Add a 'Virtual' column to a SELECT in Oracle

Question

I would like to place a temporary column that was generated only in the query that will be linked to CD_NIVEL say, "If CD_NIVEL = 5 creates a column 'Exclui' as if it were a description of what the 5 means, I searched here and I found nothing I am new and I am learning SQL.

SQL code:

   select  a.cd_usuario
,       (select nm_usuario from adm_usuario where cd_usuario=a.cd_usuario and cd_empresa=a.cd_empresa) as ds_usuario 
,       (select cd_funcionario from adm_usuario where cd_usuario=a.cd_usuario and cd_empresa=a.cd_empresa) as ds_funcionario
,       a.cd_empresa
,       a.cd_componente
,       a.cd_nivel
from ADM_USUCMPEMP a
where cd_nivel=5 
and (select tp_privilegio from adm_usuario where cd_usuario=a.cd_usuario and cd_empresa=a.cd_empresa)='1' 
and (select tp_bloqueio from adm_usuario where cd_usuario=a.cd_usuario and cd_empresa=a.cd_empresa)=0 
--and a.cd_usuario=6029 
and a.cd_empresa=90 
--and a.cd_componente like '%FISR031%'
order by 5

Answer 1

You can use the CASE to achieve this in your select. Example on this link.

SELECT 
    a.cd_usuario,
    ...
    a.cd_nivel, 
    CASE
        WHEN a.cd_nivel = 5
        THEN 'Exclui'
    END AS DescNivel
FROM
    ...

Remembering that the other values will have value null in that column.