Hello
2011/3/2 Pierre Racine <Pierre.Racine@sbf.ulaval.ca>:
> Hi,
>
> I would like to write a generic plpgsql function with a text parameter being a callback function name so that my
generalfunction can call this callback function. e.g.:
>
> CREATE OR REPLACE FUNCTION ST_MyCallbackFunction(y int)
> RETURNS int AS $$
> DECLARE
> BEGIN
> RETURN someCalculationBasedOnY;
> END;
> $$ LANGUAGE 'plpgsql';
>
> CREATE OR REPLACE FUNCTION ST_MyGeneralFunction(callback text)
> RETURNS SETOF geomval AS $$
> DECLARE
> x integer;
> y integer;
> BEGIN
> y := somecalculation;
> x := 'callback'(y); --This is what I need
EXECUTE 'SELECT ' || callback || '($1)' USING y INTO x;
there are no other way than EXECUTE
attention - there is a sql injection risk
regards
Pavel Stehule
> RETURN x;
> END;
> $$ LANGUAGE 'plpgsql';
>
> I don't want to do an EXECUTE statement since I have no table to put after the FROM clause. I want to assign the
resultingvalue directly to a variable like in my example.
>
> Can I/How can I achieve this?
>
> Thanks,
>
> Pierre
>
>
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