MySQL Error No: 1064 when INSERTING to Database - php

Question

Below is my table which is similar to another existing table. But I get one error when executing the query.
//
public function addFirstChild() {
$this->db->query("INSERT INTO " . $this->db->table("genealogy") . "
WHERE parent_id = '" . (int)$this->getSponsorID() . "'
SET first_child = '" . (int)$this->getId()."',
genealogy_id = '" . (int)$this->getId() ."'");
}
When executed I get the below Error:
SQL Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE parent_id = '1' SET first_child = '2', ' at line 2
Error No: 1064
SQL: INSERT INTO ci_genealogy WHERE parent_id = '1' SET first_child = '2', genealogy_id = '2' in C:\wamp64\www\s1nb2\core\database\amysqli.php on line 108
There's no other way that I can think of to pull of this function and I have searched online and read multiple posts with the same error but still no solution. Please help. I spent over 4 hours trying to get this right.

Answer 1

Since you're using a WHERE it appears that you want to change an existing record. You want an UPDATE, not an INSERT
"UPDATE " . $this->db->table("genealogy") . "
SET first_child = '" . (int)$this->getId()."', genealogy_id = '" . (int)$this->getId() ."'
WHERE parent_id = '" . (int)$this->getSponsorID() . "'"