public class Catalog
{
    public virtual int Id { get; set; }
    public virtual string Articule { get; set; }
}
public class A : Catalog
{
    public virtual string Name { get; set; }
    public virtual ICollection<ADictOil> ADictOil { get; set; }
}
public class DictOil
{
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
}
public class ADictOil
{
    public virtual int Id { get; set; }
    public virtual A A { get; set; }
    public virtual DictOil DictOil { get; set; }
}

// MAPPING FLUENT
public class CatalogMap : ClassMap<Catalog>
{
    public CatalogMap()
    {
         Schema("dbo");
         Table("Catalog");
         Id(p => p.Id).Column("Id");
         Map(p => p.Articule).Column("Articule");
    }
}
public class AMap : SubclassMap<A>
{
    public AMap()
    {
         Schema("dbo");
         Table("A");
         KeyColumn("Id");

         Map(p => p.Name).Column("Name");
         HasMany(x => x.ADictOil).KeyColumn("AId");
    }
}
public class DictOilMap : ClassMap<DictOil>
{
    public DictOilMap()
    {
         Schema("dbo");
         Table("DictOil");

         Id(p => p.Id).Column("Id");
         Map(p => p.Name).Column("Name");
    }
}
public class ADictOilMap : ClassMap<ADictOil>
{
      public ADictOilMap()
      {
            Schema("dbo");
            Table("ADictOil");
            Id(p => p.Id).Column("Id");

            References(x => x.A).Column("AId");
            References(x => x.DictOil).Column("DictOilId");
      }
}

-- Catalog
CREATE TABLE [dbo].[Catalog](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[Articule] [int] NULL,
 CONSTRAINT [PK_dbo.Catalog] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
-- A
CREATE TABLE [dbo].[A](
	[Id] [int] NOT NULL,
	[Name] [nvarchar](50) NULL,
 CONSTRAINT [PK_A] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[A]  WITH CHECK ADD  CONSTRAINT [FK_dbo.A_dbo.Catalog_CatalogId] FOREIGN KEY([Id])
REFERENCES [dbo].[Catalog] ([Id])
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[A] CHECK CONSTRAINT [FK_dbo.A_dbo.Catalog_CatalogId]
GO
-- ADictOil
CREATE TABLE [dbo].[ADictOil](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[AId] [int] NOT NULL,
	[DictOilId] [int] NOT NULL,
 CONSTRAINT [PK_dbo.ADictOil] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[ADictOil]  WITH CHECK ADD  CONSTRAINT [FK_ADictOi_AIdl_A_Id] FOREIGN KEY([AId])
REFERENCES [dbo].[A] ([Id])
GO
ALTER TABLE [dbo].[ADictOil] CHECK CONSTRAINT [FK_ADictOi_AIdl_A_Id]
GO
ALTER TABLE [dbo].[ADictOil]  WITH CHECK ADD  CONSTRAINT [FK_dbo.ADictOil_dbo.ADictOil_DictOilId] FOREIGN KEY([DictOilId])
REFERENCES [dbo].[DictOil] ([Id])
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[ADictOil] CHECK CONSTRAINT [FK_dbo.ADictOil_dbo.ADictOil_DictOilId]
GO
-- DictOil
CREATE TABLE [dbo].[DictOil](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[Name] [nvarchar](100) NULL,
 CONSTRAINT [PK_dbo.DictOil] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO