resolving an offset value

[eladchen]

Hey, im using MSSQL server ( i know ) im trying to build pagination class for my photos page

this is the query im using to retrive data

$sql_query  = "WITH Photos AS (SELECT ROW_NUMBER() OVER(ORDER BY id) "; 
$sql_query .= "AS RowNumber, id, filename, type, size, caption FROM photographs) "; 
$sql_query .= "SELECT * FROM Photos WHERE RowNumber BETWEEN {$pagination->offset_start()} AND {$pagination->offset_start()}";

 

the query works fine im using 3 veriables to keep track of

$current_page for the current page number,

$per_page for the results per page i want to display,

$total_count for the total items;

 

im using two functions - $pagination->offset_start() and $pagination->offset_end()

if the result per page veriable is 3 then offset_start() should return 0 and offset_end() should return 3

then when im on page number 2 they should return 4 to 7 hence 3 results per page..

and if for example $per_page is 36 then it should return 0 to 36 on the first page

on the seconed page it should return 37 to 73.

i cant figure out the math and will love some help please.

i hope to god it's nothing simple or else i'l feel like a complete idiot..

 

P.S sorry for any bad english  

[eladchen]

SOLVED - using this

 

	public function offset_start()
{
	// in case $per_page is 5 - first value will be 1
	// seconed value will be 6, third will be 11 and so on..
	$offset_start = ($this->current_page - 1) * $this->per_page;
	return $offset_start + 1;
}

public function offset_end()
{
	$offset_end = ($this->current_page - 1) * $this->per_page;
	return $offset_end + $this->per_page;
}