CREATE OR REPLACE FUNCTION removeTurmasComMenosDe(n int4)
 RETURNS VOID AS
 $$
 DECLARE
  TUPLA record;
 BEGIN
  FOR TUPLA IN
   SELECT TU.ID, COUNT(FR.ID_EST) AS QTD_ALUNOS
   FROM TURMA AS TU LEFT OUTER JOIN FREQUENTA AS FR ON TU.ID = FR.ID_TURMA
   GROUP BY TU.ID
   ORDER BY QTD_ALUNOS
  LOOP
   IF TUPLA.QTD_ALUNOS <= n THEN
    DELETE FROM FREQUENTA WHERE ID_TURMA = TUPLA.ID;
    DELETE FROM ENSINA WHERE ID_TURMA = TUPLA.ID;
    DELETE FROM HORARIO_AULA WHERE ID_TURMA = TUPLA.ID;
    DELETE FROM TURMA WHERE ID = TUPLA.ID;

   END IF;
  END LOOP;

 END;

 $$ LANGUAGE 'PLPGSQL';