Navigate Throught MySQL Result - php

Question

I have searched everywhere but could not get anything. The scenario is that when I run a select statement from MySQL/PHP, I want to use Next & Previous buttons to navigate backwards and forward through the results.
Does anyone know how I can accomplish this?
Here's how I run the query: select everything from members where hair = black;
This returns 8 results, and I have a page like so details.php?id=3 which takes id and display the details.
I want to be able to keep clicking the next button and move to another id from the result.
How do I accomplish this?
Thank you for your assistance.

Answer 1

If you mean to display 1 product details per page with Next buttons, then
1) Get the total rows from table
2) Find total number of pages like
$totalPages = $totalRows; //since 1 record per page
3) Loop thru $totalPages value to generate next links
4) Get the id of product from page url $_GET
5) Query sql using te product id obtained frm GET
Well thats the basics, hope your get it

Answer 2

Assuming you have all ids in the $allIds var, try something like this:
<?php
$id = (int) $_GET['id'];
$key = array_search($id, $allIds);
$nextId = $allIds[$key+1];
?>

Answer 3

Well, you have 2 different scopes here to address, first, when you query you are in PHP/Server side mode. PHP gets some data, processes it, shows some of it to the knowledge i have of your problem and then sends it to the browser.
Next, you have the client scope, where the client has the HTML rendered to his screen and has the possibility to click NEXT and PREVIOUS. When he does that, he issues a request to the server to get the NEXT or PREVIOUS record based on the current one.
You have 2 scenarios to work this problem out:
1) Load the whole data into memory and scan it to find your current position, see if there is a NEXT and PREVIOUS element and respond to the request of the user. If the user asked for the NEXT, easy, just move one more record. If the user asked for PREVIOUS item, then when scanning using a WHILE or FOR/FOREACH, always keep in memory the "lastitem" you saw, you can use this "lastitem" as your PREVIOUS item.
2) In the event you have many (i mean like more than 1000) items, you need to use a little subquery magic and work this out using SQL.
select everything from members where hair = black AND id = XYZ ORDER BY id LIMIT 2;
This will return you the CURRENT AND NEXT elements. Then call the same query again but this time, order it DESC so that your 2 items are the CURRENT AND PREVIOUS.
select everything from members where hair = black AND id = XYZ ORDER BY id DESC LIMIT 2;
Note that you can order this the way you want, the goal is to get a static result, something that always gets out the same way so that you can reverse it and get the items around the selected one.
I hope this helps you