Ниво 10.3 на задачата SQL
Дадени са таблици:
| id | name |
|---|---|
| 1 | John |
| 2 | Andrew |
| 3 | Kevin |
| 4 | Mark |
| 5 | Eric |
| id | user_id | start | end |
|---|---|---|---|
| 1 | 2 | 2023-01-10 18:39:02 | 2023-02-10 16:57:33 |
| 2 | 1 | 2023-01-10 18:39:06 | 2023-02-10 16:57:07 |
| 3 | 5 | 2023-03-08 10:22:04 | 2023-03-09 12:11:57 |
| 4 | 5 | 2023-01-10 23:59:03 | 2023-01-11 13:15:33 |
| 5 | 2 | 2023-08-31 18:22:05 | 2023-08-31 11:55:25 |
| 6 | 3 | 2023-11-02 22:12:10 | 2023-11-03 08:32:20 |
| 7 | 4 | 2023-10-13 20:33:10 | 2023-10-13 11:55:15 |
| 8 | 3 | 2023-09-30 08:01:01 | 2023-09-30 10:02:05 |
| 9 | 2 | 2023-02-13 23:39:05 | 2023-02-14 05:41:31 |
| 10 | 1 | 2023-08-09 10:22:11 | 2023-08-09 10:44:43 |
| 11 | 1 | 2023-10-12 17:59:49 | 2023-10-12 20:49:48 |
| 12 | 5 | 2023-11-11 05:31:43 | 2023-11-11 05:59:55 |
| 13 | 2 | 2023-11-20 08:00:59 | 2023-11-21 18:32:58 |
| 14 | 1 | 2023-11-26 08:57:32 | 2023-11-26 19:30:55 |
| 15 | 4 | 2023-04-12 11:33:39 | 2023-04-12 23:51:29 |
| 16 | 3 | 2023-04-30 17:30:27 | 2023-04-30 20:40:26 |
| 17 | 2 | 2023-01-10 19:22:52 | 2023-01-12 13:11:24 |
| 18 | 3 | 2023-10-15 11:22:13 | 2023-10-16 14:33:32 |
| 19 | 4 | 2023-05-31 15:44:55 | 2023-06-03 11:32:11 |
| 20 | 5 | 2023-07-10 07:57:12 | 2023-07-10 20:48:33 |
Решете следните задачи за тях:
Намерете потребителя, който е прекарал най-много време в системата през последния месец, като се вземат предвид всички негови сесии.
