Hi,
four years ago Marko Tiikkaja send a patch for numeric_trim functions. This functions removed ending zeroes from numeric value. This is useful feature, but there was not any progress on this patch. I think so this feature can be interesting, so I would to revitalize this patch.
Based on this discussion I would to implement three functions - prototype implementation is in plpsql and sql - final implementation will be in C.
-- returns minimal scale when the rounding the value to this scale doesn't
-- lost any informations.
CREATE OR REPLACE FUNCTION pg_catalog.minscale(numeric)
RETURNS integer
LANGUAGE plpgsql
AS $function$
begin
for i in 0..256
loop
if round($1, i) = $1 then
return i;
end if;
end loop;
end;
$function$
-- trailing zeroes from end
-- trimming only zero for numeric type has sense
CREATE OR REPLACE FUNCTION pg_catalog.rtrim(numeric)
RETURNS numeric AS $$
SELECT round($1, pg_catalog.minscale($1))
$$ LANGUAGE sql;
-- this is due support trim function
CREATE OR REPLACE FUNCTION pg_catalog.btrim(numeric)
RETURNS numeric AS $$
SELECT pg_catalog.rtrim($1)
$$ LANGUAGE sql;
postgres=# select trim(10.22000);
┌───────┐
│ btrim │
╞═══════╡
│ 10.22 │
└───────┘
(1 row)
postgres=# select rtrim(10.34900);
┌────────┐
│ rtrim │
╞════════╡
│ 10.349 │
└────────┘
(1 row)
What do you think about it?
Regards
Pavel
