Question

我在控制台应用程序中自行托管Odata WCF数据服务，该应用程序通过ADO.Net实体模型连接到Oracle数据库。我正在使用Microsoft.Data.Services v5.5.0。我可以通过客户端应用程序读/写数据，但无法删除。这是代码：

服务器代码：

public class tos_host : DataService<Entities>
{
    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.All);
        config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V3;
    }
}
class Program
{
    static void Main(string[] args)
    {
        Uri[] baseAddresses = new Uri[1];
        baseAddresses[0] = new Uri("http://localhost:4444/tos_host");
        using (DataServiceHost host = new DataServiceHost(typeof(tos_host), baseAddresses))
        {
            host.Open();
            Console.WriteLine("TOS host up and running.....");
            Console.ReadLine();
            host.Close();
        }
    }
}

客户代码：

  static void Main(string[] args)
    {
        Entities context = new Entities(new Uri("http://localhost:4444/tos_host"));
        context.MergeOption = MergeOption.OverwriteChanges;
        context.IgnoreMissingProperties = true;

        var container = new CONTAINERS();
        container.CONTAINER_ID = "CONT";
        container.TIMESTAMP=DateTime.UtcNow;
        context.AddToCONTAINERS(container);
        context.SaveChanges();
        CONTAINERS container_2 = context.CONTAINERS.Where(c => c.CONTAINER_ID == "CONT").First();
        context.DeleteObject(container_2);
        context.SaveChanges();          //Here i get an exception 
    }

例外情况如下：

System.Data.Services.Client.DataServiceRequestException was unhandled
HResult=-2146233079
Message=An error occurred while processing this request.
Source=Microsoft.Data.Services.Client
StackTrace:
     at System.Data.Services.Client.SaveResult.HandleResponse()
     at System.Data.Services.Client.BaseSaveResult.EndRequest()
     at System.Data.Services.Client.DataServiceContext.SaveChanges(SaveChangesOptions options)
     at System.Data.Services.Client.DataServiceContext.SaveChanges()
     at client_test_lnew_libs.Program.Main(String[] args) in c:\Users\ITS\Desktop\rmcs_tests     \client_test_lnew_libs\client_test_lnew_libs\Program.cs:line 27
   at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
   at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
   at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()
   InnerException: System.Data.Services.Client.DataServiceClientException
   HResult=-2146233079
   Message=<?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="el-GR">Resource not found for the segment 'CONTAINERS'.</m:message></m:error>
   StatusCode=404
   InnerException:

我做错了什么？有线索吗？

Answer 1

根据我的理解，当您查询并且没有返回任何结果时，dataservice将抛出您看到的异常。要改为返回空集，需要设置IgnoreResourceNotFoundException属性：

context.IgnoreResourceNotFoundException = true;

有关详细信息，请参阅以下博文：

http://blogs.msdn.com/b/peter_qian/archive/2009/03/20/safe-resource-not-found-404-exception-handling-in-ado-net-data-service-client.aspx?Redirected=true

通过WCF数据服务客户端应用程序删除数据

1 个答案: