Mapping a a simple collection of elements with Fluent NHibernate - fluent-nhibernate

Question

I'm trying to map a collection of enum values with Fluent NHibernate.
IList<EnumType> lst;
I can't find any documentation about it but I'm quite sure it should be possible.
I had no problem at all with mapping a collection of Entities.
Thanks,
Leonardo

Answer 1

You can use the following FNH mapping signature to map simple value type collections.
HasMany(x => x.Collection)
.Table("TableName")
.KeyColumn("KeyColumnName")
.Element("ValueColumnName");
Where:
Collection: the collection of value types (can be enum because that will be mapped as int).
TableName: the name of the table that will store your collection values.
KeyColumnName: the name of the column that will store the key value back to the parent.
ValueColumnName : the name of the column that will store the actual value.
Lets see an example of how to map a few collections of value types.
public enum EnumType
{
Value1,
Value2,
Value3
}
public class Entity
{
/// <summary>
/// Primary key
/// </summary>
public virtual int Id { get; set; }
/// <summary>
/// Collection of strings
/// </summary>
public virtual IList<string> StringCollection { get; set; }
/// <summary>
/// Collection of enums
/// </summary>
public virtual IList<EnumType> EnumCollection { get; set; }
/// <summary>
/// Collection of dates/times
/// </summary>
public virtual IList<DateTime> DateTimeCollection { get; set; }
}
public class EntityMap : ClassMap<Entity>
{
public EntityMap()
{
// Map primary key.
Id(x => x.Id);
// Map value collections
HasMany(x => x.StringCollection)
.Table("Entity_String")
.KeyColumn("EntityId")
.Element("String");
HasMany(x => x.EnumCollection)
.Table("Entity_Enum")
.KeyColumn("EntityId")
.Element("Enum");
HasMany(x => x.DateTimeCollection)
.Table("Entity_DateTime")
.KeyColumn("EntityId")
.Element("DateTime");
}
}
The result of this mapping will produce four (4) tables.
Table Entity with one column Id of int.
Table Entity_String with two columns - EntityId : int, String : varchar, and a foreign key EntityId to Entity table Id column.
... likewise, except column is of int type.
... likewise, except column is of datetime type.

Answer 2

HasMany(x => x.Items)
.Table("tbl")
.KeyColumn("fk")
.Element("eCol")
.AsBag()