Sql server 由于连接，LINQ到SQL插入失败

我的数据库中有两个表

Users

和

HealthMonitor

。在

HealthMonitor

表中，我有一个

UserID

字段，该字段映射到

Users

表中的

ID

字段

到目前为止相当直接

我将

HealthMonitor

表中的

UserID

字段保留为“Nullable”，这样，如果当前没有用户登录，我就可以让系统在表中插入NULL值。。。IE：如果错误被抛出到未经身份验证的用户

问题是，当我试图在

UserID

字段中插入NULL时，插入失败

仅供参考：消除关系也会消除问题，但我知道这可能不是完成任务的最佳方式

编辑： 在重新应用关系并确保

UserID

可为空后，它现在似乎可以工作了。。。但是，插入的值为

0

not

null

    Public Sub AddException(ByVal ex As Exception, Optional ByVal notes As String = Nothing) Implements IHealthMonitorService.AddException
        Dim exception As HealthMonitor = New HealthMonitor
        Dim userID As Integer = Nothing
        If HttpContext.Current.User.Identity.IsAuthenticated Then userID = Authentication.CustomAuthentication.RetrieveAuthUser.ID

        Dim DataConverter As Utilities.DataConverters = New Utilities.DataConverters
        Dim InformationHelper As Utilities.InformationHelper = New Utilities.InformationHelper

        With exception
            .DateTime = DateTime.Now
            .Exception = ex.ToString
            .Message = ex.Message
            .Notes = notes
            .ShortMessage = If(ex.Message.Length > 50, ex.Message.Substring(0, 50), ex.Message)
            .Source = ex.Source
            .StackTrace = ex.StackTrace
            .Url = HttpContext.Current.Request.Url.ToString()
            .UserID = userID
            .UserIP = DataConverter.IPAddressToNumber(InformationHelper.GetUserIP)
            .UserOS = InformationHelper.GetUserOS()
            .UserBrowser = InformationHelper.GetUserBrowser()
        End With

        _HealthMonitorRepository.AddException(exception)
    End Sub

我是不是遗漏了什么？是否可以将其插入为

NULL

编辑： 好吧，我撒了一点谎。我仍然得到错误

    Public Sub AddException(ByVal exception As HealthMonitor) Implements IHealthMonitorRepository.AddException
        dc.HealthMonitors.InsertOnSubmit(exception)
        dc.SubmitChanges()  ''# ERROR HERE
    End Sub

INSERT语句与外键约束“FK_un_HealthMonitor_un_Users”冲突。冲突发生在数据库“UrbanNow”、表“dbo.un_Users”、列“ID”中。 声明已终止

这是桌子

/****** Object:  Table [dbo].[un_HealthMonitor]    Script Date: 07/24/2010 10:48:39 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[un_HealthMonitor](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [UserID] [int] NULL,
    [Exception] [nvarchar](4000) NULL,
    [Url] [nvarchar](2048) NULL,
    [Source] [nvarchar](4000) NULL,
    [ShortMessage] [nvarchar](50) NULL,
    [Message] [nvarchar](4000) NULL,
    [StackTrace] [nvarchar](4000) NULL,
    [UserIP] [nvarchar](50) NULL,
    [UserBrowser] [nvarchar](50) NULL,
    [UserOS] [nvarchar](50) NULL,
    [UserIsMoblie] [bit] NULL,
    [DateTime] [datetime2](0) NULL,
    [Notes] [nvarchar](4000) NULL,
 CONSTRAINT [PK_un_HealthMonitor] PRIMARY KEY CLUSTERED 
(
    [ID] 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].[un_HealthMonitor]  WITH CHECK ADD  CONSTRAINT [FK_un_HealthMonitor_un_Users] FOREIGN KEY([UserID])
REFERENCES [dbo].[un_Users] ([ID])
GO

ALTER TABLE [dbo].[un_HealthMonitor] CHECK CONSTRAINT [FK_un_HealthMonitor_un_Users]
GO

搞定了

所以基本上在我的服务层我有

    Public Sub AddException(ByVal ex As Exception, Optional ByVal notes As String = Nothing) Implements IHealthMonitorService.AddException
        Dim exception As HealthMonitor = New HealthMonitor
        Dim userID As Integer = Nothing
        If HttpContext.Current.User.Identity.IsAuthenticated Then userID = Authentication.CustomAuthentication.RetrieveAuthUser.ID

        Dim DataConverter As Utilities.DataConverters = New Utilities.DataConverters
        Dim InformationHelper As Utilities.InformationHelper = New Utilities.InformationHelper

        With exception
            .DateTime = DateTime.Now
            .Exception = ex.ToString
            .Message = ex.Message
            .Notes = notes
            .ShortMessage = If(ex.Message.Length > 50, ex.Message.Substring(0, 50), ex.Message)
            .Source = ex.Source
            .StackTrace = ex.StackTrace
            .Url = HttpContext.Current.Request.Url.ToString()
            .UserID = userID
            .UserIP = DataConverter.IPAddressToNumber(InformationHelper.GetUserIP)
            .UserOS = InformationHelper.GetUserOS()
            .UserBrowser = InformationHelper.GetUserBrowser()
        End With

        _HealthMonitorRepository.AddException(exception)
    End Sub

问题是，当我将

userID

发送到异常对象时，它将

0

（零）发送到数据库。这是解决办法

        Dim userID As Integer? = Nothing ''# (?) makes the integer nullable.

---

为了确保您有一个用户，因此不会违反外键，您可以执行以下操作：

`Public Sub AddException(ByVal exception As HealthMonitor) Implements IHealthMonitorRepository.AddException
    ' take what you need from exception to Create a User
    User user = new User{Populate properties here}
    dc.Users.InsertOnSubmit(user)   
    dc.HealthMonitors.InsertOnSubmit(exception)
    dc.SubmitChanges()  ''# ERROR HERE
End Sub'

这样你就可以在需要的时候创建用户

---

或者您可以为用户执行存在性检查。

与其让字段为空，不如用一个触发器来填充一个已知值（“N/a”或“0”或类似值）。触发器-真恶心。如果是这种情况，我可以通过LINQ提交一个“0”值，但仍然失败，因为用户中没有相关的“0”记录table@JNK，当关系的另一端没有任何内容时，Null是正确的值。采取这样的变通办法将是一种耻辱@RockingTheSixstring，您使用的是VS吗？是否已在.dbml设计器中签入该属性标记为Nullable？可能是导入不正确。我没有在设计器中进行检查。我马上去看看。好像当我重建它并检查以确保UserID可以为空时，它现在可以工作了。我编辑了我的问题，因为值是“0”而不是“NULL”，我不想为网站的匿名访问者创建用户，这太可笑了。我找到了答案，看一看。