Question

I am writing a postgresql function but I cannot seem to find where the error is. Postgresql is at version 9.4.
The following is the function:

CREATE FUNCTION custom_function1()
RETURNS trigger
LANGUAGE plpgsql
AS
$$
    DECLARE base_val integer;
    BEGIN
        base_val := (EXTRACT(YEAR FROM now())::integer * 10000000000);

        IF (currval('custom_sequence') < base_val) THEN
            setval('custom_sequence', base_val);
        END IF;

        NEW.id := custom_function2();
        RETURN NEW;
    END;
$$;

My custom_sequence is in the format YYYY0000000000 (ex. 20150000000000).

So what this basically does (should do) is it checks if the base_val (minimum value for current year) is greater then the currval (current custom_sequence value) and updates the custom_sequence value. Then it returns a new value for that sequence generated with the function custom_function2 (which formats it slighly).

When I try to execute this it gives me:
syntax error at or near "setval"
I am pretty new to both postgresql and writing functions so I am probably not seeying an obvious error. If someone could help me it would be highly appreciated, thank you.

Answer 1

The error is related to what's explained in the doc here:

40.5.2 Executing a Command With No Result
[...]

Sometimes it is useful to evaluate an expression or SELECT query but discard the result, for example when calling a function that has side-effects but no useful result value. To do this in PL/pgSQL, use the PERFORM statement:

PERFORM query;

You should write:

PERFORM setval('custom_sequence', base_val);

postgresql function creation gives syntax error

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