<[EMAIL PROTECTED]> wrote on 03/02/2006 06:55:14 AM: > This might be a bit odd, but here we go.. > > I have some data in a table that has the following structure: > > CREATE TABLE `gaugereportinglist` ( > > `Updated` timestamp NOT NULL default > CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP, > `StartTimeAndDate` datetime NOT NULL, > > `Time_Offset` double default NULL, > > `OutgoingPcntGgeDev` float default NULL, > > `IncomingPcntGgeDev` float default NULL, > > `MillSpeed` float default NULL, > > `PassNumber` int(2) default NULL, > > KEY `STADIndex` (`StartTimeAndDate`) > > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 > > The data is logged once a second. The StartTimeAndDate will be the same > for the particular workpiece that I am interested in. > I pull out the data with a select statement such as "select > `OutgoingPcntGgeDev` from gaugereportinglist where > `StartTimeAndDate`="2006-03-02 09:36:09" This can give me, say, 3 to 4 > thousand rows. I am using BIRT (www.eclipse.org/birt) to do my > reporting. These value are shown on a graph. However 3000 points on a > small graph on a web page is a little over the top, and takes a long > time to plot. Is there any way to select say, every 10th point without > doing anything on the client side?
You can do it if you store your current results into a temporary table with an auto_increment column in it. Then you can run a query on your temporary table looking for rows where MOD(auto_inc_column_name,10) =0 The MOD() operator returns the remainder that comes from dividing the first parameter by the second. http://dev.mysql.com/doc/refman/4.1/en/mathematical-functions.html If you wanted to get every 20th term, just change the 10 to a 20. See the pattern? Shawn Green Database Administrator Unimin Corporation - Spruce Pine
