CODEWITHSUNDEEP
c#entity-framework.net-4.5entity-framework-5
ebattulga
ebattulga

Reputation: 10981

DBContext conversion from ObjectContext

I'm use this function in EntityFramework 4.0 (ObjectContext). Now i'm using EF 5.0. My problem is DefaultContainerName,GetObjectByKey methods not found in DBContext

public static T GetObjectByID<T>(int ID, string tableName = "")
        {
            var localDB = new LocalBaseEntities();

            string entitySetName = string.Format("{0}.{1}", localDB.DefaultContainerName, string.IsNullOrEmpty(tableName) ? typeof(T).Name + "s" : tableName);

            try
            {
                IEnumerable<KeyValuePair<string, object>> entityKeyValues =
                new KeyValuePair<string, object>[] { new KeyValuePair<string, object>(typeof(T).Name + "ID", ID) };
                EntityKey key = new System.Data.EntityKey(entitySetName, entityKeyValues);            
                return (T)localDB.GetObjectByKey(key);
            }
            catch (Exception)
            { }            

            return default(T);
        }

How to convert this function?

Or how to make function like this?

Upvotes: 5

Views: 7831

Answers (1)

Sergey Berezovskiy
Sergey Berezovskiy

Reputation: 236188

DbContext is an adapter (wrapper) over ObjectContext. Also it implements explicitly interface IObjectContextAdapter. Cast you dbContext to this interface type and wrapped ObjectContext instance will be available:

ObjectContext context = ((IObjectContextAdapter)dbContext).ObjectContext;

BTW new class DbSet<T> has method Find which also searches entities by key. So, it seems all your code now will look like 

T entity = dbContext.Set<T>().Find(id);

Upvotes: 15

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