用于嵌套导航属性的实体框架“包含”会产生比预期更多的数据

Question

private IQueryable<MyEntity> GetEntities(MyDataContext dc)
{
    return dc.MyEntities.Include(
        entity => entity.RelationalEntities.Select(
            relationalEntity => relationalEntity.ChildEntities
        )
    );
}

At a glance, this appears correct.

However, after taking a closer look at the data returned, we find that ChildEntities incorrectly contains a collection of all relations in the relational table, even though it should only contain ChildEntity entries that relate to the entity object referred to by the RelationalEntity table.

To put it simply, we are getting more ChildEntity entries than expected from this query, and there does not appear to be a way to filter on them by using .Where() in these .Include() calls due to framework limitations.

Ideally, I would be able to extend the query as follows, but this code results in Entity Framework exceptions:

private IQueryable<MyEntity> GetEntities(RcmEntities dc)
{
    return dc.MyEntities.Include(
        entity => entity.RelationalEntity.Select(
            relationalEntity => relationalEntity.ChildEntities.Where(
                childEntity => childEntity.MyEntityId == entity.MyEntityId
                 && childEntity.ChildEntityId == relationalEntity.ChildEntityId
            )
        )
    );
}

The table relation looks something like this:

MyEntity.MyEntityId -> RelationalEntity.MyEntityId, RelationalEntity.ChildEntityId -> ChildEntity.ChildEntityId

How can I adjust this Entity Framework query to only return ChildEntity entries that relate to the referred MyEntity entry?

Edit 1:

By request, here is an exact copy of our entity classes, with all domain-specific information removed:

namespace TransportTypes
{
    using Newtonsoft.Json;

    // Entity
    [System.CodeDom.Compiler.GeneratedCode("EF.Reverse.POCO.Generator", "2.37.4.0")]
    public partial class Entity
    {
        public int EntityId { get; set; } // EntityId (Primary key)
        
        // Removed domain-specific fields...

        // Reverse navigation

        /// <summary>
        /// Child ChildEntitys (Many-to-Many) mapped by table [EntityEnabledChild]
        /// </summary>
        [JsonIgnore]
        public virtual System.Collections.Generic.ICollection<ChildEntity> ChildEntitys { get; set; } = new System.Collections.Generic.List<ChildEntity>(); // Many to many mapping
        /// <summary>
        /// Child ChildEntityContents where [ChildEntityContent].[EntityId] point to this entity (FK_ChildEntityContent_Entity)
        /// </summary>
        [JsonIgnore]
        public virtual System.Collections.Generic.ICollection<ChildEntityContent> ChildEntityContents { get; set; } = new System.Collections.Generic.List<ChildEntityContent>(); // ChildEntityContent.FK_ChildEntityContent_Entity
    }

    // Entity
    [System.CodeDom.Compiler.GeneratedCode("EF.Reverse.POCO.Generator", "2.37.4.0")]
    public partial class EntityConfiguration : System.Data.Entity.ModelConfiguration.EntityTypeConfiguration<Entity>
    {
        public EntityConfiguration()
            : this("dbo")
        {
        }

        public EntityConfiguration(string schema)
        {
            ToTable("Entity", schema);
            HasKey(x => x.EntityId);

            Property(x => x.EntityId).HasColumnName(@"EntityId").HasColumnType("int").IsRequired().HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Identity);
            HasMany(t => t.ChildEntitys).WithMany(t => t.Entitys).Map(m =>
            {
                m.ToTable("EntityEnabledChild", "dbo");
                m.MapLeftKey("EntityId");
                m.MapRightKey("ChildEntityId");
            });
            InitializePartial();
        }
        partial void InitializePartial();
    }

    // ChildEntity
    [System.CodeDom.Compiler.GeneratedCode("EF.Reverse.POCO.Generator", "2.37.4.0")]
    public partial class ChildEntity
    {
        public int ChildEntityId { get; set; } // ChildEntityId (Primary key)

        // Reverse navigation

        /// <summary>
        /// Child Entitys (Many-to-Many) mapped by table [EntityEnabledChild]
        /// </summary>
        [JsonIgnore]
        public virtual System.Collections.Generic.ICollection<Entity> Entitys { get; set; } = new System.Collections.Generic.List<Entity>(); // Many to many mapping
        /// <summary>
        /// Child ChildEntityContents where [ChildEntityContent].[ChildEntityId] point to this entity (FK_ChildEntityContent_ChildEntity)
        /// </summary>
        [JsonIgnore]
        public virtual System.Collections.Generic.ICollection<ChildEntityContent> ChildEntityContents { get; set; } = new System.Collections.Generic.List<ChildEntityContent>(); // ChildEntityContent.FK_ChildEntityContent_ChildEntity
    }

