UPDATE fb
  SET fb.C_FELHASZNALOID = f.ID
FROM T_FELHASZNALOBELEPES fb
  INNER JOIN (
    SELECT ID, C_INTEZMENYID, C_TANEVID
    FROM T_FELHASZNALO
    WHERE C_TANEVID IN (
    SELECT ID
    FROM T_TANEV
    WHERE C_AKTIV = 'F'
      AND (C_KOVETKEZO = 'T' OR C_KOVETKEZO IS NULL))
      AND C_UTONEV = 'Adminisztrátor') f ON f.C_INTEZMENYID = fb.C_INTEZMENYID
        AND f.C_TANEVID = fb.C_TANEVID
WHERE fb.C_TANEVID IN (SELECT ID
FROM T_TANEV 
WHERE C_AKTIV = 'F'
  AND (C_KOVETKEZO = 'T' OR C_KOVETKEZO IS NULL))
  AND C_BEJELENTKEZESINEV = 'admin'
GO