Sometimes, we require to run directly mysql query on Laravel for example if you need to copy one table to other table using mysql query. I also need in one project and that's why i am fetching problem. But you can use sql query on laravel using db statement in bellow example you can learn how to run.
<pre class="prettyprint lang-php">
INSERT INTO `posts` (repost_of_id,token_id,post_details,user)
FROM `posts` where id = ".$postId."