SQL循環或多級聯路徑

Question

我遇到週期問題。我正在爲IT部門開發庫存系統。 我有3個表的問題。

INVENTORY表用於保留用戶操作的歷史記錄，SOFTWARE和HARDWARE表用於存儲庫存。

我想保持一個inventoryID這是SOFTWARE和HARDWARE表獨特的，當我使用ON CASCADE DELETE我得到一個錯誤：

Msg 1785, Level 16, State 0, Line 1
Introducing FOREIGN KEY constraint 'fk_inventory_inventoryIDhw' on table 'inventory' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.

這裏是我的表。任何人都可以幫我嗎？如何解決這個問題。無法在網絡上找到正確的解決方案。謝謝

CREATE TABLE inventory 
( 
    statusID int, 
    inventoryStatus nvarchar(15), 
    inventoryID int, 
    userName nvarchar(15), 
    dates datetime2, 
    inventoryAction nvarchar(10), 
    categoryID int, 

    CONSTRAINT pk_inventory_statusID PRIMARY KEY(statusID), 
    CONSTRAINT fk_inventory_inventoryIDsw FOREIGN KEY(inventoryID) REFERENCES  software(inventoryID) ON DELETE CASCADE, 
    CONSTRAINT fk_inventory_inventoryIDhw FOREIGN KEY(inventoryID) REFERENCES hardware(inventoryID) ON DELETE CASCADE, 
    CONSTRAINT fk_inventory_userName FOREIGN KEY(userName) REFERENCES users(userName) ON DELETE CASCADE 
) 
GO 

CREATE TABLE hardware 
(
    inventoryID int, 
    hardwareID int, 
    partNumber nvarchar(15), 
    serial nvarchar(50), 
    price float, 
    supportID int, 
    manufacturerID int, 
    categoryID int, 
    description nvarchar, 
    deviceTypeID int, 

    CONSTRAINT pk_hardware_inventoryID PRIMARY KEY(inventoryID), 
    CONSTRAINT fk_hardware_categoryID FOREIGN KEY(categoryID) REFERENCES category(categoryID) ON DELETE CASCADE, 
    CONSTRAINT fk_hardware_supportID FOREIGN KEY(supportID) REFERENCES support(supportID) ON DELETE CASCADE, 
    CONSTRAINT fk_hardware_deviceTypeID FOREIGN KEY(deviceTypeID) REFERENCES deviceType(deviceTypeID) ON DELETE CASCADE, 
    CONSTRAINT fk_hardware_manufacturerID FOREIGN KEY(manufacturerID) REFERENCES manufacturer(manufacturerID) ON DELETE CASCADE, 
) 
GO 

CREATE TABLE software 
(
    inventoryID int, 
    softwareID int, 
    version nvarchar(10), 
    name nvarchar(50), 
    license nvarchar(50), 
    price float, 
    supportID int, 
    categoryID int, 
    manufacturerID int, 
    programTypeID int, 
    description nvarchar, 

    CONSTRAINT pk_software_inventoryID PRIMARY KEY(inventoryID), 
    CONSTRAINT fk_software_categoryID FOREIGN KEY(categoryID) REFERENCES category(categoryID) ON DELETE CASCADE, 
    CONSTRAINT fk_software_supportID FOREIGN KEY(supportID) REFERENCES support(supportID) ON DELETE CASCADE, 
    CONSTRAINT fk_software_programTypeID FOREIGN KEY(programTypeID) REFERENCES  programType(programTypeID) ON DELETE CASCADE, 
    CONSTRAINT fk_software_manufacturerID FOREIGN KEY(manufacturerID) REFERENCES  manufacturer(manufacturerID) ON DELETE CASCADE 
) 
GO 

Answer 1

據我記得，對多個父表關聯的同一列上的多個fk約束是不可行的。您可能需要另一個表來維護這種關係。請參閱：http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=173589