Adding `post_author` in php

Try this

<div class="my_edit_button">
<?php if ( $post->post_author == $current_user->ID ) {
echo do_shortcode('[something]'); 
}?>
</div>

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)