oracle - pl/sql中数字的阶乘

Question

下面的pl/sql程序在执行sum sum == temp * sum;时会生成错误。遇到符号;期待时(。请解释我的错误。

declare
  n number;
  temp number;
  sum number := 1;
begin
  n := &n;
  temp := n;
  while temp>0 loop
    sum := temp*sum;
    temp := temp-1;
  end loop;
  dbms_output.put_line('Factorial of '||n||' is '||sum);
end;
/

Answer 1

Sum是sql中的保留字。像这样更改变量名称

declare
  n number;
  temp number;
  sum_ number := 1;
begin
  n := &n;
  temp := n;
  while temp>0 loop
    sum_ := temp*sum_;
    temp := temp-1;
  end loop;
  dbms_output.put_line('Factorial of '||n||' is '||sum_);
end;
/