select tc.nombre as congreso,
upper(concat(tpe.apellido1,' ',tpe.apellido2,' ',tpe.nombres)) as asistente,
tpe.correo
from esq_conv_2020.tbl_preinscripcion tp
join esq_conv_2020.tbl_congreso tc on tc.idregistro = tp.id_congreso
join esq_conv_2020.tbl_personal_ext tpe on tpe.idregistro = tp.id_personal_tmp
where tc.id_convencion = 9
order by tc.nombre , asistente