category__not_in — anyway to use category name instead of id?

You can use List Category Posts (Disclaimer: I’m the author of List Category Posts) or you can code this yourself:

$category_id = get_cat_ID($category_name);

This way you can get the id and exclude it from the loop with the minus sign. Example:

get_posts(cat=-1);

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