How can I rewrite this SQL into CodeIgniter's Active Records? - sql

Question

SELECT *, SUM(tbl.relevance) AS relevance FROM
(
(
SELECT q_id,
MATCH(a_content) AGAINST ('бутон') AS relevance
FROM answers
WHERE
MATCH(a_content) AGAINST ('бутон')
)
UNION
(
SELECT q_id,
(MATCH(q_content) AGAINST ('бутон')) * 1.5 AS relevance
FROM questions
WHERE
MATCH(q_content) AGAINST ('бутон')
)
) AS tbl
JOIN questions ON questions.q_id = tbl.q_id
GROUP BY tbl.q_id
ORDER BY relevance DESC

Answer 1

Codeigniter currently does not have support for subqueries in its Active Records class.
You'll simply have to use this:
$this->db->query($your_query, FALSE);
Remember to pass that second argument, so that Codeigniter doesn't try to escape your query.

Answer 2

Well there is indeed a simple hack for subqueries in codeigniter. You have to do the following
Go to system/database/DB_active_rec.php
There if you are using version 2.0 or greater change this
public function _compile_select($select_override = FALSE)
public function _reset_select()
Remove public keyword and you will be able to use subqueries
And now
$data = array(
"q_id",
"MATCH(a_content) AGAINST ('?????') AS relevance"
);
$this->db->select($data);
$this->db->from("answers");
$this->db->where("MATCH(a_content) AGAINST ('?????')");
$subQuery1 = $this->db->_compile_select();
// Reset active record
$this->db->_reset_select();
unset($data);
$data = array(
"q_id",
"(MATCH(q_content) AGAINST ('?????')) * 1.5 AS relevance"
);
$this->db->select($data);
$this->db->from("questions");
$this->db->where("MATCH(q_content) AGAINST ('?????')");
$subQuery2 = $this->db->_compile_select();
// Reset active record
$this->db->_reset_select();
unset($data);
$data = array(
"q_id",
"SUM(tbl.relevance) AS relevance"
);
$this->db->select($data);
$this->db->from("$subQuery1 UNION $subQuery2");
$this->db->join("questions","questions.q_id = tbl.q_id");
$this->db->group_by("tbl.q_id");
$this->db->order_by("relevance","desc");
$query = $this->db->get();