WCF OData 服务和 EF 6 问题 - 无法使用 Odata 服务公开实体

Question

我使用的是带有.NET框架4.5.1和EF 6.1的WCF数据服务（Odata）。我使用了代码优先的方法来创建EF模型。当我将此EF模型（AddProjectModel.cs）引用到WCF OData服务（WcfDataService1.svc）时，它会引发以下错误：

错误：

服务器在处理请求时遇到错误。异常消息为"在数据上下文类型"AddProjectModel"上，存在元素类型不是实体类型的顶级IQueryable属性"Assets"。"。请确保IQueryable属性为实体类型，或者在数据上下文类型上指定IgnoreProperties属性以忽略此属性。'。有关详细信息，请参阅服务器日志。异常堆栈跟踪为：

System.Data.Services.Provider.ReflectionServiceProvider.PopulateMetadata（ProviderMetadataCacheItem metadataCacheItem），位于System.Data.Service.DataService 1.CreateInternalProvider(Object dataSourceInstance) at System.Data.Services.DataService 1.CreateMetadataAndQueryProviders（IDataServiceMetadataProvider和metadataProviderInstance，IDataServiceQueryProvider和queryProviderInstance，Object和dataSourceInstance，Boolean和isInternalCreatedProvider）位于System.Data.Services.DataService 1.CreateProvider() at System.Data.Services.DataService 1.HandleRequest（）位于System.Data_Services.DataService`1.ProcessRequestForMessage（Stream messageBody）位于SyncInvokeProcessRequestForMessage（Object，Object[]，Object[]）System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage41System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage2处System.ServiceModel.Dispatcher.immutableDispatchRunime.ProcessMessage4处的（MessageRpc&rpc）System.ServiceModel.Dispatcher.MessageRpc.Process（布尔isOperationContextSet）上System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage11（MessageRpc&rpc）

这是我的WCF数据服务：WcfDataService1.svc

namespace AddProjectService
{
 public class WcfDataService1 : DataService<AddProjectModel>
 {
    // This method is called only once to initialize service-wide policies.
    public static void InitializeService(DataServiceConfiguration config)
    {
        // TODO: set rules to indicate which entity sets and service operations are visible,
         updatable, etc.
        // Examples:
        config.SetEntitySetAccessRule("*", EntitySetRights.AllRead);
        config.SetServiceOperationAccessRule("*", ServiceOperationRights.All);
        config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V3;
    }
 }
}

我的代码优先模型：AddProjectModel.cs

 public partial class AddProjectModel : DbContext
 {
  public AddProjectModel()
    : base("name=AddProjectModel")
  {
  }
  public virtual DbSet<Asset> Assets { get; set; }
  public virtual DbSet<Project> Projects { get; set; }
  protected override void OnModelCreating(DbModelBuilder modelBuilder)
  {
    modelBuilder.Configurations.Add(new AssetMap());
    modelBuilder.Configurations.Add(new ProjectMap());   
  }         
 }  
 public class AssetMap : EntityTypeConfiguration<Asset>
 {
  public AssetMap()
  {
  this.Property(a => a.AssetId).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);      
  this.HasMany(a => a.Projects).WithRequired(p => p.Asset).HasForeignKey(p => p.AssetId);
  //table  & column mappings
  this.ToTable("TBLASSET");
  this.Property(a => a.AssetId).HasColumnName("ASSETID");
  this.Property(a => a.AssetLevelId).HasColumnName("ASSETLEVELID");
  this.Property(a => a.AssetNumber).HasColumnName("ASSETNUMBER");
  this.Property(a => a.Name).HasColumnName("NAME");
  this.Property(a => a.AssetTypeId).HasColumnName("ASSETTYPEID");      
 }
}  
public class ProjectMap : EntityTypeConfiguration<Project>
{
  public ProjectMap()
  {
   this.Property(p => p.ProjectId).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
   this.HasMany(p => p.SchedulePhases).WithRequired(sp => sp.Project).HasForeignKey(sp => 
   sp.ProjectId); 
  //table & column mappings
  this.ToTable("TBLPROJECT");
  this.Property(p => p.ProjectId).HasColumnName("PROJECTID");
  this.Property(p => p.AssetId).HasColumnName("ASSETID");
  this.Property(p => p.CapitalCategoryId).HasColumnName("CAPITALCATEGORYID");
  this.Property(p => p.Comments).HasColumnName("COMMENTS");
  this.Property(p => p.DesignationId).HasColumnName("DESIGNATIONID");
  this.Property(p => p.DispositionId).HasColumnName("DISPOSITIONID");
  this.Property(p => p.FMSNumber).HasColumnName("FMSNUMBER");
  this.Property(p => p.FundingSourceId).HasColumnName("FUNDINGSOURCEID");
  this.Property(p => p.ImplementerId).HasColumnName("IMPLEMENTERID");
  this.Property(p => p.IsApproved).HasColumnName("ISAPPROVED");
  this.Property(p => p.IsDeferred).HasColumnName("ISDEFERRED");
  this.Property(p => p.IsLongTermLease).HasColumnName("ISLONGTERMLEASE");
  this.Property(p => p.IsRollover).HasColumnName("ISROLLOVER");
  this.Property(p => p.IsSidewalkBridge).HasColumnName("ISSIDEWALKBRIDGE");
  this.Property(p => p.JobDescription).HasColumnName("JOBDESCRIPTION");
  this.Property(p => p.JobType).HasColumnName("JOBTYPE");
  this.Property(p => p.OrganizationId).HasColumnName("ORGANIZATIONID");
  this.Property(p => p.ProgramCategoryId).HasColumnName("PROGRAMCATEGORYID");
  this.Property(p => p.DsfId).HasColumnName("DSFID");
  this.Property(p => p.StatusId).HasColumnName("STATUSID");
  this.Map<DomainObjectModel.ObjectModel.Project.ProjectCIP>(m => m.Requires("PROJECTTYPEID").HasValue(15))
      .Map<DomainObjectModel.ObjectModel.Project.ProjectCapacity>(m => m.Requires("PROJECTTYPEID").HasValue(2));
 }
}

