Peter Sobieraj

Today I was fighting with strange error.

 
SELECT
  -- ...
  (
  (SELECT SUM(t.v)
   FROM tab1 t
   )
  +
  (SELECT SUM(t.v)
   FROM tab2 t
   )
  ) AS x
-- ...
 

Something like that give me NULL in x in every row even if there was a lot of records in tab1. (more…)