SELECT
    
    *,
    task_description AS task_description_clean,
    task_title AS task_title_clean,
    ROUND(tk.fee*IFNULL(SUM(TIME_TO_SEC(TIMEDIFF(IF(tt.end_time='0000-00-00 00:00:00',now(),tt.end_time), tt.start_time)))/3600,0),2) AS total_fee,
    
    ROUND(SUM(TIME_TO_SEC(TIMEDIFF(IF(tt.end_time='0000-00-00 00:00:00',now(),tt.end_time), tt.start_time)))/3600,2) AS total_time
    

FROM

    tasks AS tk
    LEFT JOIN
    time_tracker AS tt
        ON tt.element_id = tk.task_id AND tt.element_type=2,
    invoice_task AS it,
    projects AS pt
     
WHERE

    invoice_id = '##invoice_id##'
    AND tk.task_id = it.task_id
    AND tk.project_id = pt.project_id
    
GROUP BY tk.task_id

ORDER BY

    it.add_date DESC