Table: Calls
| Column Name | Type |
|---|---|
| from_id | int |
| to_id | int |
| duration | int |
This table does not have a primary key, it may contain duplicates. This table contains the duration of a phone call between from_id and to_id. from_id != to_id
Write an SQL query to report the number of calls and the total call duration between each pair of distinct persons (person1, person2) where person1 < person2.
Return the result table in any order.
The query result format is in the following example.
Example 1:
Input: Calls table:
| from_id | to_id | duration |
|---|---|---|
| 1 | 2 | 59 |
| 2 | 1 | 11 |
| 1 | 3 | 20 |
| 3 | 4 | 100 |
| 3 | 4 | 200 |
| 3 | 4 | 200 |
| 4 | 3 | 499 |
Output:
| person1 | person2 | call_count | total_duration |
|---|---|---|---|
| 1 | 2 | 2 | 70 |
| 1 | 3 | 1 | 20 |
| 3 | 4 | 4 | 999 |
Explanation: Users 1 and 2 had 2 calls and the total duration is 70 (59 + 11). Users 1 and 3 had 1 call and the total duration is 20. Users 3 and 4 had 4 calls and the total duration is 999 (100 + 200 + 200 + 499).
SELECT person1,
person2,
count(*) call_count,
sum(duration) total_duration
FROM (SELECT IF(from_id > to_id, to_id, from_id) person1,
IF(from_id > to_id, from_id, to_id) person2,
duration
FROM Calls) c
GROUP BY person1,
person2