Question

I have a class and inside it, a string and a list of enumerators.

public enum SomeEnum
{
    Undefined=0,
    Enum1,
    Enum2,
    Enum3,
    End
}
public class SomeObject
{
    public virtual int ID{get; set;}
    public virtual String Name {get; set;}
    public virtual IList<SomeEnum> EnumList {get; set;}
}

Now, there should be a list of SomeObjects, containing ID and Name. There should be another map like this:

5 2
5 3
3 1
9 3

Meaning, a player with ID 5 has Enum2 and Enum3, another player with ID 3 has Enum1, and a player with ID 9 has Enum3.
They say it’s possible to map int, float etc. but I don’t want to create IList out of my list.

Is there an easy way to make fluent nhibernate do that?

HasMany(x => x.EnumList )
    .Cascade.All()
    .Table("ObjectEnumTable");

This mapping file throws an exception and says “Association references unmapped class: SomeEnum”.

Thanks in advance.

Answer 1

You’re better off storing your List of enum values as a straight Flags enum value, but if you absolutely must have a list of enums (you need support for duplicates or legacy database), then your mapping shoud look like this:

HasMany(x => x.EnumList )
    .Cascade.All()
    .Table("ObjectEnumTable")
    .Element("EnumValueColumn");

The key is the .Element() method which you must have for any non-entity HasMany relationship, including strings, ints, etc. This will give you the ID column referencing your parent entity, and an EnumValueColumn column with your enum value for each item.