Three level hierarchical data-linq

I have three level hierarchical data. using the statement below i managed 开发者_JAVA百科to display two level data. I need to extend it to one more level.

Current hierachy is Modules-->Documents

I need to extend it as Packages-->Modules-->Documents

var data = (from m in DataContext.SysModules
             join d in DataContext.SysDocuments on m.ModuleID equals d.ModuleID into tempDocs
             from SysDocument in tempDocs.DefaultIfEmpty()
             group SysDocument by m).ToList();

Regards Tassadaque

Sometimes the DataLoadOptions route is no good - because additional filtering/ordering may be needed on the child collections. Here's another way to go:

var resultList =
(
  from pack in myDC.SysPackages
  let mods =
  (
    from mod in pack.SysModules.Where(mod => mod.ShouldLoad)
    let docs = mod.SysDocuments.Where(doc => doc.ShouldLoad)
    select new {Module = mod, Documents = docs.ToList()}
  )
  select new {Package = pack, Modules = mods.ToList()}
).ToList();

You should use the DataLoadOptions property on DataContext.

DataLoadOptions dlo = new DataLoadOptions();
  //packages are loaded with their modules...
dlo.LoadWith<SysPackage>(p => p.SysModules);
  // ... which are loaded with their documents.
dlo.LoadWith<SysModule>(m => m.SysDocuments);
myDataContext.LoadOptions = dlo;
List<SysPackage> result = myDataContext.SysPackages.ToList();