Update MAP field with lat,lng,zoom

<?php

function add_custom_query_var( $vars ){
    $vars[] = "save_all_posts";
    return $vars;
}
add_filter( 'query_vars', 'add_custom_query_var' );

function trigger_save_all_posts() {
    if (intval(get_query_var('save_all_posts')) === 1) {
        $args = array(
            'post_type'      => 'restoran', // your post type
            'post_status'    => 'publish',
            'posts_per_page' => -1,
        );

        $all_posts = get_posts($args);

        foreach ($all_posts as $post) {
            $latitude = get_post_meta($post->ID, 'latitude', true); // latitude field
            $longitude = get_post_meta($post->ID, 'longitude', true); // longitude field
            $zoom = "14"; // zoom
            $location_string = $latitude . ',' . $longitude . ',' . $zoom;
            update_post_meta($post->ID, 'map',$location_string); // map field
            echo '* ';
        }

        exit;
    }
}
add_action( 'template_redirect', 'trigger_save_all_posts' );