无法找出此代码中的错误？

Question

代码：

CREATE TABLE Inventory (
    InventoryNumber INT PRIMARY KEY,
    ProductCode VARCHAR(10),
    ColorCode VARCHAR(10),
    Size VARCHAR(10) NOT NULL,
    Price DECIMAL(10,2) NOT NULL,
    QuantityOnHand INT NOT NULL,
    CONSTRAINT CHK_Inventory_Size CHECK (Size IN ('S', 'M', 'L', 'XL', 'XXL')),
    CONSTRAINT CHK_Inventory_Price CHECK (Price <= 9999.99),
    CONSTRAINT CHK_Inventory_QuantityOnHand CHECK (QuantityOnHand >= 0),
    CONSTRAINT FK_Inventory_Product FOREIGN KEY (ProductCode) REFERENCES Product(ProductCode),
    CONSTRAINT FK_Inventory_Color FOREIGN KEY (ColorCode) REFERENCES Color(ColorCode),
    UNIQUE (ProductCode, ColorCode, Size)
);

Error report -
ORA-00904: : invalid identifier
00904. 00000 -  "%s: invalid identifier"
*Cause:    
*Action:

Answer 1

SIZE

是保留字，不能用作不带引号的标识符。

使用不同的标识符：

CREATE TABLE Inventory (
    InventoryNumber INT PRIMARY KEY,
    ProductCode,
    ColorCode,
    ItemSize        VARCHAR(10) NOT NULL,
    Price           DECIMAL(10,2) NOT NULL,
    QuantityOnHand  INT NOT NULL,
    CONSTRAINT CHK_Inventory_Size CHECK (ItemSize IN ('S', 'M', 'L', 'XL', 'XXL')),
    CONSTRAINT CHK_Inventory_Price CHECK (Price <= 9999.99),
    CONSTRAINT CHK_Inventory_QuantityOnHand CHECK (QuantityOnHand >= 0),
    CONSTRAINT FK_Inventory_Product FOREIGN KEY (ProductCode) REFERENCES Product(ProductCode),
    CONSTRAINT FK_Inventory_Color FOREIGN KEY (ColorCode) REFERENCES Color(ColorCode),
    UNIQUE (ProductCode, ColorCode, ItemSize)
);

或使用带引号的标识符（尽管这不被认为是好的做法，因为您必须在使用列的所有地方都使用带引号的标识符）：

CREATE TABLE Inventory (
    InventoryNumber INT PRIMARY KEY,
    ProductCode,
    ColorCode,
    "Size"          VARCHAR(10) NOT NULL,
    Price           DECIMAL(10,2) NOT NULL,
    QuantityOnHand  INT NOT NULL,
    CONSTRAINT CHK_Inventory_Size CHECK ("Size" IN ('S', 'M', 'L', 'XL', 'XXL')),
    CONSTRAINT CHK_Inventory_Price CHECK (Price <= 9999.99),
    CONSTRAINT CHK_Inventory_QuantityOnHand CHECK (QuantityOnHand >= 0),
    CONSTRAINT FK_Inventory_Product FOREIGN KEY (ProductCode) REFERENCES Product(ProductCode),
    CONSTRAINT FK_Inventory_Color FOREIGN KEY (ColorCode) REFERENCES Color(ColorCode),
    UNIQUE (ProductCode, ColorCode, "Size")
);

小提琴