Слава Витренко

INSERT INTO main (`id`, `nazv`, `text`, `user_id`)
    VALUES (9, '{$nazv}', '{$text}', '{$user_id}')
    ON DUPLICATE KEY UPDATE 
        `text`=VALUES(`text`),
        `nazv`=VALUES(`nazv`),
        `user_id`=VALUES(`user_id`);

<?php
    private function LatLngDist($p, $q) {
        $R = 6371; // Earth radius in km

        $dLat = (($q[0] - $p[0]) * pi() / 180);
        $dLon = (($q[1] - $p[1]) * pi() / 180);
        $a = sin($dLat / 2) * sin($dLat / 2) +
                cos($p[0] * pi() / 180) * cos($q[0] * pi() / 180) *
                sin($dLon / 2) * sin($dLon / 2);
        $c = 2 * atan2(sqrt($a), sqrt(1 - $a));

        return $R * $c;
    }