Use something like this : (add it in your function.php) and load your site once. after it finish, deactivate the function. (don’t forget to declare your $postID)
function my_update_posts() {
$count_key = 'post_views_count';
$args = array(
'post_type' => 'post',
'numberposts' => -1
);
$myposts = get_posts($args);
foreach ($myposts as $mypost){
$mypost->post_title = $mypost->post_title.'';
$count = rand(700,999);
update_post_meta($postID, $count_key, $count);
wp_update_post( $mypost );
}
}
add_action( 'wp_loaded', 'my_update_posts' );