invalid input syntax for integer: "NULL"

On 02/20/2007 03:45:55 PM, Yonatan Ben-Nes wrote:

Hi everyone,

I'm trying to write a PL/pgSQL function which execute an insert, I
encounter
a problem when I try to insert NULL value into an integer field.

RETURN 'INSERT INTO test (bh) VALUES ('||COALESCE(intornull,
'NULL')||')';

And if I try to change the COALESCE second value at the function to
NULL
(instead of 'NULL') it works if a value is being passed to the
integer field
but doesn't work if a NULL Is passed:

NULL, without the quotes, is the proper way to write
NULL as a literal value. When you put quotes around it it's a
string. So that's why you get a type exception.

COALESCE chooses the first value that's not NULL. So if you
pass it NULL you may as well not supply the second argument.

You probably want a plpgsql IF statement or a CASE expression.

Karl <kop@meme.com>
Free Software: "You don't pay back, you pay forward."
-- Robert A. Heinlein

On Tue, 20 Feb 2007, Yonatan Ben-Nes wrote:

Hi everyone,

I'm trying to write a PL/pgSQL function which execute an insert, I encounter
a problem when I try to insert NULL value into an integer field.
The following code is for reproducing:

CREATE TABLE test(
bh INT8
);

CREATE OR REPLACE FUNCTION testinsertion(intornull bigint) RETURNS text AS
$$
DECLARE
BEGIN
RETURN 'INSERT INTO test (bh) VALUES ('||COALESCE(intornull, 'NULL')||')';

I think you'd need something like
COALESCE(CAST(intornull AS TEXT), 'NULL')
in order to make that work. You want the output to effectively be a string
which contains the int to be concatenated with the other strings or the
string 'NULL' to be concatentated with the other strings.