我正在尝试更新数据库实体 (MamConfiguration_V1) 中的现有实体，称之为父级
我要
1) 给它添加一个引用(导航)成员 (MamConfigurationToBrowser_V1) 称它为 Child
2) 我不更改父实体中唯一属性的值。 (家长姓名)
我从数据库中获取了要更新的实体，
并使用相同的上下文 (mMamDbEntities)
我添加了引用成员。
我不更改它的 Name 属性。
但是我遇到了一个数据库错误，违反了唯一性限制
{"Violation of UNIQUE KEY constraint 'UQ_MamConfigurations_V1'. Cannot insert duplicate key in object 'dbo.MamConfiguration_V1'. The duplicate key value is (elad_14Apr_1315).\r\nThe statement has been terminated."}
我做了数据库嗅探并看到了生成的代码:
exec sp_executesql N'update [dbo].[MamConfiguration_V1]
set [Name] = @0, [Description] = @1, [StatusId] = @2, [Type] = @3, [UpdatedDate] = @4, [PercentageTraffic] = @5, [NumericTraffic] = @6
where ([ConfigurationId] = @7)
',N'@0 nvarchar(50),@1 nvarchar(200),@2 int,@3 int,@4 datetime2(7),@5 int,@6 int,@7 int',@0=N'elad_17Apr_1120_tmpToRemove_',@1=N'elad_22Apr_1120',@2=2,@3=0,@4='2013-04-23 11:17:25.4991650',@5=55,@6=-1,@7=32
//更多命令
exec sp_executesql N'insert [dbo].[MamConfiguration_V1]([Name], [Description], [StatusId], [Type], [CreatedDate], [UpdatedDate], [PercentageTraffic], [NumericTraffic])
values (@0, @1, @2, @3, @4, @5, @6, @7)
select [ConfigurationId]
from [dbo].[MamConfiguration_V1]
where @@ROWCOUNT > 0 and [ConfigurationId] = scope_identity()',N'@0 nvarchar(50),@1 nvarchar(200),@2 int,@3 int,@4 datetime2(7),@5 datetime2(7),@6 int,@7 int',@0=N'elad_17Apr_1120_tmpToRemove_',@1=N'elad_22Apr_1120',@2=2,@3=0,@4='0001-01-01 00:00:00',@5='0001-01-01 00:00:00',@6=55,@7=-1
我原以为 upsert 是 @@ROWCOUNT = 0
我做错了什么？
我的代码和数据库是:
public void SaveCofiguration(MamConfiguration_V1Ui itemUi)
{
var itemEf = mMamConfiguration_V1UiToEfConvertor.ConvertToNewEf(itemUi);
using (var maMDBEntities = new MaMDBEntities())
{
IDal<MamConfiguration_V1> mamConfigurationDal = mDalFactory.GetDal<MamConfiguration_V1>(maMDBEntities);
mamConfigurationDal.Save(itemEf);
}
}
public MamConfiguration_V1 GetById(object id)
{
id.ThrowIfNull("id");
int configurationId = Convert.ToInt32(id);
var result =
mMaMDBEntities.MamConfiguration_V1.SingleOrDefault(item => item.ConfigurationId == configurationId);
return result;
}
public MamConfiguration_V1 Save(MamConfiguration_V1 item)
{
item.ThrowIfNull("item");
var itemFromDB = GetById(item.ConfigurationId);
if (itemFromDB != null)
{
UpdateEfItem(itemFromDB, item);
// if (mMaMDBEntities.ObjectStateManager.GetObjectStateEntry(itemFromDB).State == EntityState.Detached)
// {
// mMaMDBEntities.MamConfiguration_V1.AddObject(itemFromDB);
// }
// Attached object tracks modifications automatically
mMaMDBEntities.SaveChanges();
return item;
}
private void UpdateEfItem(MamConfiguration_V1 itemFromDb, MamConfiguration_V1 itemFromUi)
{
