How to get the primarykey name of the table in EntityFramework C#?

 Here is how to get the primary key of an entitySetName
var primaryKeyName = objDb
   .MetadataWorkspace
   .GetEntityContainer(objDb.DefaultContainerName, System.Data.Metadata.Edm.DataSpace.CSpace)
   .BaseEntitySets
   .First(meta => meta.ElementType.Name == entitySetName)
   .ElementType
   .KeyMembers
   .Select(k => k.Name)
   .FirstOrDefault();