Question

问题是，循环没有根据需要进行计数：

我需要举例：100％的DVD价格等于64 $ 95％是60.8 $ 在90时，它必须取原始价格（64 $）并从该价格中赚取90％，但是，他从最近的价格（60.8 $）开始计算，而他在做90％。

create or replace procedure PR_PRICE
is V_PRICE DVD.AMOUNT_PRICE_DVD%type;
p_counter number(3):=100;
begin
    select AMOUNT_PRICE_DVD into V_PRICE
    from DVD
    where TITLE_DVD like '%pop';
 --   p_counter :=100;

    while p_counter >= 80 loop
        V_PRICE := p_counter*V_PRICE/ 100;

        dbms_output.put_line('The price of DVD at ' || p_counter ||'% is: ' ||  V_PRICE ||'$');
        p_counter := p_counter-5;
    end loop;


end PR_PRICE;
/

Answer 1

而不是覆盖v_price，而是为折后价格创建一个不同的变量：

create or replace procedure PR_PRICE
is 
V_PRICE DVD.AMOUNT_PRICE_DVD%type;
V_DISCOUNT_PRICE DVD.AMOUNT_PRICE_DVD%type; -- Declared here
p_counter number(3):=100;
begin
    select AMOUNT_PRICE_DVD into V_PRICE
    from DVD
    where TITLE_DVD like '%pop';

    p_counter :=100;

    while p_counter >= 80 loop
        V_DISCOUNT_PRICE := p_counter*V_PRICE/ 100; -- Calculated here

        dbms_output.put_line('The price of DVD at ' || p_counter ||'% is: ' ||  V_DISCOUNT_PRICE ||'$');
        p_counter := p_counter-5;
    end loop;


end PR_PRICE;

使用while的PL / SQL循环

1 个答案: