plPGSQL bug in function creation

On Monday 08 September 2003 09:32, Marek Lewczuk wrote:

Hello,
I think that there is a bug in plPGSQL - or maybe I don't know something
about this language. Try to create this function

[snip]

And when i execute: SELECT test(NULL, 'buuu'); -> it returns me NULL
value, when it should return "buuu". Well I think that something is
wrong here.

If I will modify this function again to this:

CREATE FUNCTION "public"."test" (varchar, varchar) RETURNS text AS'

[snip]

Everything is working OK.. So the problem is in TEXT type definition.

I'm using PG 7.3.1 on Win/Cyg

Can't reproduce here:

CREATE OR REPLACE FUNCTION functest1(varchar, varchar) RETURNS varchar AS '
BEGIN
IF $1 THEN
RETURN $1;
ELSE
RETURN $2;
END IF;
END;
'LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

CREATE OR REPLACE FUNCTION functest2(text, text) RETURNS varchar AS '
BEGIN
IF $1 THEN
RETURN $1;
ELSE
RETURN $2;
END IF;
END;
'LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

SELECT functest1('A','B'), functest1(null,'B'), functest2('A','B'),
functest2(null,'B');

CREATE FUNCTION
CREATE FUNCTION
functest1 | functest1 | functest2 | functest2
-----------+-----------+-----------+-----------
A | B | A | B
(1 row)

richardh=# select version();
version
-------------------------------------------------------------
PostgreSQL 7.3.2 on i686-pc-linux-gnu, compiled by GCC 2.96

Not sure whether this is because of the change 7.3.1->7.3.2 or cygwin vs
linux. Don't have a copy of 7.3.1 to check against, sorry. Perhaps check the
changes list to see if it mentions something like this.

--
Richard Huxton
Archonet Ltd

I had the same success using 7.3.2 with Cygwin:

e=# SELECT functest1('A','B'), functest1(null,'B'), functest2('A','B'),
functest2(null,'B');

functest1 | functest1 | functest2 | functest2
-----------+-----------+-----------+-----------
A | B | A | B
(1 row)

e=# select version();
version
----------------------------------------------------------------------------
----------
PostgreSQL 7.3.2 on i686-pc-cygwin, compiled by GCC gcc (GCC) 3.2 20020927
(prerelease)
(1 row)

George

- snip -

Not sure whether this is because of the change 7.3.1->7.3.2 or cygwin vs
linux. Don't have a copy of 7.3.1 to check against, sorry. Perhaps check

the

Marek Lewczuk wrote:

Hello,
I think that there is a bug in plPGSQL - or maybe I don't know something
about this language. Try to create this function

Ok., this is the function created in plPGSQL:

CREATE FUNCTION "public"."test" (text, text) RETURNS text AS'
BEGIN
IF $1 THEN
RETURN $1;
ELSE
RETURN $2;
END IF;
END;
'LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

If you will execute SELECT test('tess', 'erer') -> then "tess" will be
returned. If you will execute: SELECT test(NULL, 'buuu'); -> then it
will return NULL, but it should return "buuu". I tried to figure out why
it is happening so i modifye this function to this:

CREATE FUNCTION "public"."test" (text, text) RETURNS text AS'
BEGIN
RETURN 'test';
END;
'LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

And when i execute: SELECT test(NULL, 'buuu'); -> it returns me NULL
value, when it should return "buuu". Well I think that something is
wrong here.

If I will modify this function again to this:

CREATE FUNCTION "public"."test" (varchar, varchar) RETURNS text AS'
BEGIN
IF $1 THEN
RETURN $1;
ELSE
RETURN $2;
END IF;
END;
'LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

Everything is working OK.. So the problem is in TEXT type definition.

I'm using PG 7.3.1 on Win/Cyg

---------------------------(end of broadcast)---------------------------
TIP 8: explain analyze is your friend

You can only test for NULL with 'IS NULL'.

NULL is NOT:
FALSE, 0, or F

"Marek Lewczuk" <newsy@lewczuk.com> writes:

CREATE FUNCTION "public"."test" (text, text) RETURNS text AS'
BEGIN
IF $1 THEN
RETURN $1;
ELSE
RETURN $2;
END IF;
END;
'LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

If there's a bug here at all, it's that this function doesn't report a
type violation. What in the world do you think the semantics of that
IF-test are? text is not boolean.

regards, tom lane