plpgsql function return another function value

Question

I have a function func1() which returns integer.

I want to write another function func2(mode integer) which can return func1() reults or do some more stuff. The return value of func1() is of type INTEGER.

something like this:

CREATE OR REPLACE FUNCTION func2(mode integer)
  RETURNS integer AS
$$
begin
     if mode=1 then
       return func1();  -- NOT plpgsql syntax
     end if;

     more stuff .....

     return 2;
end
$$
LANGUAGE plpgsql VOLATILE

my question is how to do return func1(); ?

I know I can do :

select func1() into temp;
return temp;

but I was wondring if there is a more elegent way to do that.

`return func1();` works for me: http://sqlfiddle.com/#!15/18442/1 What is the error you get? — , Sep 06 '16 at 11:12

score 1 · Accepted Answer · answered Sep 06 '16 at 11:35

1

All of these work:

Option 1:

CREATE OR REPLACE FUNCTION func2(mode integer)
    RETURNS integer AS
$BODY$
DECLARE 
    _result integer;
BEGIN
    _result = 2;
     IF mode=1 THEN
       _result = func1();
     END IF;

     --more stuff .....

     RETURN _result;
END
$BODY$
    LANGUAGE plpgsql VOLATILE COST 100;

Option 2:

CREATE OR REPLACE FUNCTION func2(mode integer)
    RETURNS integer AS
$BODY$
BEGIN
     IF mode=1 THEN
       RETURN func1();
     END IF;

     --more stuff .....

     RETURN 2;
END
$BODY$
    LANGUAGE plpgsql VOLATILE COST 100;

answered Sep 06 '16 at 11:35

Boris Schegolev

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Using `:=` as the assignment operator is preferred over the simple `=` – Sep 06 '16 at 11:37
@a_horse_with_no_name why is it prefered? – ban Sep 06 '16 at 11:42
I never liked the Pascal notation. Just a personal preference :) – Boris Schegolev Sep 06 '16 at 11:42
Up until 9.3 this was actually the only documented assignment operator: https://www.postgresql.org/docs/9.3/static/plpgsql-statements.html a simple equal sign was nevertheless accepted. – Sep 06 '16 at 11:48
@a_horse_with_no_name but if both = and := are acceptable. Why did you say that := is prefered? Prefered for what reason? – ban Sep 06 '16 at 12:11
@ban: This related answer provides some background for `=` vs. `:=` in plpgsql: http://stackoverflow.com/a/22001209/939860 – Erwin Brandstetter Sep 07 '16 at 02:06
1

@ban - "=" is logical operator, ":=" is assign statement. Some languages that using "=" for assigning use different symbol for equivalence. PLpgSQL has some limits against origin ADA so this difference doesn't play big role, but better to be consistent with original language - the possibility to use "=" for assignment is bug, but it is too late to fix it. – Pavel Stehule Sep 08 '16 at 03:46

plpgsql function return another function value

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