Oracle how to find total time for device by primary key, knowing start date and end date ?

Question

PHP

Oracle how to find total time for device by primary key, knowing start date and end date ?

Answer 1

You can add another column with duration.
Selecting by calculated columns is very slow. You can do it a couple of times, but regularly it's not right.

Answer 2

Why not write like this:

SELECT SUM( t.ts_inserted - t.ts_cleared ) secs
FROM table t
WHERE t.device_id = ?
AND ? BETWEEN t.ts_cleared AND t.ts_inserted