创建函数样例
create or replace procedure function_procedure
AS
i_count integer;
begin
select count(*) into i_count from user_objects t where t.OBJECT_TYPE ='FUNCTION' and t.OBJECT_NAME = upper('function_name');
if i_count>0 then
EXECUTE IMMEDIATE 'drop function function_name';
end if;

end init_function_procedure;
/
call function_procedure();
drop procedure function_procedure;

create or replace function function_name(type in INTEGER) return number is
result number;
begin
if(type=1) then
result:=300/100;
elsif (type=2) then
result:=300/200;
elsif (type=3) then
result:=300/300;
end if;

return(result);
end function_name;
/