WHEN NO_DATA_FOUND THEN....

I have a properly working function that looks like this:

create or replace function get_lang_id(p_lname varchar(150)) returns
int as
$$
DECLARE
p_lang_id int;
BEGIN
select lang_id into p_lang_id
from languages
where language=p_lname;
if (p_lang_id is null) then
p_lang_id=0;
end if;
return(p_lang_id);
END;
$$
LANGUAGE plpgsql;

Why am I writing this post? Well, it seems strange to me that the query

select lang_id into p_lang_id
from languages
where language=p_lname;

will quietly return NULL if the data is not found. Is that behavior
compliant with the standard? I must confess being used to the code like
this:

1 create or replace function get_lang_id(p_lname varchar2)
2 return integer as
3 p_lang_id integer;
4 begin
5 select lang_id into p_lang_id
6 from languages
7 where language=p_lname;
8 return(p_lang_id);
9 exception
10 when NO_DATA_FOUND then
11 return(0);
12* end;
SQL> /

Function created.

Elapsed: 00:00:00.38
SQL> select get_lang_id('Martian') from dual;

GET_LANG_ID('MARTIAN')
----------------------
0

Elapsed: 00:00:00.10

Is there any way for Postgres to raise an exception when no data is
found? I really like exceptions, they make it possible for me to handle
all of the errors in one place, without those pesky "if" clauses. Just
to make sure that I am understood, Oracle's behavior is even worse,
without the exception handler it will quietly return NULL, without any
errors.

--

Mladen Gogala
Sr. Oracle DBA
1500 Broadway
New York, NY 10036
(212) 329-5251
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