mysql 通过将位于两个单独表中的price和quantity列相乘来计算餐馆数据库中每个订单的总价

abithluo  于 2023-03-07  发布在  Mysql
关注(0)|答案(2)|浏览(128)

我有两张表:Contain和FoodItem。它们的说明和内容如下所示。

CREATE TABLE Customer (
CustomerID INT NOT NULL AUTO_INCREMENT,
Fname VARCHAR(10),
Lname VARCHAR(10), 
PRIMARY KEY (CustomerID)
);

CREATE TABLE Orders (
OrderNo INT NOT NULL AUTO_INCREMENT,
OrderDate DATETIME NOT NULL, 
CustomerID INT,
PRIMARY KEY (OrderNo),
FOREIGN KEY (CustomerID) REFERENCES Customer(CustomerID)
);

CREATE TABLE FoodInfo (
ItemName VARCHAR(10) NOT NULL,
Description VARCHAR(10),
PRIMARY KEY (ItemName)
);

CREATE TABLE FoodItem (
ItemName VARCHAR(10),
OrderNo INT,
Price SMALLINT,
PRIMARY KEY (ItemName, OrderNo),
FOREIGN KEY(OrderNo) REFERENCES Orders (OrderNo),
FOREIGN KEY(ItemName) REFERENCES FoodInfo (ItemName)
);

CREATE TABLE Contain(
    OrderNo INT,
    ItemName VARCHAR(10),
    Quantity INT,
    PRIMARY KEY(OrderNo, ItemName),
    FOREIGN KEY(OrderNo) REFERENCES Orders (OrderNo),
    FOREIGN KEY(ItemName) REFERENCES FoodInfo (ItemName)
    );

INSERT INTO Customer VALUES
(1, Velda, Quigley),
(2, Abelardo, Stoltenber),
(3, Ludwig, Dare),
(4, Jordan, Beahan),
(5, Saul, Rohan),
(6, Una, Bergnaum),
(7, Richie, Bauch),
(8, Rubie, Gibson),
(9, Holden, Nader),
(10, Lance, Jacobi);


INSERT INTO Orders VALUES 
(2019-10-09 01:22:26, 1),
(1987-07-06 05:54:57, 2),
(1982-12-01 02:03:54, 3),
(2008-01-18 22:15:48, 9),
(2006-01-13 23:24:00, 2),
(1983-02-02 19:57:23, 5),
(1976-08-12 20:54:17, 4),
(1988-10-27 00:07:06, 8),
(2006-11-17 18:11:30, 5),
(2006-10-20 02:52:03, 10);

INSERT INTO FoodInfo VALUES
(assumenda, Architecto),
(iste, Totam est ),
(laborum, Maxime et ),
(neque, Est qui eu),
(quidem, Reiciendis),
(quos, Velit eum ),
(recusandae, Ea est fug),
(repudianda, Cumque aut),
(sit, Rem est te),
(sunt, Reiciendis);

INSERT INTO FoodItem VALUES
(assumenda, 1, 5),
(iste, 2, 10),
(laborum, 3, 20),
(neque, 1, 23),
(quidem, 2, 44),
(quos, 3, 51),
(recusandae, 7, 56),
(repudianda, 8, 71),
(sit, 9, 98),
(sunt, 10, 23);

INSERT INTO Contain VALUES 
 (1, 'assumenda', 1),
 (2, 'iste', 2),
 (3, 'laborum', 3),
 (1, 'neque', 1),
 (2, 'quidem', 2),
 (3, 'quos', 4),
 (7, 'recusandae', 5),
 (8, 'repudianda', 2),
 (9, 'sit', 1),
 (10, 'sunt', 1);

我的目标是将与订单编号关联的每个项目的数量和价格的值相乘,然后将它们相加以获得发生的总金额。以下是我尝试的方法:

SELECT Contain.OrderNo
     , Contain.Quantity
     , FoodItem.Price 
  FROM Contain
     , FoodItem 
 WHERE Contain.OrderNo = FoodItem.OrderNo;

+---------+----------+-------+
| OrderNo | Quantity | Price |
+---------+----------+-------+
|       1 |        1 |     5 |
|       1 |        1 |    23 |
|       1 |        1 |     5 |
|       1 |        1 |    23 |
|       2 |        2 |    10 |
|       2 |        2 |    44 |
|       2 |        2 |    10 |
|       2 |        2 |    44 |
|       3 |        3 |    20 |
|       3 |        3 |    51 |
|       3 |        4 |    20 |
|       3 |        4 |    51 |
|       7 |        5 |    56 |
|       8 |        2 |    71 |
|       9 |        1 |    98 |
|      10 |        1 |    23 |
+---------+----------+-------+
16 rows in set (0.00 sec)

使用分组依据:

SELECT FoodItem.OrderNo
     , SUM(FoodItem.Price * Contain.Quantity) AS TOTAL 
  FROM FoodItem 
  JOIN Contain 
    ON FoodItem.OrderNo = Contain.OrderNo 
 GROUP 
    BY Contain.OrderNo;

+---------+-------+
| OrderNo | TOTAL |
+---------+-------+
|       1 |    56 |
|       2 |   216 |
|       3 |   264 |
|       7 |   280 |
|       8 |   142 |
|       9 |    98 |
|      10 |    23 |
+---------+-------+
7 rows in set (0.00 sec)

但是,我想要的输出如下所示:

预期输出:

+---------+-------+
| OrderNo | TOTAL |
+---------+-------+
|       1 |    28 |
|       2 |   108 |
|       3 |   264 |
|       7 |   280 |
|       8 |   142 |
|       9 |    98 |
|      10 |    23 |
+---------+-------+

我找不到正确的SQL语句来生成这个结果。有人能帮我吗?

vdzxcuhz

vdzxcuhz1#

您还需要在JOIN中包含ItemName

SELECT fi.OrderNo, SUM(dfi.Price * c.Quantity) AS TOTAL 
FROM FoodItem fi JOIN
     Contain c
     ON fi.OrderNo = c.OrderNo AND
        fi.ItemName = c.ItemName
GROUP BY c.OrderNo;

匹配不仅仅是在一列上,而是在两列上。你需要两列都匹配,或者不应该匹配的行匹配--结果相乘。

myss37ts

myss37ts2#

向连接中添加另一列ItemName以使其唯一,否则将得到交叉连接
一个一个

  • db〈〉小提琴here*

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