Although the following code is correct from the syntax point of view, it doesn't work:
create or replace function f_getDateType (in_dt DATE)
return VARCHAR2
is
v_out VARCHAR2(10);
begin
case TO_CHAR(in_dt,'d')
when null then
-- value will be null if in_dt is null
v_out:='';
when 1 then
v_out:='SUNDAY';
when 7 then
v_out:='SATURDAY';
else
v_out:='WEEKDAY';
end case;
return v_out;
end;
/