Well, basically it can be done to an extent in some kind of code. Basically I am drawing from a table 2 records at a time. I want to make sure that all records are pulled at least once. If at all possible not to have 2 from the same vendor.
So, in this case. I have columns id, html, vendor So I can add columns as needed. I tried adding a flag and after returning to the client the 2 records I'd mark it as flag = 1 then search like this Select id, html from urls order by flag, id desc limit 3 Then after I have those I would then set the last of the 3 to flag = 1 so that on the next search I get the 2 after. In theory it worked fine but when multiple people hit the page simultaneously I had flags in different places and not in order. Maybe just mark them as flag = 1 after returned and then on search if found is 0 then set all to flag = 0 so they can be seen again? This doesn't seem so bad but them I guess I'd use distinct? If I cant use distinct with other parameters... ex: select id,html distinct(vendor) from urls where flag=0 limit 2; Would it be like : Select id,html from urls where flag = 0 group by distinct(vendor) limit 2 ? Thanks Steffan --------------------------------------------------------------- T E L 6 0 2 . 5 7 9 . 4 2 3 0 | F A X 6 0 2 . 9 7 1 . 1 6 9 4 Steffan A. Cline [EMAIL PROTECTED] Phoenix, Az http://www.ExecuChoice.net USA AIM : SteffanC ICQ : 57234309 The Executive's Choice in Lasso driven Internet Applications Lasso Partner Alliance Member --------------------------------------------------------------- > From: Rhino <[EMAIL PROTECTED]> > Date: Fri, 12 May 2006 14:20:10 -0400 > To: "Steffan A. Cline" <[EMAIL PROTECTED]>, <mysql@lists.mysql.com> > Subject: Re: Returning records in a circle > > > ----- Original Message ----- > From: "Steffan A. Cline" <[EMAIL PROTECTED]> > To: <mysql@lists.mysql.com> > Sent: Friday, May 12, 2006 1:38 PM > Subject: Returning records in a circle > > >> Is there a way I can get a set of records incrementally such as to get 2 >> then the next query get the next 2 then at the end of all records to get >> the >> 2 from the beginning? I need to keep going incrementally by 2 in a circle. >> > > Are you trying to get these rows purely via SQL at the command line or in an > SQL script? Or would an application be an option for you? > > If you are not willing to consider application code to grab the rows you > want, the answer to your question is "maybe". SQL has always been intended > to return ALL of the rows that satisfy a query with a single invocation of > the query, no matter how many rows that is. So if your query says: > > select * from mytab; > > you will normally get all of the rows that satisfy that query in one go, > whether there are 0 rows, 100 rows, or a 100 million rows in the result. > > You _might_ be able to get the results you want by using the LIMIT clause. > I'm not sure what version of MySQL you are using but the LIMIT clause is > described in the MySQL 3.23/4.0/4.1 manual on this page: > http://dev.mysql.com/doc/refman/4.1/en/select.html. The problem is that > you'll still pretty much need some sort of script in order to keep executing > the query to get the next two records and you may need to change the > parameters of the LIMIT clause at the same time. > > If you are willing to write application code, things get a lot easier. For > instance, a Java program could easily grab rows from a result set for you > two at a time, let you process them, then grab two more, etc. I expect that > it would similarly easy to do the same thing in Perl and PHP and C. > > In short, a program gives you a lot more ability to do what you want to do > with your database data. But some shops have very little programming > expertise and prefer to do everything via SQL. If you work for one of those > shops, you might not be able to get your records two at a time with SQL > alone, unless you can write a script that takes advantage of the LIMIT > clause. > > I don't pretend to know MySQL exhaustively so someone else may have another > suggestion for you but the only two approaches I can think of that might > meet your needs are to use the LIMIT clause or to write an application. > > -- > Rhino > > > > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.1.392 / Virus Database: 268.5.6/337 - Release Date: 11/05/2006 > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
