I'm trying to setup a very simple test project to evaluate Mono Entity Framework capabilities. When trying to access data, I get a runtime exception about parsing the model data when using .NET Runtime. When using Mono runtime, a stackoverflow exception is thrown.
This seems to be an internal mono bug which occurs when compiling the CSDL Schema Version 3 - see Mono Bugtracker.
So my question is:
How do I setup Mono with Entity Framework to work with a Microsoft SQL Server? Since I don't find much information, should this even be possible? Did anyone of you successfully setup a mono solution using EF and came across similar errors?
This is what I have done so far:
- Installed Mono 3.0.1 Beta (latest stable doesn't include
EntityFramework.dll
) - Setup a Mono Profile for Visual Studio
- Disabled strong name verification for delay signed assembilies for
EntityFramework.dll
/EntityFramework.SQLServer.dll
and added them to the GAC to prevent runtime errors - Created a simple model + added Code Generation Items
- written code using the model
The code works with Microsoft EntityFramework.dll
(Version 6, Prerelease). When using the Mono equivalent, it looks like there are problems while parsing the entity model:
Exception message (.NET Runtime):
Object reference not set to an instance of an object.
Stacktrace (.NET Runtime):
at System.Xml.XmlTextReaderImpl.InitStreamInput(Uri baseUri, String baseUriStr, Stream stream, Byte[] bytes, Int32 byteCount, Encoding encoding)
at System.Xml.XmlTextReaderImpl..ctor(String url, Stream input, XmlNameTable nt)
at System.Xml.XmlTextReader..ctor(Stream input)
at System.Data.Entity.Core.EntityModel.SchemaObjectModel.Schema.SomSchemaSetHelper.AddXmlSchemaToSet(XmlSchemaSet schemaSet, XmlSchemaResource schemaResource, HashSet`1 schemasAlreadyAdded)
at System.Data.Entity.Core.EntityModel.SchemaObjectModel.Schema.SomSchemaSetHelper.AddXmlSchemaToSet(XmlSchemaSet schemaSet, XmlSchemaResource schemaResource, HashSet`1 schemasAlreadyAdded)
at System.Data.Entity.Core.EntityModel.SchemaObjectModel.Schema.SomSchemaSetHelper.ComputeSchemaSet(SchemaDataModelOption dataModel)
at System.Data.Entity.Core.Common.Utils.Memoizer`2.Result.GetValue()
at System.Data.Entity.Core.Common.Utils.Memoizer`2.Evaluate(TArg arg)
at System.Data.Entity.Core.EntityModel.SchemaObjectModel.Schema.SomSchemaSetHelper.GetSchemaSet(SchemaDataModelOption dataModel)
at System.Data.Entity.Core.EntityModel.SchemaObjectModel.Schema.Parse(XmlReader sourceReader, String sourceLocation)
at System.Data.Entity.Core.EntityModel.SchemaObjectModel.SchemaManager.ParseAndValidate(IEnumerable`1 xmlReaders, IEnumerable`1 sourceFilePaths, SchemaDataModelOption dataModel, AttributeValueNotification providerNotification, AttributeValueNotification providerManifestTokenNotification, ProviderManifestNeeded providerManifestNeeded, IList`1& schemaCollection)
at System.Data.Entity.Core.Metadata.Edm.StoreItemCollection.Loader.LoadItems(IEnumerable`1 xmlReaders, IEnumerable`1 sourceFilePaths)
at System.Data.Entity.Core.Metadata.Edm.StoreItemCollection.Init(IEnumerable`1 xmlReaders, IEnumerable`1 filePaths, Boolean throwOnError, DbProviderManifest& providerManifest, DbProviderFactory& providerFactory, String& providerManifestToken, Memoizer`2& cachedCTypeFunction)
at System.Data.Entity.Core.Metadata.Edm.StoreItemCollection..ctor(IEnumerable`1 xmlReaders, IEnumerable`1 filePaths)
at System.Data.Entity.Core.Metadata.Edm.MetadataCache.StoreMetadataEntry.LoadStoreCollection(EdmItemCollection edmItemCollection, MetadataArtifactLoader loader)
at System.Data.Entity.Core.Metadata.Edm.MetadataCache.LoadItemCollection[T](IItemCollectionLoader`1 itemCollectionLoader, T entry)
at System.Data.Entity.Core.Metadata.Edm.MetadataCache.GetOrCreateStoreAndMappingItemCollections(String cacheKey, MetadataArtifactLoader loader, EdmItemCollection edmItemCollection, Object& entryToken)
at System.Data.Entity.Core.EntityClient.EntityConnection.LoadStoreItemCollections(MetadataWorkspace workspace, DbConnection storeConnection, DbConnectionOptions connectionOptions, EdmItemCollection edmItemCollection, MetadataArtifactLoader artifactLoader)
at System.Data.Entity.Core.EntityClient.EntityConnection.GetMetadataWorkspace(Boolean initializeAllCollections)
at System.Data.Entity.Core.EntityClient.EntityConnection.InitializeMetadata(DbConnection newConnection, DbConnection originalConnection, Boolean closeOriginalConnectionOnFailure)
at System.Data.Entity.Core.EntityClient.EntityConnection.Open()
at System.Data.Entity.Core.Objects.ObjectContext.EnsureConnection()
at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
at System.Data.Entity.Core.Objects.ObjectQuery`1.<GetEnumerator>m__2C3()
at System.Lazy`1.CreateValue()
at System.Lazy`1.LazyInitValue()
at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source)
at System.Linq.Queryable.Count[TSource](IQueryable`1 source)
at EntityFrameworkMono.Program.Main(String[] args) in c:\Users\Christopher Dresel\Documents\Visual Studio 2012\Projects\New\EntityFrameworkMono\EntityFrameworkMono\Program.cs:line 17
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
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()
Exception message (Mono Runtime):
The requested operation caused a stack overflow.
