MySQL + PHP pagination with no offset - mysql

Question

Ok, here is the code i have for my pagination:
$SQL = "SELECT
cpc.product_id,
cp.product_internal_ref,
cp.product_name,
cpa.product_sale_price,
cpa.is_product_service,
cpa.product_service_price,
cpi.image_name,
cpi.image_ext
FROM catalog_products_categories cpc
JOIN catalog_products cp ON cp.product_id = cpc.product_id
JOIN catalog_products_attributes cpa ON cpa.product_id = cpc.product_id
LEFT JOIN catalog_products_images cpi ON cpi.product_id = cpc.product_id
WHERE cpc.category_id = ".$catID;
// PAGINATOR SECTION
if($paginatorVARS['paginatorACTION'] == "next") {
$SQL .= " AND cpc.product_id > ".$paginatorVARS['paginatorGOID']." ";
$SQL .= "GROUP BY cpc.product_id ORDER BY cpc.product_id ASC LIMIT ".$paginatorVARS['catalogPaginatorPAGEROWS'];
}
elseif($paginatorVARS['paginatorACTION'] == "prev") {
$SQL .= " AND cpc.product_id < ".$paginatorVARS['paginatorGOID']." ";
$SQL .= "GROUP BY cpc.product_id ORDER BY cpc.product_id DESC LIMIT ".$paginatorVARS['catalogPaginatorPAGEROWS'];
}
// END PAGINATOR SECTION
I used the method described here: http://www.slideshare.net/Eweaver/efficient-pagination-using-mysql but i can't seam to find a way to also sort by other columns like for example by cpa.product_sale_price. If i do : ORDER BY cpc.product_id ASC, cpa.product_sale_price DESC/ASC it will break the paginator next results i dont know what happens... Please help!!

Answer 1

not saying their stuff is perfect, but it is often a place to start, to consider if you really want to reinvent the wheel, or take their concepts and incorporate it into your new rounder wheel. take a look at
http://dev.sencha.com/deploy/ext-4.0.0/examples/grid/paging.html
and use fiddler to examine the http gets that are occuring during pagination, as well as changes in the sort context. when it starts out it brings back the http response header, json data with jsonp callback, and top node value at the end of the json data specifying record count=6679 / 50 per page meaning 134 pages total as calculated by the front-end. the record count can vary from call to call (from page to page) as rows are inserted and deleted.
the sort column gets passed in the query string just like the pages impact the limit start,total that goes into sql. this can be seen in fiddler output showing changes in pages or sort column requests (column name, and asc or desc):
GET /forum/topics-browse-remote.php?_dc=1369401925806&page=1&start=0&limit=50&sort=lastpost&dir=DESC&callback=Ext.data.JsonP.callback1 HTTP/1.1
GET /forum/topics-browse-remote.php?_dc=1369401977137&page=1&start=0&limit=50&sort=replycount&dir=ASC&callback=Ext.data.JsonP.callback2 HTTP/1.1
GET /forum/topics-browse-remote.php?_dc=1369401978355&page=1&start=0&limit=50&sort=replycount&dir=DESC&callback=Ext.data.JsonP.callback3 HTTP/1.1