# 1699. Number of Calls Between Two Persons

https://leetcode.com/problems/number-of-calls-between-two-persons

## Description

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:

```
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      |
+---------+-------+----------+
Result table:
+---------+---------+------------+----------------+
| person1 | person2 | call\_count | total\_duration |
+---------+---------+------------+----------------+
| 1       | 2       | 2          | 70             |
| 1       | 3       | 1          | 20             |
| 3       | 4       | 4          | 999            |
+---------+---------+------------+----------------+
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).
```

## ac

```java
```
