if MOD(l_enable,2) = 1 then -- to do set work
l_temp :=TRUNC(l_outvalue/POWER(2,j));
if MOD (l_temp,2) = 0 then -- set it to 1
l_outvalue := l_outvalue + POWER(2,j);
end if;
end if;
l_enable := TRUNC(l_enable/2);
j := j+1 ;
end loop;
-- disable
j := 0;
while l_disable > 0 loop
if MOD(l_disable,2) = 1 then -- to do set work
l_temp :=TRUNC(l_outvalue/POWER(2,j));
if MOD (l_temp,2) = 1 then -- set it to 0
l_outvalue := l_outvalue - POWER(2,j);
end if;
end if;
l_disable := TRUNC(l_disable/2);
j := j+1 ;
end loop;
return l_outvalue;
end;
/
2. func_and
用于对两个数进行与操作,经常用于判断用户是否有权限等。
create or replace function func_and(in_value IN NUMBER,in_mask IN NUMBER)
return number is
i number;
n_result number;
n_value number;
n_mask number;
begin
n_value := in_value;
n_mask := in_mask;
i := 0;
n_result := n_value;
while n_value > 0 loop
if (mod(n_mask,2) = 0) and (mod(n_value,2) = 1) then
n_result := n_result - power(2,i);
end if;
n_value := TRUNC(n_value/2);
n_mask := TRUNC(n_mask/2);
i := i + 1;
end loop;
return n_result;
end;
/