Re: string concatenation

Gyorgy Molnar wrote:
> plase take a look to the following small sample
>
> CREATE FUNCTION test(TEXT) RETURNS TEXT AS '
> DECLARE
> cmd TEXT;
> BEGIN
> RETURN cmd || ''Hello'';
> END;
> ' LANGUAGE 'plpgsql';
>
> When I execute the function
>
> select test('');
> test
> ------
>
> (1 row)
>
> I got an empty string for result. I think I got this result because the
> string concatenation ("||") was created with "isstrict" flag. In this case
> it will give back NULL object if one of the arguments was NULL object.
>
> In most of the cases I think it is ok, but specially for the string
> concatenation is not really convinient.
>
> Is this feature will change in the future? Any "smart" solution for this
> problem? - I cannot use the IF..ENDIF statement before each string
> concatenation, I have too many in my code.

The function in incorrect. cmd is NULL because you haven't used $1.
Try:

test=> CREATE FUNCTION test2(TEXT) RETURNS TEXT AS '
test'> BEGIN
test'> RETURN $1 || ''Hello'';
test'> END;
test'> ' LANGUAGE 'plpgsql';
CREATE FUNCTION
test=> select test2('a');
test2
--------
aHello
(1 row)

test=> select test2('');
test2
-------
Hello
(1 row)

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