Question

显示用户ID，用户名，总金额，折扣后支付的金额，并将别名命名为User_ID，user_name，Total_amount，Paid_amount。按用户ID降序显示记录。点击TABLE SHCEMA获取表格

这是我写的代码。但这并没有显示出预期的结果：

SELECT 
    USERS.USER_ID AS User_ID,
    NAME AS user_name,
    (FARE * NO_SEATS) AS Total_amount 
FROM 
    USERS 
INNER JOIN 
    TICKETS ON USERS.USER_ID = TICKETS.USER_ID 
INNER JOIN 
    PAYMENTS ON TICKETS.TICKET_ID = PAYMENTS.TICKET_ID 
INNER JOIN 
    DISCOUNTS ON PAYMENTS.DISCOUNT_ID = DISCOUNTS.DISCOUNT_ID 
GROUP BY 
    USERS.USER_ID, NAME, FARE, NO_SEATS
ORDER BY 
    USERS.USER_ID DESC;

这是预期的输出：

USER_ID USER_NAME   TOTAL_AMOUNT   PAID_AMOUNT
----------------------------------------------
 5       Krena           700         625
 4       Johan           800         775
 3       Ivan           3000        2900
 1       John           4000        3950
 1       John           4000        3950
 1       John           2000        1900

Answer 1

试试这段代码。

SELECT 
USERS.USER_ID AS USER_ID,
USERS.NAME AS USER_NAME,
(TICKETS.FARE * TICKETS.NO_SEATS) AS TOTAL_AMOUNT,
(TICKETS.FARE * DISCOUNTS.DISCOUNT_AMOUNT) + TICKETS.FARE AS PAID_AMOUNT 
FROM 
USERS USERS
INNER JOIN TICKETS TICKETS
        ON USERS.USER_ID=TICKETS.USER_ID 
INNER JOIN PAYMENTS PAYMENTS
        ON TICKETS.TICKET_ID=PAYMENTS.TICKET_ID 
INNER JOIN DISCOUNTS DISCOUNTS
        ON PAYMENTS.DISCOUNT_ID=DISCOUNTS.DISCOUNT_ID 
ORDER BY USERS.USER_ID DESC;

我在数据库结构中感到困惑，为什么它在数字数据类型中呢？您可能想要将其更改为十进制，并将其长度设置为（11,2），因为我假设您的折扣金额中的折扣金额是百分比吗？或者只是将示例数据库粘贴到此处，以便我可以更新我的代码。

Answer 2

如果我有足够的声誉，我会把它写成评论（叹息）：你还没有明确定义你的预期结果。

我假设以下内容：

打印用户的总金额，包括Total_amount（即官方价格），Paid_amount（即折扣后），因此它将包括所有门票及其付款。
我认为折扣是从展会上扣除的正数，是每1个席位

那么这应该可以解决问题：

SELECT 
  USER_ID AS USER_ID,
  NAME AS USER_NAME,
  sum(FARE * NO_SEATS) AS TOTAL_AMOUNT,
  sum((FARE - DISCOUNT_AMOUNT ) * NO_SEATS) AS PAID_AMOUNT 
FROM USERS u
INNER JOIN TICKETS t
        ON u.USER_ID=t.USER_ID 
INNER JOIN PAYMENTS p
        ON t.TICKET_ID=p.TICKET_ID 
INNER JOIN DISCOUNTS d
        ON p.DISCOUNT_ID=d.DISCOUNT_ID 
group by USER_ID, name
ORDER BY USER_ID DESC;

Answer 3

这将有效，请尝试

SELECT 
USERS.USER_ID AS USER_ID,
USERS.NAME AS USER_NAME,
(TICKETS.FARE * TICKETS.NO_SEATS) AS TOTAL_AMOUNT,
(TICKETS.FARE * TICKETS.NO_SEATS - DISCOUNTS.DISCOUNT_AMOUNT) AS PAID_AMOUNT 
FROM 
USERS 
INNER JOIN TICKETS 
        ON USERS.USER_ID=TICKETS.USER_ID 
INNER JOIN PAYMENTS
        ON TICKETS.TICKET_ID=PAYMENTS.TICKET_ID 
INNER JOIN DISCOUNTS
        ON PAYMENTS.DISCOUNT_ID=DISCOUNTS.DISCOUNT_ID 
ORDER BY USERS.USER_ID DESC;

Answer 4

这是该问题的正确答案，可以给出准确的输出结果

use-attribute-sets

Answer 5

将查询写入

显示用户ID，用户名，票证ID，总金额，待付款金额折扣后付款，并给别名提供用户名，用户名，票证编号，总金额，已付款金额。以降序显示记录按用户ID排序。

避免重复记录。

[注意：要支付的总金额应为机票数量*每张机票的金额]

此代码运行100％

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SQL查询生成以下输出

5 个答案: