Different header for each category

Use the is_category() condtional statement

if(is_category('category-a-slug')){
    get_header('a');
}elseif(is_category('category-b-slug')){
    get_header('b');
}

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