使用实体框架实体连接时的MetadataException [英] MetadataException when using Entity Framework Entity Connection

问题描述

此代码

using (EntityConnection conn = new EntityConnection("name=ELSCommonEntities"))
{
  conn.Open();
}

给我以下错误：

Test method ELS.Service.Business.IntegrationTest.Base.ServiceBaseIntegrationTest.StartLoggingTestMethod threw exception:  System.Data.MetadataException: Unable to load the specified metadata resource..

使用以下堆栈跟踪：

System.Data.Metadata.Edm.MetadataArtifactLoaderCompositeResource.LoadResources(String assemblyName, String resourceName, ICollection`1 uriRegistry, MetadataArtifactAssemblyResolver resolver)
System.Data.Metadata.Edm.MetadataArtifactLoaderCompositeResource.CreateResourceLoader(String path, ExtensionCheck extensionCheck, String validExtension, ICollection`1 uriRegistry, MetadataArtifactAssemblyResolver resolver)
System.Data.Metadata.Edm.MetadataArtifactLoader.Create(String path, ExtensionCheck extensionCheck, String validExtension, ICollection`1 uriRegistry, MetadataArtifactAssemblyResolver resolver)
System.Data.EntityClient.EntityConnection.SplitPaths(String paths)
System.Data.EntityClient.EntityConnection.GetMetadataWorkspace(Boolean initializeAllCollections)
System.Data.EntityClient.EntityConnection.InitializeMetadata(DbConnection newConnection, DbConnection originalConnection, Boolean closeOriginalConnectionOnFailure)
System.Data.EntityClient.EntityConnection.Open()
ELS.Service.Business.Base.ServiceBase.StartLogging(String userWindowsLogon) in C:\C-TOM\ELS-RELEASE1\ELS.Service.Business\Base\ServiceBase.cs: line 98
ELS.Service.Business.IntegrationTest.Base.ServiceBaseIntegrationTest.StartLoggingTestMethod() in C:\C-TOM\ELS-RELEASE1\ELS.Service.Business.IntegrationTest\Base\ServiceBaseIntegrationTest.cs: line 65

但是，使用相同连接字符串的代码：

However, this code which uses the same connection string:

using (ELSCommonEntities db = new ELSCommonEntities())
{
    var res = from c in db.Logging
              select c;

    int i = res.Count();
}

不给出错误。

连接字符串是：

<add name="ELSCommonEntities" connectionString="metadata=res://*/Common.CommonModel.csdl|res://*/Common.CommonModel.ssdl|res://*/Common.CommonModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=localhost;Initial Catalog=els5_demo;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />

我还打开了反光板中的dll，元数据看起来很好。

I have also opened up the dll in reflector and the metadata looks ok.

推荐答案

发现问题。

标准元数据字符串如下所示：

The standard metadata string looks like this:

metadata=res://*/Model.csdl|res://*/Model.ssdl|res://*/Model.msl

这在大多数情况下都可以正常工作。但是，在某些（包括我的）实体框架中，实体框架变得困惑，不知道要查找哪个DLL。因此，将元数据字符串更改为：

And this works fine in most cases. However, in some (including mine) Entity Framework get confused and does not know which dll to look in. Therefore, change the metadata string to:

metadata=res://nameOfDll/Model.csdl|res://nameOfDll/Model.ssdl|res://nameOfDll/Model.msl

它会工作。正是这个链​​接让我处于正确的轨道上：

And it will work. It was this link that got me on the right track:

http://itstu.blogspot.com/2008/07/to-load-specified-metadata-resource.html

尽管我遇到了问题，但是在单元测试中没有工作，但在服务中。

Although I had the oposite problem, did not work in unit test, but worked in service.

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