IdentifierCollection.cs

using System;
using NHibernate.Engine;

namespace NHibernate.Mapping
{
	/// <summary>
	/// A collection with a synthetic "identifier" column.
	/// </summary>
	[Serializable]
	public abstract class IdentifierCollection : Collection
	{
		public const string DefaultIdentifierColumnName = "id";
		private IKeyValue identifier;

		/// <summary>
		/// 
		/// </summary>
		/// <param name="owner"></param>
		protected IdentifierCollection(PersistentClass owner) : base(owner)
		{
		}

		/// <summary></summary>
		public IKeyValue Identifier
		{
			get { return identifier; }
			set { identifier = value; }
		}

		/// <summary></summary>
		public override bool IsIdentified
		{
			get { return true; }
		}

		/// <summary></summary>
		public override void CreatePrimaryKey()
		{
			if (!IsOneToMany)
			{
				PrimaryKey pk = new PrimaryKey();
				pk.AddColumns(Identifier.ColumnIterator);
				CollectionTable.PrimaryKey = pk;
			}
			//else // Create an index on the key columns?
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="mapping"></param>
		public override void Validate(IMapping mapping)
		{
			base.Validate(mapping);
			if (!Identifier.IsValid(mapping))
			{
				throw new MappingException(
					string.Format("collection id mapping has wrong number of columns: {0} type: {1}", Role, Identifier.Type.Name));
			}
		}
	}
}