CREATE TABLE gifts(sender varchar, recipient varchar, text varchar)

select count(*), a.recipient as rec, a.sender as sen from (select sender, recipient from gifts) as a,(select sender, recipient from gifts) as b where a.sender = b.recipient or a.recipient = b.sender group by rec,sen order by 1

group by min(sender,recipient), mах(sender,recipient)

group by LEAST(sender,recipient), GREATEST(sender,recipient)

CREATE TABLE gifts(sender varchar, recipient varchar)
INSERT INTO gifts (sender, recipient)
VALUES
(1, 2)
,(1, 3)
, (1, 4)
, (2, 3)
, (3, 1)
, (3, 4)
, (3, 2)

SELECT
	[One]
	, [Two]
	, COUNT(*) AS N
FROM (
SELECT
	sender AS [One]
	, recipient AS [Two]
FROM gifts
UNION ALL
SELECT
	recipient AS [One]
	, sender AS [Two]
FROM gifts
) t
WHERE [One] > [Two]
GROUP BY [One], [Two]
ORDER BY N DESC

DROP TABLE gifts