使用实体框架,我的代码使用LINQ来获取需要从数据库中删除的对象集合。根据具体情况,此集合有时相当大 - 30或40个对象。
我继续尝试从相关对象中取消这些对象,以便我可以删除它们,然后我对每个对象调用context.DeleteObject(),最后是context.SaveChanges()。
大多数情况下,这非常有效,特别是当要删除的对象集合非常小时。但是当它很大时,这个代码有时会引用参考完整性并出现错误,特别是:
The DELETE statement conflicted with the REFERENCE constraint
\"FK_ServiceFeatureSchemaFragmentSchemaFragment_SchemaFragment\".
The conflict occurred in database \"MyDataBase\",
table \"dbo.ServiceFeatureSchemaFragmentSchemaFragment\".\r\n
The statement has been terminated.
所以看起来有时我的对象有额外的约束,我在删除之前无法找到和解耦。
我正在努力的是因为我正在处理一个相对较大的集合,我无法确定哪一个导致这种情况发生。我正在寻找关于如何通过某种方式识别问题对象来推进的建议,例如,有一种方法可以预先确定集合中的对象是否会在您之前抛出这些类型的错误删除它们?还是另一种方法?
感谢收到的建议。
答案 0 :(得分:0)
在SQL Server中编写存储过程,您可以在其中看到FK / PK关系的影响,而无需额外的EF映射层来混淆事物。此示例使用User的主要配置文件表中的基于整数的ezUserID或ASP.NET成员资格GUID来开始删除。
您可以在定义关系时使用级联删除...
SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER ON
GO
CREATE PROC [dbo].[ezUser_Delete]
@ezUserID int = NULL,
@UserName nvarchar(128) = NULL
AS
BEGIN
SET NOCOUNT ON
DECLARE @UserID uniqueidentifier;
--DECLARE @TranName VARCHAR(20); --Generally shouldn't use named transactions in stored procedures
--SELECT @TranName = 'MyTransaction';
SET XACT_ABORT ON
IF @ezUserID IS NULL AND @UserName IS NULL RETURN 0
BEGIN TRY
BEGIN TRANSACTION;
IF ISNULL(@ezUserID, 0) > 0
BEGIN
SELECT @UserID = UserID FROM ezUsers WHERE ezUserID = @ezUserID
SELECT @UserName = UserName FROM aspnet_Users WHERE UserID = @UserID
IF (@UserName IS NULL)
BEGIN
ROLLBACK TRANSACTION;
RETURN -1
END
END
ELSE IF (LEN(ISNULL(@UserName,'')) > 0)
BEGIN
SELECT @UserID = UserID FROM aspnet_Users WHERE UserName = @UserName
SELECT @ezUserID = ezUserID FROM ezUsers WHERE UserID = @UserID
IF (@ezUserID IS NULL)
BEGIN
ROLLBACK TRANSACTION;
RETURN -1
END
END
ELSE
RETURN -1
SELECT 'DELETE' AS [Command]
, U.UserID
, U.UserName
, RoleName
, M.Email
, EU.ezUserID
, EU.FirstName, EU.LastName
, CallSign
, Gender
, UIR.RoleID
FROM dbo.aspnet_Users U
LEFT OUTER JOIN dbo.aspnet_Membership M ON U.UserID = M.UserID
LEFT OUTER JOIN dbo.ezUsers EU ON U.UserID = EU.UserID
LEFT OUTER JOIN dbo.aspnet_UsersInRoles UIR ON U.UserID = UIR.UserID
LEFT OUTER JOIN dbo.aspnet_Roles R ON UIR.RoleID = R.RoleID
WHERE U.UserID = @UserID
IF @UserID IS NULL
RETURN -1
DELETE FROM dbo.ezUsersDating WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezUsersPhysicalIdentity WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezMessages WHERE AuthorID = @ezUserID
DELETE FROM dbo.ezTheUsual WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezRentals WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezUsersSharedActivities WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezCurrentVehicle WHERE UVID IN (SELECT UVID FROM dbo.ezUsersVehicles WHERE ezUserID = @ezUserID)
DELETE FROM dbo.ezDriverVehicles WHERE ezUserID = @ezUserID -- Delete this Table
DELETE FROM dbo.ezOwnerVehicles WHERE OwnerID = @ezUserID
DELETE FROM dbo.ezUsersVehicles WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezPL8Messages
WHERE PL8ID IN (
SELECT PL8ID FROM dbo.ezPL8s WHERE VehicleID IN (SELECT VehicleID FROM dbo.ezVehicles WHERE CreatedBy = @ezUserID))
DELETE FROM dbo.ezPL8s WHERE VehicleID IN (SELECT VehicleID FROM dbo.ezVehicles WHERE CreatedBy = @ezUserID)
DELETE FROM dbo.ezPL8s_Vehicles WHERE VehicleID IN (SELECT VehicleID FROM dbo.ezVehicles WHERE CreatedBy = @ezUserID)
DELETE FROM dbo.ezVehicles WHERE CreatedBy = @ezUserID
DELETE FROM dbo.ezImages_Users
WHERE ImageID IN (SELECT ImageID FROM dbo.ezImages
WHERE UploadedBy = @ezUserID)
DELETE FROM dbo.ezImages_Users
WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezImages
WHERE UploadedBy = @ezUserID
DELETE FROM dbo.ezPets
WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezAccounts
WHERE CPID IN (SELECT CPID FROM dbo.ezCompany_People WHERE ezUserID = @ezUserID)
DELETE FROM dbo.ezCompany_People
WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezMedicals
WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezVehicles WHERE CreatedBy = @ezUserID
DELETE FROM dbo.ezParentChildren WHERE ParentID = @UserID OR ChildID = @UserID
DELETE FROM dbo.ezEmergencyContacts WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezDriveThrus_Customers WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezRelationshipsP2P WHERE RelFromID = @UserID OR RelToID = @UserID
DELETE FROM [dbo].[ezPL8Meaning] WHERE ezUserID = @ezUserID
DELETE FROM dbo.ezUsers WHERE UserID = @UserID
DELETE FROM dbo.aspnet_PersonalizationPerUser WHERE UserID = @UserID
DELETE FROM dbo.aspnet_Profile WHERE UserID = @UserID
DELETE FROM dbo.aspnet_UsersInRoles WHERE UserID = @UserID
DELETE FROM dbo.aspnet_Membership WHERE UserID = @UserID
DELETE FROM dbo.aspnet_Users WHERE UserID = @UserID
COMMIT TRANSACTION;
END TRY
BEGIN CATCH
SELECT ERROR_NUMBER(), ERROR_MESSAGE();
IF @@TRANCOUNT > 0
ROLLBACK TRANSACTION;
RAISERROR('Error', 16, 1)
RETURN 0
END CATCH
END
GO