WP_QUERY post_in problem

As documented, it’s post__in, with two underscores:

$paramss = array( 'post__in' => array( 760, 761 ) , 'post_type' => 'product' );

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