itemFromDb.UpdatedDate = DateTime.Now;
itemFromDb.Description = itemFromUi.Description;
itemFromDb.StatusId = itemFromUi.StatusId;
itemFromDb.Name = itemFromUi.Name;
itemFromDb.NumericTraffic = itemFromUi.NumericTraffic;
itemFromDb.PercentageTraffic = itemFromUi.PercentageTraffic;
itemFromDb.Type = itemFromUi.NumericTraffic;
foreach (var item in itemFromDb.MamConfigurationToBrowser_V1.ToList())
{
if (itemFromUi.MamConfigurationToBrowser_V1.All(b => b.BrowserVersionId != item.BrowserVersionId))
{
mMaMDBEntities.MamConfigurationToBrowser_V1.DeleteObject(item);
}
}
for (int i = 0; i < itemFromUi.MamConfigurationToBrowser_V1.Count; i++)
{
var element = itemFromUi.MamConfigurationToBrowser_V1.ElementAt(i);
var item = itemFromDb.MamConfigurationToBrowser_V1.SingleOrDefault(b => b.BrowserVersionId == element.BrowserVersionId);
if (item != null)
{
// copy properties from element to item
}
else
{
element.Browser = mMaMDBEntities.Browsers.Single(browserItem =>
browserItem.BrowserID == element.BrowserID);
//element.MamConfiguration_V1 = itemFromDb;
//have also tried: element.MamConfiguration_V1 = null;
//element.MamConfiguration_V1Reference = null;
itemFromDb.MamConfigurationToBrowser_V1.Add(element);
}
}
}
更新:
mMaMDBEntities.SaveChanges(); 抛出异常
这些是数据库表:
CREATE TABLE [dbo].[MamConfiguration_V1](
[ConfigurationId] [int] IDENTITY(1,1) NOT NULL,
[Name] [nvarchar](50) NOT NULL,
[Description] [nvarchar](200) NOT NULL,
[StatusId] [int] NOT NULL,
[Type] [int] NOT NULL,
[CreatedDate] [datetime2](7) NOT NULL,
[UpdatedDate] [datetime2](7) NOT NULL,
[PercentageTraffic] [int] NOT NULL,
[NumericTraffic] [int] NOT NULL,
CONSTRAINT [PK_MamConfigurations_V1] PRIMARY KEY CLUSTERED
(
[ConfigurationId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [SECONDARY],
CONSTRAINT [UQ_MamConfigurations_V1] UNIQUE NONCLUSTERED
(
[Name] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [SECONDARY]
) ON [SECONDARY]
GO
ALTER TABLE [dbo].[MamConfiguration_V1] WITH CHECK ADD CONSTRAINT [FK_MamConfiguration_V1_ConfigurationType_V1] FOREIGN KEY([StatusId])
REFERENCES [dbo].[MamConfigurationStatuses] ([StatusId])
GO
ALTER TABLE [dbo].[MamConfiguration_V1] CHECK CONSTRAINT [FK_MamConfiguration_V1_ConfigurationType_V1]
GO
ALTER TABLE [dbo].[MamConfiguration_V1] ADD CONSTRAINT [DF_MamConfigurations_V1_CreatedDate] DEFAULT (getdate()) FOR [CreatedDate]
GO
ALTER TABLE [dbo].[MamConfiguration_V1] ADD CONSTRAINT [DF_MamConfigurations_V1_UpdatedDate] DEFAULT (getdate()) FOR [UpdatedDate]
GO
CREATE TABLE [dbo].[MamConfigurationToBrowser_V1](
[MamConfigurationId] [int] NOT NULL,
[BrowserVersionId] [uniqueidentifier] NOT NULL,
[IsWhiteListed] [bit] NOT NULL,
