SQLite 3.27

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

WITH People AS (

SELECT 91 AS age, 77 AS iq, 0 AS married UNION ALL

SELECT 54, 124, 1 UNION ALL

SELECT 31, 124, 0 UNION ALL

SELECT 32, 95, 0 UNION ALL

SELECT 74, 34, 0 UNION ALL

SELECT 18, 56, 0 UNION ALL

SELECT 43, 42, 0 UNION ALL

SELECT 78, 56, 0 UNION ALL

SELECT 91, 77, 1

)

SELECT age, iq, married

FROM People p1

WHERE EXISTS (SELECT 1 FROM People p2 WHERE p1.iq = p2.iq AND p2.married = 1);