Question

I have a table like this

CREATE TABLE `air_video` (
`id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`date` DATE NOT NULL,
`time` TIME NOT NULL,
`asset_id` INT(10) UNSIGNED NOT NULL,
`duration` TIME NOT NULL,
`name` VARCHAR(100) NOT NULL,
PRIMARY KEY (`id`),
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB;

There are entries with the same asset_id, duration and name, but different date and time. These are same videos that were aired multiple times during some time.

I need to calculate total duration for distinct videos grouped by each month.
Please give some ideas?

Answer 1

So you need the sum of the duration of each distinct video per month:

select
  year,
  month,
  sec_to_time(sum(time_to_sec(duration))) as totaltime
from
  (select distinct
    av.asset_id,
    av.duration,
    year(av.date) as year,  
    month(av.date) as month
  from
    air_video av)
group by
  year,
  month

So you’ll need the sum of durations, grouped per video per month…

Smart use of grouping as suggested by RobertHarvey in the comments (thanks).
time_to_sec is used to convert a time value to seconds so it can be summed.

select
  av.asset_id,
  year(av.date) as year,  
  month(av.date) as month,
  sec_to_time(sum(time_to_sec(av.duration))) as totaltime
from
  air_video av
group by
  av.asset_id,
  year(av.date), 
  month(av.date)