[BrowserID] [int] NOT NULL,
[VersionNumberLowRange] [varchar](50) NOT NULL,
[CreatedDate] [datetime] NOT NULL,
[UpdatedDate] [datetime] NOT NULL,
[VersionNumberUpperRange] [varchar](50) NULL,
CONSTRAINT [PK_MamConfigurationToBrowser_V1_1] PRIMARY KEY CLUSTERED
(
[BrowserVersionId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [SECONDARY]
) ON [SECONDARY]
GO
SET ANSI_PADDING OFF
GO
ALTER TABLE [dbo].[MamConfigurationToBrowser_V1] WITH CHECK ADD CONSTRAINT [FK_MamConfigurationToBrowser_V1_Browsers] FOREIGN KEY([BrowserID])
REFERENCES [dbo].[Browsers] ([BrowserID])
GO
ALTER TABLE [dbo].[MamConfigurationToBrowser_V1] CHECK CONSTRAINT [FK_MamConfigurationToBrowser_V1_Browsers]
GO
ALTER TABLE [dbo].[MamConfigurationToBrowser_V1] WITH CHECK ADD CONSTRAINT [FK_MamConfigurationToBrowser_V1_BrowserVersion] FOREIGN KEY([MamConfigurationId])
REFERENCES [dbo].[MamConfiguration_V1] ([ConfigurationId])
GO
ALTER TABLE [dbo].[MamConfigurationToBrowser_V1] CHECK CONSTRAINT [FK_MamConfigurationToBrowser_V1_BrowserVersion]
GO
ALTER TABLE [dbo].[MamConfigurationToBrowser_V1] ADD CONSTRAINT [DF_Browser_V1_CreatedDate] DEFAULT (getdate()) FOR [CreatedDate]
GO
ALTER TABLE [dbo].[MamConfigurationToBrowser_V1] ADD CONSTRAINT [DF_Browser_V1_UpdatedDate] DEFAULT (getdate()) FOR [UpdatedDate]
GO
更新 2
我试过@AzharKhorasany 的解决方案，但出现了同样的错误:
for (int i = 0; i < itemFromUi.MamConfigurationToBrowser_V1.Count; i++)
{
var element = itemFromUi.MamConfigurationToBrowser_V1.ElementAt(i);
var item = itemFromDb.MamConfigurationToBrowser_V1.SingleOrDefault(b => b.BrowserVersionId == element.BrowserVersionId);
if (item != null)
{
// copy properties from element to item
}
else
{
element.Browser = mMaMDBEntities.Browsers.Single(browserItem =>
browserItem.BrowserID == element.BrowserID);
element.MamConfigurationId = itemFromDb.ConfigurationId;
//element.MamConfiguration_V1 = itemFromDb;
//have also tried: element.MamConfiguration_V1 = null;
//element.MamConfiguration_V1Reference = null;
//mMaMDBEntities.AddToMamConfigurationToBrowser_V1(itemFromUi.MamConfigurationToBrowser_V1.ElementAt(0)); // add as inserted
itemFromDb.MamConfigurationToBrowser_V1.Add(element);
}
}
最佳答案
您的代码非常冗长，其中很多与实际保存操作无关，但我想我明白您在做什么。首先，根据错误，您确实定义了新项目的 ID，它代表数据库中的某些内容，我想这就是您所期望的。
当您使用 Add() 时，您是在告诉 EF 您有新的东西，而它告诉您它已经有了。您反而/另外需要将实体状态从“已添加”更改为“未更改”。在 EF 中，您可以使用以下语法执行此操作:
DbContext.Entry(entity).State = EntityState.Unchanged;
还有其他方法可以做到这一点，所以请稍微研究一下。此外，EF 有一些辅助代码可以自动将值从一个实例复制到另一个实例。您需要搜索细节，但一般语法是:
DbContext.Entry(entityforUpdate).CurrentValues.SetValues(updatedDetachedEntity)
祝你好运!
关于c# - EF 使用新引用更新现有实体并获取违反唯一键约束，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16133182/