how to add different record values?

Question

I’m trying to add the value of id 1 and the value2 of id 2 which in this case would be equal to 220, as I do this consultation?

       ID      VALOR     VALOR2
---------- ---------- ----------
         1        110        100
         2        100        110

this was the select I was trying to, but not the right one

select valor+valor2 from teste3 where valor = (select valor from teste3 where id = 1 and valor2 = (select valor2 from teste3 where id = 2))

Answer 1

SELECT SUM(x.valor) AS total
  FROM (
    SELECT valor FROM teste3 WHERE id = 1
    UNION ALL
    SELECT valor2 FROM teste3 WHERE id = 2
  ) x;