FYI, in oracle you can use Analytical Functions to do this in one query. In other db's you can do this: select username, x.* from customlist, (select count(*) from customlist) as x;
-----Original Message----- From: Igor Vaynberg [mailto:[EMAIL PROTECTED] Sent: Friday, March 21, 2008 11:44 AM To: users@wicket.apache.org Subject: Re: DataView size() iterator() call order issue knowing the size and the window together seems like a ui requirement, it is a bit strange to me that you have it inside a dao which should cater to business logic. eg, as far as i know there is no single db operation that will produce both, so you are still doing two calls inside the dao. also transaction management should be handled outside the dao, daos are too fine an object to implement transaction management for. anywho, just nitpicking :) size() is called first for a lot of reasons, namely even knowing if there are any rows to retrieve before a much heavier iterator() is called. some clients want to hide a repeater if there are no items visible, and so size() might get called from inside isvisible() as well. idataprovider is quiet old and we havent had many complaints about its design so far. if all you are using is the dataview it should be pretty simple for you to roll your own dataview, if you look at dataview all it does is implement idataprovider handling to feed the pageable view. however, if you do you will also lose datatable as well :| if you got suggestions on how to improve it im all ears. -igor On Fri, Mar 21, 2008 at 11:24 AM, Hoover, William <[EMAIL PROTECTED]> wrote: > When using DataView/IDataProvider size() is called before iterator(int first, int count) causing calls to DAOs to be duplicated. Our current framework that is internally using Hibernate allows one call to be made to a DAO that returns both the total result size and the actual records (based off first/count). The problem is that the first and count are unknown until the iterator method is called- forcing multiple calls to the DAO to retrieve the data (also forcing multiple transactions). What are the reasons behind calling size before iterator? > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
