How can I convert this SQL query into CodeIgniter's query builder?
SELECT
t.idkas,
t.tglkas,
(
SELECT (SUM(kredit))-(SUM(debet))
FROM kaskecil t2
WHERE t2.idkas <= t.idkas
) AS total
FROM kaskecil t
$this->db->select("t.idkas, t.tglkas, ((SELECT SUM(kredit) - SUM(debet) FROM kaskecil t2 WHERE t2.idkas <= t.idkas) AS total)", FALSE);
$this->db->from("kaskecil t");
$query = $this->db->get();