Getting only one post per category

$args = array(                          
'post_type' => 'Portfolio',
'tax_query' => array(
    array(
        'taxonomy' => 'portfolio_categories',
        'terms' => $slug,
        'field' => 'slug',
    )
),
'orderby' => 'ID',
'order' => 'DESC',
'posts_per_page' => -1
);

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