[GENERAL] Two variable passed to PL/Function and on is NULL

Dear All,

I have written a PL/pgSQL fucntion which takes two arguments and returns a
boolean on the basis of a few (string) comparaisons.

The function works fine as long as BOTH passed variables are non-NULL but
behaves strangely if one of the variables is non-NULL.

Looking at previous postings, I found:

>Very observant of you. The postgres function system doesn't have a way
>to tell which parameter is null, so the function just returns null.
>I don't like it and we hope to get it changed for PGv6.5 (at least I
>do).

Now that example was with a 'c' function but presumably, function are
handled the same way internally whatever the function language?

SO my question are:

i) Is it the case that if you pass to variables to a postgres function and
one is NULL, the function cannot tell which one?
ii) Is there a workaround of some kind (in particular in pl/pgsql)?
[Currently I am copying the table into a temp table and updating all NULL
values to a token value.]

regards,

Stuart.

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| Stuart Rison | Ludwig Institute for Cancer Research |
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