IBaseRepository.cs

using System.Collections.Generic;
using System.Threading.Tasks;

namespace NorthwindApi.Model.Repository
{
    public interface IBaseRepository<T>
        where T : class
    {
        Task<int> Save(T obj);
        Task<int> Update(T obj);
        Task<int> Delete(T obj);
        Task<IList<T>> GetAll();
    }
}