Question

在sql server 2012中，我有表PurchaseReturn(VendorId,PurchaseOrderId)。 “Vendorid”列是与Vendor（VendorId）的外键关系，“Purchaseorderid”是Purchaseorder（purchaseorderi）。现在我的目标是将'VendorId'的外键类型设置为'On delete在Update Cascade上设置Null'，但对于'purchaseorderid'，它应该是'On delete CasCade On Update Cascade'。

但是当我为VendorId创建FK并尝试通过以下查询为PurchaseOrderId创建它时：

alter table PurchaseReturn add constraint FK_PR_PORD foreign key (Purchaseorderid) references PurchaseOrder(Purchaseorderid) on delete cascade ON UPDATE CASCADE ';

错误如下所示：在表'PurchaseReturn'上引入FOREIGN KEY约束'FK_PR_PORD'可能会导致循环或多个级联路径。指定ON DELETE NO ACTION或ON UPDATE NO ACTION，或修改其他FOREIGN KEY约束。

有什么问题？...请提前帮助谢谢这是具有约束

的创建表查询alonq

USE [AsifTraders]
GO

/****** Object:  Table [dbo].[PurchaseReturn]    Script Date: 24-Sep-14 11:46:39 AM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[PurchaseReturn](
    [Date] [datetime] NOT NULL,
    [PurchaseReturnId] [nvarchar](20) NOT NULL,
    [VendorId] [nvarchar](8) NULL,
    [Description] [nvarchar](50) NOT NULL,
    [ReturnType] [nvarchar](20) NOT NULL,
    [Deduction] [numeric](15, 0) NULL,
    [ProductQuantity] [numeric](10, 2) NOT NULL,
    [PurchaseValue] [numeric](12, 0) NOT NULL,
    [ReturnValue] [numeric](15, 0) NOT NULL,
    [Paid] [numeric](15, 0) NULL,
    [PBalance] [numeric](15, 0) NULL,
    [NBalance] [numeric](15, 0) NULL,
    [JEntryId] [int] NOT NULL,
    [PURCHASEORDERID] [nvarchar](8) NULL,
 CONSTRAINT [PK_PurchaseReturn] PRIMARY KEY CLUSTERED 
(
    [PurchaseReturnId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

ALTER TABLE [dbo].[PurchaseReturn]  WITH CHECK ADD  CONSTRAINT [FK_PR_VEN] FOREIGN KEY([PURCHASEORDERID])
REFERENCES [dbo].[PurchaseOrder] ([PurchaseOrderId])
ON UPDATE CASCADE
ON DELETE CASCADE
GO

ALTER TABLE [dbo].[PurchaseReturn] CHECK CONSTRAINT [FK_PR_VEN]
GO

这是PurhcaseOrder的查询

USE [AsifTraders]
GO

/****** Object:  Table [dbo].[PurchaseOrder]    Script Date: 24-Sep-14 11:56:53 AM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[PurchaseOrder](
    [Date] [datetime] NULL,
    [PurchaseOrderId] [nvarchar](8) NOT NULL,
    [JEntryId] [int] NULL,
    [VendorId] [nvarchar](8) NULL,
    [PurchaseType] [nvarchar](10) NULL,
    [Description] [nvarchar](50) NOT NULL,
    [ItemQuantity] [numeric](18, 0) NOT NULL,
    [DeleiveryCharges] [numeric](18, 0) NULL,
    [Discount] [numeric](18, 0) NULL,
    [Total] [numeric](18, 0) NOT NULL,
    [Paid] [numeric](18, 0) NULL,
    [PBalance] [numeric](18, 0) NULL,
    [NBalance] [numeric](18, 0) NULL,
PRIMARY KEY CLUSTERED 
(
    [PurchaseOrderId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

ALTER TABLE [dbo].[PurchaseOrder]  WITH CHECK ADD  CONSTRAINT [fk_purch_ven] FOREIGN KEY([VendorId])
REFERENCES [dbo].[Vendor] ([VendorId])
ON UPDATE CASCADE
ON DELETE CASCADE
GO

ALTER TABLE [dbo].[PurchaseOrder] CHECK CONSTRAINT [fk_purch_ven]
GO

更新级联上删除级联的外键关系

0 个答案: