I think it's to have the web page say "showing 20 results" and links for "page 2, page 3" etc.?
> On Sep 22, 2016, at 5:46 AM, Emmanuel Lécharny <[email protected]> wrote: > >> Le 22/09/16 à 10:42, Doan Tin Nghia a écrit : >> Thanks. I need it for paging (same issue like >> https://sourceforge.net/p/ldap-sdk/mailman/message/29370418/) > > Ok, but let me ask you aain : why do you technically need to know how > many entries you will get ? > > This information is totally spurious, unless you want to tell your > client "you are going to get 1 238 654 entries". > > Most of the time, and I saw that many, many times by people trying to > implemented an web page with back and forth buttons, the answer is "But, > but, but, I *NEED* to know how many elements I wil get in order to > correctly design my web page, otehrwise I will not be able to know if I > will have a next page !!!". This is typically wrong. If you decide to > show N elements in one page, and have a Next button, then just poll 2xN > elements from the backend, and if you get more than N elements, you know > that you will have a Next button. > > FTR, those using a RDBMS are frequently doing a selectcount(*) before > doing the real select for the exact same reason, and this is STUPID : > they are doing the exact same request *TWICE*, overloading teh server. > Be smart. >
