Adding a matching condition for a child collection in Entity Framework 6, similar to NHibernate "where"

Question

NHibernate has a mapping wherethat allows you to specify a condition for a property mapping that affects how it is retrieved from the database. For example, if I wanted to implement soft deletion and exclude all deleted items from the set, I could display it like this:

Fluentnhibernate

// in class ParentMap : ClassMap
HasMany(x => x.Children).Where("IsDeleted = 0");

hbm.xml

<class name="Parent" table="[Parents]">
    <bag cascade="all" lazy="true" name="Children" where="IsDeleted = 0">
        <!-- rest of map here -->
    </bag>
</class>

Is there something similar in Entity Framework 6?

The closest I found is a library called EntityFramework.Filters , which allows you to add global filters for a property, but it doesn't seem to work when this property is a collection.

---

, , , , , (.. ). :

public class ReportOutline
{
    public long Id { get; set; }
    public string Title { get; set; }
    public string Author { get; set; }    
    public virtual ICollection<OutlineItem> OutlineItems { get; set; }
}

public class OutlineItem
{
    public long Id { get; set; }
    public string Name { get; set; }

    public long ReportOutlineId { get; set; }
    public long? ParentOutlineItemId { get; set; }    

    public virtual ReportOutline ReportOutline { get; set; }
    public virtual OutlineItem ParentOutlineItem { get; set; }    

    public virtual ICollection<OutlineItem> OutlineItems { get; set; }
}

API- EF, :

modelBuilder.Entity<ReportOutline>()
    .HasKey(o => o.Id)
    .HasMany(o => o.OutlineItems)
    .WithRequired(i => i.ReportOutline)
    .HasForeignKey(i => i.OutlineId);

modelBuilder.Entity<OutlineItem>()
    .HasKey(p => p.Id)
    .HasMany(p => p.OutlineItems)
    .WithOptional(c => c.ParentOutlineItem)
    .HasForeignKey(c => c.ParentOutlineItemId);

, . , OutlineItems ReportOutline, ( ):

Id    Name           ReportOutlineId    ParentOutlineItemId
1     Introduction   1                  NULL
2     Pets           1                  NULL
3     Cats           1                  2
4     Dogs           1                  2

ReportOutline DbContext, , ReportOutlineId Id, ReportOutline.OutlineItems . , , :

Title:  My Report
Author: valverij

I.  Introduction  (Id: 1)
II. Pets          (Id: 2)
    A. Cats       (Id: 3)
    B. Dogs       (Id: 4)
III. Cats         (Id: 3) <--- Duplicated
IV.  Dogs         (Id: 4) <--- Duplicated

, NHibernate FluentNhibernate, where , ReportOutline.OutlineItems :

// in ReportOutlineMap
HasMany(x => x.OutlineItems).Where("ParentOutlineItemId IS NULL");

ReportOutline , OutlineItem.

Answer 1

RootOutlineItems ReportOutline, , , 1- :

public class ReportOutline
{
    public long Id { get; set; }
    public string Title { get; set; }
    public string Author { get; set; }    
    public virtual ICollection<OutlineItem> OutlineItems { get; set; }
    public ICollection<OutlineItem> RootOutlineItems { 
        get {
            return OutlineItems.Where(p=> p.ParentOutlineItem == null);
        }
    }
}

- OutlineItem ReportOutline - ReportOutline ParentOutlineItem, , , - .