Create mysql sum column when multiple other columns are true

Question

I want to create a column in mysql workbench where there is a sum of the duration of a behaviour when multiple columns (eg condition, trial, subject, behaviour type...) are the same.

I am relatively new to working in sql and have so far mostly just used it for extracting data. Is this something that is possible? If so how do I go about it?

Thanks :)

Edit - The data would be something like this

Condition  Trial   Group  Subject  Behaviour  Duration   **TotalDuration**  
np         1       XX     GBF132   interact   00:00:42  
np         1       XX     GBF132   interact   00:00:17   
yp         1       ZZ     HJR543   interact   00:01:03            
yp         1       ZZ     HJR543   interact   00:00:26  

So there could be multiple interactions within a trial by the same individual and I would like to determine the overall interaction duration per trial.

But I have multiple subjects/behaviours/Groups per trial and condition so need a way to easily calculate the total duration of each behaviour when the condition, trial, group, subject, behaviour are the same .

I hope this makes it clearer!

Answer 1

AFAIK in recent MySQL versions they've added support for window functions. It seems that those functions can be used to solve your problem. I didn't test it, but it would be used somewhat like that:

SELECT
  `condition`, `trial`, `group`, `subject`, `behaviour`,
  `duration`,
  SEC_TO_TIME(SUM(TIME_TO_SEC(`duration`))) OVER (PARTITION BY condition`, `trial`, `group`, `subject`, `behaviour`) AS timeSum
FROM `tests`;

Anyway, for older versions of MySQL the following might work for you:

SELECT
   `condition`,
   `trial`,
   `group`,
   `subject`,
   `behaviour`,
   `duration`, SEC_TO_TIME(SUM(TIME_TO_SEC(`duration`)))
FROM `tests`
GROUP BY `condition`, `trial`,`group`, `subject`,`behaviour`;

but that way you would kind of lose the "details". To replicate the way window functions work you would need to use something like:

SELECT `t1`.`condition`, `t1`.`trial`,`t1`.`group`, `t1`.`subject`,`t1`.`behaviour`, `t2`.`duration`,`t1`.`totalTime` FROM (SELECT
  `condition`,
  `trial`,
  `group`,
  `subject`,
  `behaviour`,
  `duration`, SEC_TO_TIME(SUM(TIME_TO_SEC(`duration`))) AS totalTime
FROM `tests` AS subt1
GROUP BY `condition`, `trial`,`group`, `subject`,`behaviour`) AS t1
JOIN `tests` AS t2 USING (`condition`, `trial`,`group`, `subject`,`behaviour`);

Here's the code snippet I've played around: http://sqlfiddle.com/#!9/e002f2/12/0