Código SQL:
Ver originalSELECT t2.nombre AS nombre_nivel, t3.nombre AS nombre_grade, t4.nombre AS nombre_seccion FROM relaciones AS t1
INNER JOIN niveles AS t2 ON (t1.id_nivel=t2.id_nivel)
INNER JOIN grados AS t3 ON (t1.id_grado=t3.id_grado)
INNER JOIN secciones AS t4 ON (t1.id_seccion=t4.id_seccion)