    // ChildEntity
    [System.CodeDom.Compiler.GeneratedCode("EF.Reverse.POCO.Generator", "2.37.4.0")]
    public partial class ChildEntityConfiguration : System.Data.Entity.ModelConfiguration.EntityTypeConfiguration<ChildEntity>
    {
        public ChildEntityConfiguration()
            : this("dbo")
        {
        }

        public ChildEntityConfiguration(string schema)
        {
            ToTable("ChildEntity", schema);
            HasKey(x => x.ChildEntityId);

            Property(x => x.ChildEntityId).HasColumnName(@"ChildEntityId").HasColumnType("int").IsRequired().HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.None);
            InitializePartial();
        }
        partial void InitializePartial();
    }

    // ChildEntityContent
    [System.CodeDom.Compiler.GeneratedCode("EF.Reverse.POCO.Generator", "2.37.4.0")]
    public partial class ChildEntityContent
    {
        public int EntityId { get; set; } // EntityId (Primary key)
        public int ChildEntityId { get; set; } // ChildEntityId (Primary key)
        public string ContentKey { get; set; } // ContentKey (Primary key) (length: 100)
        public string ContentValue { get; set; } // ContentValue

        // Foreign keys

        /// <summary>
        /// Parent Entity pointed by [ChildEntityContent].([EntityId]) (FK_ChildEntityContent_Entity)
        /// </summary>
        [JsonIgnore]
        public virtual Entity Entity { get; set; } // FK_ChildEntityContent_Entity

        /// <summary>
        /// Parent ChildEntity pointed by [ChildEntityContent].([ChildEntityId]) (FK_ChildEntityContent_ChildEntity)
        /// </summary>
        [JsonIgnore]
        public virtual ChildEntity ChildEntity { get; set; } // FK_ChildEntityContent_ChildEntity
    }

    // ChildEntityContent
    [System.CodeDom.Compiler.GeneratedCode("EF.Reverse.POCO.Generator", "2.37.4.0")]
    public partial class ChildEntityContentConfiguration : System.Data.Entity.ModelConfiguration.EntityTypeConfiguration<ChildEntityContent>
    {
        public ChildEntityContentConfiguration()
            : this("dbo")
        {
        }

        public ChildEntityContentConfiguration(string schema)
        {
            ToTable("ChildEntityContent", schema);
            HasKey(x => new { x.EntityId, x.ChildEntityId, x.ContentKey });

            Property(x => x.EntityId).HasColumnName(@"EntityId").HasColumnType("int").IsRequired().HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.None);
            Property(x => x.ChildEntityId).HasColumnName(@"ChildEntityId").HasColumnType("int").IsRequired().HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.None);
            Property(x => x.ContentKey).HasColumnName(@"ContentKey").HasColumnType("nvarchar").IsRequired().HasMaxLength(100).HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.None);
            Property(x => x.ContentValue).HasColumnName(@"ContentValue").HasColumnType("nvarchar(max)").IsOptional();

            // Foreign keys
            HasRequired(a => a.Entity).WithMany(b => b.ChildEntityContents).HasForeignKey(c => c.EntityId).WillCascadeOnDelete(false); // FK_ChildEntityContent_Entity
            HasRequired(a => a.ChildEntity).WithMany(b => b.ChildEntityContents).HasForeignKey(c => c.ChildEntityId).WillCascadeOnDelete(false); // FK_ChildEntityContent_ChildEntity
            InitializePartial();
        }
        partial void InitializePartial();
    }
}

Answer 1

If this is EF 6 then it should look like:

return dc.MyEntities
    .Include(entity => entity.RelationalEntities)
    .Include(entity => entity.RelationalEntities
        .Select(rentity => rentity.ChildEntities))
    .AsQueryable();

Your second example would be involving conditional, or filtered includes which are only supported in EF Core, in which case I believe it should be:

return dc.MyEntities
    .Include(entity => entity.RelationalEntities)
       .ThenInclude(rentity => rentity.ChildEntities)
    .AsQueryable();

Beyond that it would depend on your specific entity definitions to ensure that your relationships between Entity, RelationalEntity, and ChildEntity are configured as proper 1-to-many or many-to-many relationships and not doing something unconventional resulting in them being too loosely associated resulting in unexpected query results.