La réponse de @ Martin est correcte. C'est un génie.
Allez Martin !
CORRECTION
Sa réponse fonctionne avec 1 petite modification si elle est exécutée contre la solution bidirectionnelle que j'ai donnée. Sinon, les résultats sont incorrects.
Alors ta réponse est la sienne et la mienne :)
La solution complète :
DECLARE @T1 TABLE (calling_party VARCHAR(50), called_party VARCHAR(50))
INSERT INTO @T1
SELECT *
FROM dbo.monthly_connections_test
INSERT INTO @T1
SELECT *
FROM (
SELECT called_party AS calling_party, calling_party AS called_party
FROM dbo.monthly_connections_test AS T2
WHERE T2.called_party < T2.calling_party
) T2
WHERE NOT EXISTS (
SELECT *
FROM monthly_connections_test
WHERE calling_party = T2.calling_party and called_party = T2.called_party
)
select u1, u2, count(called_party) called_parties
from (
select distinct u1, u2, called_party from
(
select a1.calling_party u1, a2.calling_party u2 from
(select calling_party from @T1 group by calling_party) a1,
(select calling_party from @T1 group by calling_party) a2
) pairs,
@T1 AS T
where
(u1 <> u2) and
((u1 = t.calling_party and u2 <> t.called_party) or
(u2 = t.calling_party and u1 <> t.called_party))
) res
group by u1, u2
order by u1, u2
