实体框架通过自身顺序获取带有子集合的实体

Question

I have a entity(SystemUnit), which contains collection of sub entities(Roles):

public partial class SystemUnit
{
    public SystemUnit()
    {
        this.Roles = new HashSet<Role>();
        this.Childs = new HashSet<SystemUnit>();
    }

    public int Id { get; set; }
    public Nullable<int> ParentId { get; set; }
    public int SystemUnitTypeId { get; set; }
    public string Name { get; set; }

    public virtual SystemUnitType SystemUnitType { get; set; }
    public virtual ICollection<Role> Roles { get; set; }
    public virtual ICollection<SystemUnit> Childs { get; set; }
    public virtual SystemUnit Parent { get; set; }
}

I need using entity framework to get all system units, ordered by Id Asc with included Roles, ordered by id desc. Newbee in linq (

Answer 1

The Roles included according to SystemUnit objects. If SystemUnit object has Id ordered by desc so in this way roles can not be orderby dec. They will retrieve according to SystemUnit objects

Answer 2

For this you need a context entity first and then add your system unit entity as an object in it. For example:

public class entityContext{

    public DbSet<SystemUnit> SystemUnit { get; set;}

}

And then in your method where you need to call the entity, write:

entityContext ec = new entityContext();
 List<SystemUnit> systemUnit = (from su in ec.SystemUnit .Include("Roles") orderby su.Id Asc).ToList();