vb.net – InsertOnSubmit =无法添加具有已在使用的密钥的实体

我试图使用 Linq将记录插入到表中,但是获得可怕的无法添加一个已经在使用的密钥的实体错误

'If the same data exists for the same patient in a record less that 21 days old then drop it
Dim RecordLookup As Integer = 0
RecordLookup = (From rc In CDEvodb.RISKCHANGEs _
    Where rc.NHI = tmpNHI And _
    rc.RECDATE > Date.Now.AddDays(-21) And _
    rc.BPSYS = Convert.ToDecimal(Drow.Item("BPSYS")) And _
    rc.CHOL = Convert.ToDecimal(Drow.Item("CHOL")) And _
    rc.HDL = Convert.ToDecimal(Drow.Item("HDL"))).Count()
If (RecordLookup = 0) Then
Dim riskchange As New RISKCHANGE
    riskchange.NHI = Drow.Item("NHI")
    riskchange.RECDATE = Date.Now.Date()
    riskchange.RISK = CalculatedRisk
    riskchange.BPSYS = Drow.Item("BPSYS")
    riskchange.CHOL = Drow.Item("CHOL")
    riskchange.HDL = Drow.Item("HDL")

    Try
        CDEvodb.RISKCHANGEs.InsertOnSubmit(riskchange)
    Catch ex As Exception
        myLogging.OutputError("<" & DateTime.Now.ToString & "> " & "Error - creating risk change record in dataset for patient " & Drow.Item("NHI").ToString() & " - " & ex.Message)
    End Try

End If

基本上我在表上查找不到21天的匹配记录(不包括Identity字段).如果我找不到一个,我创建一个行的实例并设置插入它.

SubmitChanges函数调用几行.

Drow是来自之前使用SQLClient连接填充的数据集的DataRow(原因是我尚未完全转换为Linq,现在只是执行新功能).

提前干杯.

这是表的创建脚本：

USE [CDEvolution]

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/ ******对象：表[dbo].[RISKCHANGES]脚本日期：05/13/2009 14:40:15 ****** /

SET ANSI_NULLS ON

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SET QUOTED_IDENTIFIER ON

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SET ANSI_PADDING ON

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CREATE TABLE [dbo].[RISKCHANGES](

[NHI] [varchar](7) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,[RECDATE] [datetime] NOT NULL,[RISK] [numeric](15,0) NOT NULL,[BPSYS] [numeric](15,[CHOL] [numeric](15,1) NOT NULL,[HDL] [numeric](15,[POSTED] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,[IDENTITY] [uniqueidentifier] NOT NULL CONSTRAINT [DF_RISKCHANGES_IDENTITY]

DEFAULT(newid()),

CONSTRAINT [PK_RISKCHANGES] PRIMARY KEY CLUSTERED

(

[IDENTITY] ASC

)WITH(PAD_INDEX = OFF,IGNORE_DUP_KEY = OFF)ON [PRIMARY]

)[主要]

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SET ANSI_PADDING OFF

解决方法

如果更新DBML,请将此(IsDbGenerated =“true”)添加到PK成员：

<Column Name="[IDENTITY]" Member="IDENTITY" Type="System.Guid" 
            DbType="UniqueIdentifier NOT NULL" IsPrimaryKey="true" 
            CanBeNull="false" IsDbGenerated="true"/>

它将让SQL分配默认值(newid()).

否则它会发送未经过授权的guid(‘00000000-0000-0000-0000-000000000000’),这就是我所知道的问题.

您的另一个选择可能是扩展部分类并初始化OnCreated()事件中的GUID(它不使用列的newid()默认值,但确实解决了问题：

partial class RISKCHANGE
    {
        partial void OnCreated()
        {
            _IDENTITY = Guid.NewGuid();
        }
    }

请注意,对于现有实体(由查询填充),当处理OnLoaded()时,将使用正确的值覆盖此值.