> -----Original Message----- > From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general- > owner@xxxxxxxxxxxxxx] On Behalf Of Scott Marlowe > Sent: Wednesday, January 19, 2005 5:54 PM > To: Rick Schumeyer > Cc: pgsql-general@xxxxxxxxxxxxxx > Subject: Re: sorting library of congress numbers > > On Wed, 2005-01-19 at 16:37, Rick Schumeyer wrote: > > I have a table where one of the columns is a library of congress > > number. > > > > I would like to be able to ORDER BY this column. > > > > > > > > Currently, the column is a varchar. Unfortunately, a normal string > > comparison > > > > will not work. > > > > > > > > First, has anyone done this already? > > > > > > > > If not, I'm thinking I would need to: > > > > 1) define a new type to hold LOC numbers. > > > > 2) write a function that determines less than, greater than > > > > > > > > It seems like I'm missing something here. I have not yet defined a > > new > > > > type.is defining less/greater part of that process? > > > > > > > > Is there a simpler way to do this? > > You might want to do something along the lines of storing the PARTs of > the loc number, then using lpad/rpad in a function to put them together > in such a way to as to render them orderable. Is there an URL on how > LOC numbers are ordered? LOC numbers are described at: http://library.dts.edu/Pages/RM/Helps/lc_call.shtml I thought about breaking the pieces up. I will have to think a bit more about whether that will work. ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