Stacktrace (Mono Runtime):
at System.Xml.Schema.XmlSchemaGroupBase.CheckRecursion (Int32 depth, System.Xml.Schema.ValidationEventHandler h, System.Xml.Schema.XmlSchema schema) [0x00000] in <filename unknown>:0
at System.Xml.Schema.XmlSchemaGroupBase.CheckRecursion (Int32 depth, System.Xml.Schema.ValidationEventHandler h, System.Xml.Schema.XmlSchema schema) [0x00000] in <filename unknown>:0
at System.Xml.Schema.XmlSchemaElement.CheckRecursion (Int32 depth, System.Xml.Schema.ValidationEventHandler h, System.Xml.Schema.XmlSchema schema) [0x00000] in <filename unknown>:0
at System.Xml.Schema.XmlSchemaGroupBase.CheckRecursion (Int32 depth, System.Xml.Schema.ValidationEventHandler h, System.Xml.Schema.XmlSchema schema) [0x00000] in <filename unknown>:0
at System.Xml.Schema.XmlSchemaGroupBase.CheckRecursion (Int32 depth, System.Xml.Schema.ValidationEventHandler h, System.Xml.Schema.XmlSchema schema) [0x00000] in <filename unknown>:0
at System.Xml.Schema.XmlSchemaElement.CheckRecursion (Int32 depth, System.Xml.Schema.ValidationEventHandler h, System.Xml.Schema.XmlSchema schema) [0x00000] in <filename unknown>:0
at System.Xml.Schema.XmlSchemaGroupBase.CheckRecursion (Int32 depth, System.Xml.Schema.ValidationEventHandler h, System.Xml.Schema.XmlSchema schema) [0x00000] in <filename unknown>:0
at System.Xml.Schema.XmlSchemaGroupBase.CheckRecursion (Int32 depth, System.Xml.Schema.ValidationEventHandler h, System.Xml.Schema.XmlSchema schema) [0x00000] in <filename unknown>:0
...
This is the code I'm using:
CustomerEntities entities = new CustomerEntities();
var count = entities.Customers.Count(); // Exception throws here
Console.WriteLine(count);
Console.ReadKey();
EDMX
file
<?xml version="1.0" encoding="utf-8"?>
<edmx:Edmx Version="3.0" xmlns:edmx="http://schemas.microsoft.com/ado/2009/11/edmx">
<!-- EF Runtime content -->
<edmx:Runtime>
<!-- SSDL content -->
<edmx:StorageModels>
<Schema Namespace="CustomerModel.Store" Alias="Self" Provider="System.Data.SqlClient" ProviderManifestToken="2008" xmlns="http://schemas.microsoft.com/ado/2009/11/edm/ssdl">
<EntityContainer Name="CustomerModelStoreContainer">
<EntitySet Name="Customer" EntityType="CustomerModel.Store.Customer" store:Type="Tables" Schema="dbo" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" />
</EntityContainer>
<EntityType Name="Customer">
<Key>
<PropertyRef Name="CustomerID" />
</Key>
<Property Name="CustomerID" Type="int" Nullable="false" StoreGeneratedPattern="Identity" />
<Property Name="CustomerName" Type="nvarchar" Nullable="false" MaxLength="50" />
</EntityType>
</Schema>
</edmx:StorageModels>
<!-- CSDL content -->
<edmx:ConceptualModels>
<Schema Namespace="CustomerModel" Alias="Self" annotation:UseStrongSpatialTypes="false" xmlns="http://schemas.microsoft.com/ado/2009/11/edm" xmlns:annotation="http://schemas.microsoft.com/ado/2009/02/edm/annotation">
<EntityContainer Name="CustomerEntities" annotation:LazyLoadingEnabled="true">
<EntitySet Name="Customers" EntityType="CustomerModel.Customer" />
</EntityContainer>
<EntityType Name="Customer">
<Key>
<PropertyRef Name="CustomerID" />
</Key>
<Property Name="CustomerID" Type="Int32" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
<Property Name="CustomerName" Type="String" Nullable="false" MaxLength="50" Unicode="true" FixedLength="false" />
</EntityType>
</Schema>
</edmx:ConceptualModels>
<!-- C-S mapping content -->
<edmx:Mappings>
<Mapping Space="C-S" xmlns="http://schemas.microsoft.com/ado/2009/11/mapping/cs">
<EntityContainerMapping StorageEntityContainer="CustomerModelStoreContainer" CdmEntityContainer="CustomerEntities">
<EntitySetMapping Name="Customers">
<EntityTypeMapping TypeName="CustomerModel.Customer">
<MappingFragment StoreEntitySet="Customer">
<ScalarProperty Name="CustomerID" ColumnName="CustomerID" />
<ScalarProperty Name="CustomerName" ColumnName="CustomerName" />
</MappingFragment>
</EntityTypeMapping>
</EntitySetMapping>
</EntityContainerMapping>
</Mapping>
</edmx:Mappings>
</edmx:Runtime>
</edmx:Edmx>
And finally the connection string I'm using:
<connectionStrings>
<add name="CustomerEntities"
connectionString="metadata=.\CustomerModel.csdl|.\CustomerModel.ssdl|.\CustomerModel.msl;provider=System.Data.SqlClient;provider connection string="data source=CHRISTOPHERPC\SQLExpress;initial catalog=test;integrated security=True;MultipleActiveResultSets=True;App=EntityFramework""
providerName="System.Data.EntityClient"/>
</connectionStrings>