MetadataException when using Entity Framework Entity Connection

Question

This code   using  EntityConnection conn   new EntityConnection  name ELSCommonEntities        conn Open        Gives me the following error   Test method ELS Service Business IntegrationTest Base ServiceBaseIntegrationTest StartLoggingTestMethod threw exception   System Data MetadataException  Unable to load the specified metadata resource     With the following stack trace   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   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        Does not give an error    The connection string is    lt add name  ELSCommonEntities  connectionString  metadata res     Common CommonModel csdl res     Common CommonModel ssdl res     Common CommonModel msl provider System Data SqlClient provider connection string  amp quot Data Source localhost Initial Catalog els5 demo Integrated Security True MultipleActiveResultSets True amp quot   providerName  System Data EntityClient    gt    I have also opened up the dll in reflector and the metadata looks ok

User · Answer

I had the same problem with three projects in one solution and all of the suggestions didn t work until I made a reference in the reference file of the web site project to the project where the edmx file sits

User · Answer

There are several possible catches  I think that the most common error is in this part of the connection string      res   xxx yyy csdl res   xxx yyy ssdl res   xxx yyy msl    This is no magic  Once you understand what is stands for you ll get the connection string right   First the xxx part  That s nothing else than an assembly name where you defined you EF context clas  Usually it would be something like MyProject Data  Default value is   which stands for all loaded assemblies  It s always better to specify a particular assembly name   Now the yyy part  That s a resource name in the xxx assembly  It will usually be something like a relative path to your  edmx file with dots instead of slashes  E g  Models Catalog - Models Catalog The easiest way to get the correct string for your application is to build the xxx assembly  Then open the assembly dll file in a text editor  I prefer the Total Commander s default viewer  and search for   csdl   Usually there won t be more than 1 occurence of that string   Your final EF connection string may look like this      res   MyProject Data Models Catalog DataContext csdl res   MyProject Data Models Catalog DataContext ssdl res   MyProject Data Models Catalog DataContext msl

User · Answer

I had this problem when moving my  edmx database first model from one project to another   I simply did the following    Deleted the connection strings in the app config or web config Deleted the  Model edmx  Re-added the model to the project

User · Answer

As Shiraz Bhaiji answered  the metadata res    Model csdl res    Model ssdl res     Model msl was the case   However I still had problems with constructing the proper string based on my Model localization  namespaces and assemby name  The very simple solution was to rename the  edmx file in Visual Studio after than rename and get back to the original name   which triggered the automatic refreshing of the string in my Web config

User · Answer

I moved my Database First DataModel to a different project midway through development  Poor planning  or lack there of  on my part    Initially I had a solution with one project  Then I added another project to the solution and recreated my Database First DataModel from the Sql Server Dataase    To fix the problem - MetadataException when using Entity Framework Entity Connection  I copied my the ConnectionString from the new Project Web Config to the original project Web Config  However  this occurred after I updated my all the references in the original project to new DataModel project

User · Answer

It might just be a connection string error  which is solved by the above process  but if you are using the dll s in multiple projects then making sure the connection string is named properly will fix the error for sure

User · Answer

Found the problem   The standard metadata string looks like this   metadata res     Model csdl res     Model ssdl res     Model msl   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   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  Although I had the oposite problem  did not work in unit test  but worked in service

User · Answer

I had the same error message  and the problem was also the metadata part of the connection string  but I had to dig a little deeper to solve it and wanted to share this little nugget   The metadata string is made up of three sections that each look like this   res           assembly          model name   ext    Where ext is  csdl    ssdl   and  msl    For most people  assembly can probably be      which seems to indicate that all loaded assemblies will be searched  I haven t done a huge amount of testing of this   This part wasn t an issue for me  so I can t comment on whether you need the assembly name or file name  i e   with or without   dll    though I have seen both suggested   The model name part should be the name and namespace of your  edmx file  relative to your assembly  So if you have a My DataAccess assembly and you create DataModels edmx in a Models folder  its full name is My DataAccess Models DataModels  In this case  you would have  Models DataModels  ext   in your metadata   If you ever move or rename your  edmx file  you will need to update your metadata string manually  in my experience   and remembering to change the relative namespace will save a few headaches

[entity-framework] MetadataException when using Entity Framework Entity Connection

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