实体框架 - 无法更新EntitySet二进制数据

时间:2011-01-07 14:56:41

标签: c# .net sql entity-framework

实体框架抛出错误:

Test 'WorkerProcessService.Test.WorkerProcessMonitorTests.Test' failed: System.Data.UpdateException : Unable to update the EntitySet 'Processor' because it has a DefiningQuery and no <InsertFunction> element exists in the <ModificationFunctionMapping> element to support the current operation.
 at System.Data.SqlClient.SqlGen.DmlSqlGenerator.ExpressionTranslator.Visit(DbScanExpression expression)
 at System.Data.Common.CommandTrees.DbScanExpression.Accept(DbExpressionVisitor visitor)
 at System.Data.SqlClient.SqlGen.DmlSqlGenerator.GenerateInsertSql(DbInsertCommandTree tree, SqlVersion sqlVersion, List`1& parameters)
 at System.Data.SqlClient.SqlGen.SqlGenerator.GenerateSql(DbCommandTree tree, SqlVersion sqlVersion, List`1& parameters, CommandType& commandType, HashSet`1& paramsToForceNonUnicode)
 at System.Data.SqlClient.SqlProviderServices.CreateCommand(DbProviderManifest providerManifest, DbCommandTree commandTree)
 at System.Data.SqlClient.SqlProviderServices.CreateCommand(DbCommandTree commandTree)
 at System.Data.Mapping.Update.Internal.UpdateTranslator.CreateCommand(DbModificationCommandTree commandTree)
 at System.Data.Mapping.Update.Internal.DynamicUpdateCommand.CreateCommand(UpdateTranslator translator, Dictionary`2 identifierValues)
 at System.Data.Mapping.Update.Internal.DynamicUpdateCommand.Execute(UpdateTranslator translator, EntityConnection connection, Dictionary`2 identifierValues, List`1 generatedValues)
 at System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter)
 at System.Data.EntityClient.EntityAdapter.Update(IEntityStateManager entityCache)
 at System.Data.Objects.ObjectContext.SaveChanges(SaveOptions options)
 at System.Data.Objects.ObjectContext.SaveChanges()
 WorkerProcessMonitor.cs(79,0): at Star.Portal.Services.WorkerProcessMonitor.AddComponent(Byte[] component)
 WorkerProcessMonitorTests.cs(55,0): at WorkerProcessService.Test.WorkerProcessMonitorTests.Test()

我有一个表格,并且自动生成了edmx模型

CREATE TABLE [dbo].[Processor](
  [ProcessorID] [int] IDENTITY(1,1) NOT NULL,
  [ProcessorDLL] [varbinary](max) NULL,
)

以下内容无法更新

public void AddComponent(byte[] component)
        {
            Processor p = new Processor()
                              {
                                  ProcessorDLL = component,
                              };
             using (var cn = GetWorkerProcessEntities())
             {

                 cn.AddToProcessors(p);
                 cn.SaveChanges();
             }

        }

问题是:我是否必须做任何特定的事情来在sql server中实现二进制存储?

1 个答案:

答案 0 :(得分:1)

简单回答...不,我将图像存储在具有相同数据类型(varbinary(max))的表中。

对代码不太了解,我使用本地数据库进行简单测试。 这是我的POCO和DBcontext。 (我不使用自动生成的edmx)

using System.Data.Entity.ModelConfiguration;
public class Processor
{
    public int ProcessorId { get; set; }
    public byte[] ProcessorDLL { get; set; }
}
public class ProcessorConfiguration : EntityTypeConfiguration<Processor>
{
    public ProcessorConfiguration()
    {
        HasKey(i => i.ProcessorId);

        ToTable("Processor", "dbo");
    }
}
//DbContext
public class myContext : DbContext
{
    public DbSet<Processor> Processors { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Configurations.Add(new ProcessorConfiguration());
        base.OnModelCreating(modelBuilder);
    }
}

然后当我添加一个新的处理器时,我使用这个

public void test()
    {
        myContext context = new myContext();

        Processor p = new Processor
        {
            ProcessorDLL = getSomeRandomByteArray()
        };

        context.Processors.Add(p);
        context.SaveChanges();
    }

在我的表格中:

ProcessorID: 1
ProcessorDLL: 0xFFD8FFE000104A46494600010200...

希望这会有所帮助。