can see plenty of harm and absolutely no return. We are talking about blank padding before comparison. Do you really want 'Danniel ' considered distinct from 'Danniel ' in a comparison? In real life, what does that buy you? And even if people think it is a good idea, it seems to be at odds with the way that I read the standard (though I am easily confused by simple enough language at times). It could well be that I am jaded from years of doing it the wrong way (I expect two character strings with all leading non-blanks in agreement to compare equal). Perhaps this is old hat to the long-timers around here and there is a good explanation as to why varchar should have non-blank padding when comparisons are performed. Can someone point me to documentation that explains it? [snip] ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your message can get through to the mailing list cleanly
