Re: Referencing function value inside CASE..WHEN

Hello

2011/6/19 lover boi <lover-boi(at)live(dot)co(dot)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.