资产类别：

public class Asset
{
 public Asset()
 {
   Projects = new HashSet<Project>();      
 }
 [Key]
 public decimal AssetId { get; set; }
 [StringLength(20)]
 public string AssetNumber { get; set; }
 [StringLength(100)]
 public string Name { get; set; }
 public decimal? AssetLevelId { get; set; }
 public decimal? AssetTypeId { get; set; }
 public virtual ICollection<Project> Projects { get; set; }    
}

项目类别：

public class Project
{
 public Project()
 {      
 } 
 [Key]
 public decimal ProjectId { get; set; }
 public decimal AssetId { get; set; }
 public decimal CapitalCategoryId { get; set; }
 //public decimal ProjectTypeId { get; set; }
 public decimal ProgramCategoryId { get; set; }   
 [StringLength(1024)]
 public string Comments { get; set; }
 public decimal ImplementerId { get; set; }
 public decimal StatusId { get; set; }
 public decimal DsfId { get; set; }
 [StringLength(20)]
 public string FMSNumber { get; set; }
 [StringLength(1024)]
 public string JobDescription { get; set; }
 [StringLength(2)]
 public string JobType { get; set; }
 public decimal OrganizationId { get; set; }
 [Required][StringLength(1)]
 public string IsRollover { get; set; }
 [Required][StringLength(1)]
 public string IsDeferred { get; set; }
 [Required][StringLength(1)]
 public string IsApproved { get; set; }
 [StringLength(1)]
 public string IsSidewalkBridge { get; set; }
 public decimal FundingSourceId { get; set; }
 public decimal? DesignationId { get; set; }
 public decimal? DispositionId { get; set; }
 [Required][StringLength(1)]
 public string IsLongTermLease { get; set; }
 public virtual Asset Asset { get; set; }   
}

我不知道如何解决这个问题。你能告诉我我这里缺了什么吗？

我正在使用oracle数据库，最近我们从devart购买了用于oracle的dotConnect的许可证。

谢谢，

---

你好，

我通过在每个POCO类上设置带有主键的[DataServiceKey]属性解决了这个错误。请参考：http://blog.marcgravell.com/2008/12/astoria-and-linq-to-sql-getting-started.html.

现在我可以通过Odata服务公开实体，但当我试图通过键入URL（例如…/WcfDataService1.svc/Assels）来访问实体集合时，它会引发以下错误：

错误：

 <?xml version="1.0" encoding="utf-8" ?> 
 <m:error xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
   <m:code /> 
   <m:message xml:lang="en-US">An error occurred while processing this request.</m:message> 
   <m:innererror>
     <m:message>Operation could destabilize the runtime.</m:message> 
     <m:type>System.Security.VerificationException</m:type> 
     <m:stacktrace>at queryable_reader(Object ) at   System.Data.Services.Providers.ReflectionServiceProvider.GetQueryRootForResourceSet(ResourceSet container) at System.Data.Services.Providers.ReflectionDataServiceProvider.GetQueryRootForResourceSet(ResourceSet resourceSet) at System.Data.Services.Providers.DataServiceProviderWrapper.GetQueryRootForResourceSet(ResourceSetWrapper resourceSet) at System.Data.Services.RequestUriProcessor.ComposeExpressionForEntitySet(SegmentInfo segment, IDataService service, Boolean isLastSegment, Boolean checkRights) at System.Data.Services.RequestUriProcessor.ComposeExpressionForSegments(IList`1 segments, IDataService service, Boolean isCrossReferencingUri) at System.Data.Services.RequestUriProcessor.ProcessRequestUri(Uri absoluteRequestUri, IDataService service, Boolean internalQuery) at System.Data.Services.DataService`1.ProcessIncomingRequestUri() at System.Data.Services.DataService`1.HandleRequest()</m:stacktrace> 
  </m:innererror>
 </m:error>

如何解决此问题？

谢谢，

Answer 1

要将WCF DataService与EF6一起使用，需要做一些额外的工作。请查看以下两篇博客文章了解详细信息：

将WCF Data Services 5.6.0与实体框架6+一起使用

WCF数据服务实体框架提供程序已使用WCF数据服务5.6.2 更新

一般来说，您需要以下两个步骤：

1. 按照该页面上的指南安装最新的Nuget包Microsoft.OData.EntityFrameworkProvider

2. 用EntityFrameworkDataService替换DataService，比如在您的WcfDataService1.svc:中

   公共类WcfDataService1:EntityFrameworkDataService