Getting last inserted row id using repository pattern - asp.net-mvc-3

Question

I'm new to this repository pattern. I have the following methods in repository.
public abstract class Repository<T> : IRepository<T> where T : class
{
private PHOnlineEntities dataContext;
private readonly IDbSet<T> dbset;
protected Repository(IDatabaseFactory databaseFactory)
{
DatabaseFactory = databaseFactory;
dbset = DataContext.Set<T>();
}
protected IDatabaseFactory DatabaseFactory
{
get;
private set;
}
protected PHOnlineEntities DataContext
{
get { return dataContext ?? (dataContext = DatabaseFactory.Get()); }
}
public virtual int Add(T entity)
{
dbset.Add(entity);
dataContext.SaveChanges();
// return id here
}
public virtual void Update(T entity)
{
dbset.Attach(entity);
dataContext.Entry(entity).State = EntityState.Modified;
}
public virtual void Delete(T entity)
{
dbset.Remove(entity);
}
public virtual void Delete(Expression<Func<T, bool>> where)
{
IEnumerable<T> objects = dbset.Where<T>(where).AsEnumerable();
foreach (T obj in objects)
dbset.Remove(obj);
}
public virtual T GetById(long id)
{
return dbset.Find(id);
}
public virtual T GetById(string id)
{
return dbset.Find(id);
}
public virtual IEnumerable<T> GetAll()
{
return dbset.ToList();
}
public virtual IEnumerable<T> GetMany(Expression<Func<T, bool>> where)
{
return dbset.Where(where).ToList();
}
public T Get(Expression<Func<T, bool>> where)
{
return dbset.Where(where).FirstOrDefault<T>();
}
This is my CustomerRepository class
public interface ICustomerDetailRepository : IRepository<CustomerDetail>
{
}
/// <summary>
/// CustomerDetail repository
/// </summary>
public class CustomerDetailRepository : Repository<CustomerDetail>, ICustomerDetailRepository
{
/// <summary>
///
/// </summary>
private PHOnlineEntities _dataContext;
/// <summary>
///
/// </summary>
protected IDatabaseFactory DatabaseFactory
{
get;
private set;
}
/// <summary>
///
/// </summary>
/// <param name="databaseFactory"></param>
public CustomerDetailRepository(IDatabaseFactory databaseFactory)
: base(databaseFactory)
{
DatabaseFactory = databaseFactory;
}
/// <summary>
///
/// </summary>
protected PHOnlineEntities DataContext
{
get { return _dataContext ?? (_dataContext = DatabaseFactory.Get()); }
}
}
CustomerDetail class contains Model. It has all the Entity column along with ID column.
When i Add the entity to database, i want to return last inserted row id. The Id is identity column. Could anyone help me on this?

Answer 1

Check your CustomerDetail object after inserting, the ID will be populated already
public class CustomerDetail
{
public int Id{ get; set; }
public string Name{ get; set; }
public string Address{ get; set; }
}
var customerDetail = new CustomerDetail { Name = "Bubbles", Address = "1 way, city" }
customerDetailRepository.Add(customerDetail)
Console.WriteLine(customerDetail.Id); // This is the identity value

Answer 2

You have to create an interface like that:
public interface IEntity
{
public int Id { get; set;}
}
Make your entities implement that interface and change your repository class:
public abstract class Repository<T> : IRepository<T> where T : class, IEntity
{
(...)
public virtual int Add(T entity)
{
dbset.Add(entity);
dataContext.SaveChanges();
// return id here
return entity.Id;
}
}