PHP inside echo HTML?

You can concatenate strings with the result of a php function:

echo '<div id="bg" style="background:url(' . get_stylesheet_directory_uri() . '/assets/img/header_2.jpg);">'; 

Codex: get_stylesheet_directory_uri()

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