Entity Framework

ModelMetadata can be generated automatically from an EDMX file or a Code-First DbContext, using the LazyEntityGraph.EntityFramework library.

For each method, the MetadataWorkspace is retrieved using Entity Framework, and then processed to extract entity types and relationships. The MetadataWorkspace is cached as a private static member per context.

EDMX

To generate metadata from an EDMX, call ModelMetadataGenerator.LoadFromEdmxContext<TContext>(string contextName) (source).

The contextName argument is the name of your EDMX model. You can find this in the metadata part of your connection string; for example, if your connection string contains metadata=res://*/MyContextName.csdl|res://*/MyContextName.ssdl|res://*/MyContextName.msl then the context name is MyContextName.

Code-First

To generate metadata from a Code-First DbContext, call ModelMetadataGenerator.LoadFromCodeFirstContext<TContext>(Func<string, TContext> createFromConnectionString, bool hardCache) (source).

The function to be passed to this method must pass the input string to the DbContext's constructor, which should then call base(string nameOrConnectionString). This is so that the DbContext can be instantiated without initializing a connection to the database. This method then uses Entity Framework's EdmxWriter to write the DbContext out to an in-memory XML stream, then processes the XML manually to generate the MetadataWorkspace.

The call to EdmxWriter.WriteEdmx can take a long time. For this reason, the method provides a boolean flag, hardCache, which will write the generated EDMX file to disk when set to true. It uses the most recent DbMigration as a file name, so every time the model is updated the EDMX file is regenerated.