Fluent NHibernate Mapping for Table in multiple HasMany Relationships

Question

What is wrong with my class mappings below?

public class Foo
{
    public Foo()
    {
        ActualCurve = new List<Point>();
        TargetCurve = new List<Point>();
    }
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
    public virtual IList<Point> ActualCurve { get; set; }
    public virtual IList<Point> TargetCurve { get; set; }
}

public class Point
{
    public virtual int Id { get; set; }
    public virtual double X { get; set; }
    public virtual double Y { get; set; }
}

public class FooMapping() : ClassMap<Foo>
{
    Table("Foos");
    Id(x => x.Id).GeneratedBy.Identity();
    Map(x => x.Name).Not.Nullable();
    HasMany(x => x.ActualCurve ).Cascade.All();
    HasMany(x => x.TargetCurve ).Cascade.All();
}

public class PointMapping() : ClassMap<Point>
{
    Table("Points");
    Not.LazyLoad();
    Id(x => x.Id).GeneratedBy.Identity();
    Map(x => x.X).Not.Nullable();
    Map(x => x.Y).Not.Nullable();
}

These mappings produce

CREATE TABLE [dbo].[Foos](
    [Id] [int] IDENTITY(1,1) NOT NULL,
    [Name] [nvarchar] NOT NULL,
    [RecipeRevisionId] [int] NOT NULL

CREATE TABLE [dbo].[Points](
    [Id] [int] IDENTITY(1,1) NOT NULL,
    [X] [float] NOT NULL,
    [Y] [float] NOT NULL,
    [FooId] [int] NOT NULL

Essentially, the problem is that when I am pulling a persisted Foo object back out of the database, the Foo.ActualCurve and Foo.TargetCurve lists both get populated with the combined contents of both lists. There clearly isn't a column that keys which set of points belong to the correct curve within Foo, but I am not sure how to change the mapping to maintain the two distinct sets of Points.

Isn't the point of Fluent that you don't have to mapping tables to classes. Why not use the built-in functionality? — Ash Burlaczenko

Jouni Aro Jouni Aro · Accepted Answer · 2012-05-18T21:52:53

I think you will need to specify a separate column for the references:

HasMany(x => x.ActualCurve ).Cascade.All().KeyColumn("ActualCurveId");
HasMany(x => x.TargetCurve ).Cascade.All().KeyColumn("TargetCurveId");

EDIT: Column->KeyColumn

Fluent NHibernate Mapping for Table in multiple HasMany Relationships

1 Answers