On Jun 7, 2008, at 2:58 AM, Ralph Smith wrote:
CODE:
===============================
CREATE OR REPLACE FUNCTION find_next_delim(invar varchar, delimlist
varchar) RETURNS integer AS
$$
/* OVERLOADED Function. The other version takes a 3rd parameter
as the
starting position in invar.
*/
DECLARE
achar character := '' ;
It's because you're using character here instead of text. Character
collapses whitespace (it's usually used as char(<some length>). To
demonstrate:
development=> select ''''||CAST (' '::character AS text)||'''';
?column?
----------
''
So your comparison becomes:
development=> SELECT strpos('3', '');
strpos
--------
1
Now that's got to be a corner case of the use of strpos, I'm not
entirely sure that'd be the right behaviour, but if it isn't, what
would be? Does a non-empty string contain empty strings? And if so,
is it at position 1? The character at position 1 is actually '3'
after all... Maybe it should return NULL (unknown) or raise an error?
When using text instead of character, your function works as expected.
j int := 0 ;
BEGIN
IF length(delimlist) = 0 THEN
RAISE NOTICE 'In function \'find_next_delim\' the delimiter
cannot be null.' ;
An empty string is not null. If someone would actually enter NULL for
delimlist your function would break:
development=> select find_next_delim(NULL,'3') ;
ERROR: upper bound of FOR loop cannot be NULL
CONTEXT: PL/pgSQL function "find_next_delim" line 18 at FOR with
integer loop variable
END IF ;
FOR i IN 1 .. length(invar)
LOOP
j := j + 1 ;
achar := substring(invar from i for 1 ) ;
RAISE NOTICE 'achar is R%S',achar ;
IF strpos(delimlist,achar) <> 0 THEN
RETURN j ;
END IF ;
END LOOP ;
RETURN 0 ;
END ;
$$ LANGUAGE plpgsql ; /* find_next_delim */
WHAT'S HAPPENING:
===============================
airburst=# select find_next_delim('ralph smith','3') ;
NOTICE: achar is RrS
NOTICE: achar is RaS
NOTICE: achar is RlS
NOTICE: achar is RpS
NOTICE: achar is RhS
NOTICE: achar is R S
find_next_delim
-----------------
6
(1 row)
airburst=# select find_next_delim('ralph smith','') ; -- for the
heck of it, that's a null
NOTICE: In function 'find_next_delim' the delimiter cannot be null.
NOTICE: achar is RrS
NOTICE: achar is RaS
NOTICE: achar is RlS
NOTICE: achar is RpS
NOTICE: achar is RhS
NOTICE: achar is R S
find_next_delim
-----------------
6
(1 row)
WHY find a match on the space???
Thanks!
Alban Hertroys
--
If you can't see the forest for the trees,
cut the trees and you'll see there is no forest.
!DSPAM:737,484a5f1e927662100280104!
