Very simple LIMIT query trouble is blocking me - php

Question

I have the following PHP code:
$page = $_POST["page"];
$pageSize = $_POST["pageSize"];
$toRecord = $page * $pageSize;
$fromRecord = $toRecord - $pageSize;
$query = "SELECT * FROM table LIMIT $fromRecord, $toRecord";
Now, out of 10 total table records, if my $pageSize is '3', the first page returns me 3 records, the 2nd 6 records, the 3rd 4 records, and the last one 1 record. I have limited experience in SQL, what am I doing wrong?

Answer 1

LIMIT params are offset, row_count. So you should use not $toRecord, but $pageSize there - and don't forget about escaping it. In fact, I'd rewrite this logic a bit:
define('DEFAULT_PAGE_NO', 1);
define('DEFAULT_PAGE_SIZE', 10);
if (isset($_POST['page']) {
$pageNo = max(DEFAULT_PAGE_NO, (int)$_POST['page']);
}
else {
$pageNo = DEFAULT_PAGE_NO;
}
if (isset($_POST['pageSize']) {
$pageSize = (int)$_POST['pageSize'];
if ($pageSize <= 0) {
$pageSize = DEFAULT_PAGE_SIZE;
}
}
else {
$pageSize = DEFAULT_PAGE_SIZE;
}
$offset = ($pageNo - 1) * $pageSize;
$query = "SELECT * FROM table LIMIT $offset, $pageSize";