>Hi
>
>I have a IB_Query that some fields returned are "calculated" by case
>expression and of course these columns have dedicated aliast.
>When I want to filter this query using Filter property like
>"A_CASE_COLUMN = SOME_VALUE' I'm getting exception saying that
>A_CASE_COLUMN is unknown column.
>Is there a way to apply local filtering other than OnFilterRecord event?

This is not a direct answer to your question, Marcin, but adding a CTE is maybe a possible workaround (I haven't tried). I.e. rather than

SELECT a, case when a < 5 then b else c end as bc
FROM MyTable

you could try

WITH TMP(a, bc) as
(SELECT a, case when a < 5 then b else c end
FROM MyTable)
SELECT * FROM TMP

HTH,
Set