select tca.idregistro as idarea, tca.nombre as area,
tc.idregistro as idcongreso, tc.nombre as congreso
from esq_conv_2020.tbl_congreso tc
join esq_conv_2020.tbl_convencion_area tca on tca.idregistro = tc.id_area
where tc.id_convencion = 9
order by tca.nombre , tc.nombre