Обсуждение: Howto only select secific lines from a result?
Hi, I am working on a graphical table display widget which should be able to display huge amounts of data, by lazy-loading database values. It already works well if the primary-key and line-number are equal. However I don't have any idea howto handle the case where the primary-key contains holes, caused e.g. by deleting a few entries. What I would need is a LIMIT command, which allows to LIMIT the results in two ways. Is there some way to select only specific lines from a result, something like: Select * from table Where RESULNR BETWEEN 1000 and 1040? Or do you have any other ideas howto solve this problem? Thank you in advance, Clemens
On 8 August 2010 02:37, Clemens Eisserer <linuxhippy@gmail.com> wrote: > Hi, > > I am working on a graphical table display widget which should be able > to display huge amounts of data, by lazy-loading database values. It > already works well if the primary-key and line-number are equal. > However I don't have any idea howto handle the case where the > primary-key contains holes, caused e.g. by deleting a few entries. > > What I would need is a LIMIT command, which allows to LIMIT the > results in two ways. > Is there some way to select only specific lines from a result, something like: > Select * from table Where RESULNR BETWEEN 1000 and 1040? > > Or do you have any other ideas howto solve this problem? > > Thank you in advance, Clemens > > -- http://www.postgresql.org/docs/8.4/static/queries-limit.html -- Thom Brown Registered Linux user: #516935
On 8 Aug 2010, at 3:37, Clemens Eisserer wrote: > What I would need is a LIMIT command, which allows to LIMIT the > results in two ways. > Is there some way to select only specific lines from a result, something like: > Select * from table Where RESULNR BETWEEN 1000 and 1040? > > Or do you have any other ideas howto solve this problem? I think cursors are what you're looking for. Start reading from: http://www.postgresql.org/docs/8.4/interactive/sql-declare.html Alban Hertroys -- If you can't see the forest for the trees, cut the trees and you'll see there is no forest. !DSPAM:737,4c5e73eb286211213419466!