Entity Framework (.NET Full Framework) Ordering Includes [duplicate]

I am trying to get something like the following to work:

_dbmsParentSections = FactoryTools.Factory.PdfSections
                        .Include(x => x.Children.OrderBy(y => y.Order).ToList())
                        .Include(x => x.Hint).Include(x => x.Fields)
                        .Where(x => x.FormId == FormId && x.Parent == null)
                        .OrderBy(o => o.Order)
                        .ToList();

The part that causes the exception is:

.Include(x => x.Children.OrderBy(y => y.Order).ToList())

EDIT:

Upon further observation,

_dbmsParentSections.ForEach(x => x.Children = x.Children.OrderBy(y => y.Order).ToList());

did the job for me (after the initial Factory call and without the Children.OrderBy).

Solution 1:

It seems you cannot sort the children collection in your query. Either sort after the query or load the children in a second query.

Similar question and answer here

Solution 2:

According to this documentation, starting with EF Core 5.0, you can sort by a property of your Included Entity:

 await context.Parents
    .OrderBy(parent => parent.Order)
    .Include(parent => parent.Children.OrderBy(child => child.Order))
    .ToListAsync();

The above example sorts Parent entities by their Order, as well as their Children entities by the Children entities' Order property.