Passing a Result set between pages - Good Idea ?

zebedee

Still getting to grips with PHP, and having a bit of a problem.

Scenario:
I have a search page.. when submitted returns the results page. pretty straightforward, but...
In my results page, i make a call to DB according to the user inputs, however i only want to display say 10 items per page.

If my links to the other items are basically links to the same page, but displaying the next 10 items and so on, l figure I have to pass the entire result set as a variable from the 1st page to the 2nd and so on, however:
a) is this a bad idea because potentially lots of data in the result set needs to be passed ? will this slow things up ?
b) how do i get specific rows of the result set so that i can dislpay the correct rows according to what page the user is currently on. ie rows 1-10 for 1st page 11-20 for 2nd page and so on, or does a pointer stay on the results set at the last row i accessed (despite having being passed between pages )?

Or is there a much better way to do it ?

Any suggestions would be magic 🙂

nnichols

You definitely do not want to put the complete result set into an array and then pass the array from page to page. Not a cunning plan.

The way I normally do it is with something like this -

<?
$rows_per_page = 10;
if (isset($_GET['page']))
	$page = $_GET['page'];
else
	$page= 1;

$offset = ($page-1)*$rows_per_page;

$sql = "SELECT * FROM user LIMIT $offset, $rows_per_page";

?>

Hope this helps 😉

zebedee

Yeh i thought it was probably a bad idea !!! Thanx 🙂

One other thing

I am trying to code with functions (used to java) but getting major confused with how variables are used in PHP

For example in the code below the variable $page, how do i make that variable accessable to a number of functions within the page, ie i will want to use it in my function displayResults() and also in displayPageMenu()

nnichols

function displayResults() {
global $page;
// do your stuff


}

Hope this helps 😉

mwdrago

hello, another newbie here. I'm doing something similar with my search function and your suggestion above helped a lot, thanks. I was just wondering how do you put the link to the second, third, fourth pages, etc?

Do you just put the page variable in the link?

<a href="url.php?page=2"></a>

nnichols

You need to get the total number of rows that are going to be returned and divide it by the number of rows per page and then print a url as you suggested.

I am just in the process of writing a proper newbies tutorial on this topic.

If you search around there are some good tutorials on this and there are some really good posts on here as well.

Hope this helps 😉