Thumbnails for media Library images

wp_get_attachment_image($post->ID, 'size-1');

The “post thumbnail” actually gets the featured image that is attached to the post. For an attachment, you want the attachment itself in a specific size, which isn’t the same as the featured image.

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