Hello
2011/6/19 lover boi <lover-boi@live.co.uk>:
> Hi,
>
> In the following statement, does the custom function get executed twice?
>
> SELECT
> MY_FUNCTION(...),
> CASE WHEN MY_FUNCTION(...) = '...' THEN '...' ELSE '...' END
> ...
> ...
>
>
> If so, is there a way I can make it execute once? I tried this but it gave
> me a "Column my_function does not exist" error.
>
SELECT x, CASE WHEN x THEN .. ELSE .. END FROM (SELECT fce(..) x FROM foo) s;
Regards
Pavel Stehule
> SELECT
>
> MY_FUNCTION(...) AS my_function,
>
> CASE WHEN my_function = '...' THEN '...' ELSE '...' END
>
> ...
>
> ...
>
>
> Thank you in advance.