Med dina identifierare:
SELECT a.userId , a.LanguageId, b.LanguageId
FROM knownlanguages a inner join knownlanguages b
on a.userID=b.userID and a.LanguageId < b.LanguageId
Testning:Fottabell:
create table t ( u int, l int);
insert into t values
( 1, 2),
( 1, 7),
( 1, 8),
( 2, 10),
( 2, 3);
Frågan är:
select t1.u, t1.l as l1, t2.l as l2
from t t1 inner join t t2
on t1.u = t2.u and t1.l < t2.l
( Resultat )