function中的一个语句
JS 2012-04-11 10:45:51 CREATE FUNCTION "tab"."F_PERCENT" (
"P" DECIMAL(16,10),
"D" INTEGER )
RETURNS CHARACTER(20)
SPECIFIC "SQL120401142999999"
LANGUAGE SQL
NOT DETERMINISTIC
EXTERNAL ACTION
READS SQL DATA
CALLED ON NULL INPUT
INHERIT SPECIAL REGISTERS
begin ATOMIC
declare c char(20);
set c=(
select case when p>=0.01 then
trim(T '.' from trim(B '0' from trim(char(round(p*100,d)))))||'%'
else '0'||trim(T '.' from trim(B '0' from trim(char(round(p*100,d)))))||'%'
end
from SYSIBM.SYSDUMMY1
);
return c;
end;
trim里面的用法让我无法理解,请高人指点