时间戳

首页 > 解决方案 > 不明确的列名“ProductNumber”

sql - 不明确的列名“ProductNumber”

问题描述

无法弄清楚为什么我的问题 3 会出现上述错误。

下面是我的代码

/* Question 1 */
CREATE TABLE CUSTOMERS 
( 
    CustomerID INT PRIMARY KEY, 
    CustFirstName VARCHAR(50) NOT NULL, 
    CustLastName VARCHAR(50) NOT NULL, 
    CustStreetAddress VARCHAR(50) NOT NULL, 
    CustCity VARCHAR(50) NOT NULL, 
    CustState VARCHAR(26) NOT NULL, 
    CustZipCode INT NOT NULL, 
    CustAreaCode INT NOT NULL, 
    CustPhoneNumber VARCHAR (26) NOT NULL
);  

CREATE TABLE EMPLOYEES 
( 
    EmployeeID INT PRIMARY KEY, 
    EmpFirstName VARCHAR(50) NOT NULL, 
    EmpLastName VARCHAR(50) NOT NULL, 
    EmpCity VARCHAR (50) NOT NULL, 
    EmpState VARCHAR(26) NOT NULL, 
    EmpZipCode INT NOT NULL, 
    EmpAreaCode INT NOT NULL, 
    EmpPhoneNumber VARCHAR(26) NOT NULL, 
    EmpBirthDate DATE NOT NULL
); 

CREATE TABLE ORDERS
( 
    OrderNumber INT PRIMARY KEY, 
    OrderDate DATE NOT NULL, 
    ShipDate DATE NOT NULL, 
    CustomerID INT NOT NULL, 
    EmployeeID INT NOT NULL, 

    FOREIGN KEY(EmployeeID) REFERENCES EMPLOYEES(EmployeeID), 
    FOREIGN KEY(CustomerID) REFERENCES CUSTOMERS(CustomerID)
); 

CREATE TABLE CATEGORIES
( 
    CategoryID INT PRIMARY KEY, 
    CategoryDescription VARCHAR(255) NOT NULL
); 

CREATE TABLE PRODUCTS
(
    ProductNumber INT PRIMARY KEY, 
    ProductName VARCHAR(50) NOT NULL, 
    ProductDescription VARCHAR(255) NOT NULL,
    RetailPrice INT NOT NULL, 
    QuantityOnHand INT NOT NULL, 
    CategoryID INT NOT NULL, 

    FOREIGN KEY(CategoryID) REFERENCES CATEGORIES (CategoryID)
);    

CREATE TABLE ORDER_DETAILS
( 
    OrderNumber INT NOT NULL, 
    ProductNumber INT NOT NULL, 
    QuotedPrice INT NOT NULL, 
    QuantityOrdered INT NOT NULL, 

    PRIMARY KEY (OrderNumber, ProductNumber), 
    FOREIGN KEY (OrderNumber) REFERENCES ORDERS(OrderNumber), 
    FOREIGN KEY(ProductNumber) REFERENCES PRODUCTS(ProductNumber)
);   

CREATE TABLE VENDORS
(
    VendorID INT PRIMARY KEY, 
    VendName VARCHAR(100) NOT NULL, 
    VendStreetAddress VARCHAR(50) NOT NULL, 
    VendCity VARCHAR(50) NOT NULL, 
    VendState VARCHAR(26) NOT NULL, 
    VendFaxNumber VARCHAR(50) NOT NULL, 
    VendWebPage VARCHAR(100) NOT NULL, 
    VendEmailAddress VARCHAR(100) NOT NULL
); 

CREATE TABLE PRODUCT_VENDORS
(
    ProductNumber INT NOT NULL, 
    VendorID INT NOT NULL, 
    WholeSalePrice INT NOT NULL,
    DaysToDeliver INT NOT NULL, 

    PRIMARY KEY(ProductNumber, VendorID), 
    FOREIGN KEY(ProductNumber) REFERENCES PRODUCTS(ProductNumber), 
    FOREIGN KEY(VendorID) REFERENCES Vendors(VendorID)
); 

/* QUESTION 2 */

SELECT 
    OrderDate, CustFirstName, CustLastName
FROM 
    CUSTOMERS C, ORDERS O
WHERE 
    C.CustomerID = O.OrderNumber; 

/* QUESTION 3 */

SELECT 
    ProductNumber, WholeSalePrice, VendName 
FROM 
    PRODUCTS P, PRODUCT_VENDORS PV, VENDORS V 
WHERE 
    P.PRODUCTNUMBER = PV.ProductNumber AND PV.VendorID = V.VendorID;

我得到了错误

不明确的列名“ProductNumber”

标签： sqlsql-server

解决方案

因为在您的查询中有两个表的列名，所以ProductNumber您需要告诉数据库引擎您想要获取哪一列。

另外，使用JOIN而不是,逗号CROSS JOIN，因为Join比逗号更清楚两个表之间的关系

SELECT PV.ProductNumber, WholeSalePrice, VendName 
FROM PRODUCTS P 
JOIN PRODUCT_VENDORS PV ON P.PRODUCTNUMBER = PV.ProductNumber
JOIN VENDORS V ON PV.VendorID = V.VendorID;

推荐阅读