Problem Description –
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.
Problem Link – Calls between two persons
Difficulty Level – Medium
SELECT LEAST(from_id, to_id) as person1, GREATEST(from_id, to_id) as person2, COUNT(*) as call_count, SUM(duration) as total_duration FROM Calls GROUP BY 1, 2