IdentifierProjection.cs

using System;
using NHibernate.Persister.Entity;
using NHibernate.SqlCommand;
using NHibernate.Type;

namespace NHibernate.Criterion
{
	[Serializable]
	public class IdentifierProjection : SimpleProjection, IPropertyProjection
	{
		private bool grouped;

		protected internal IdentifierProjection(bool grouped)
		{
			this.grouped = grouped;
		}

		protected internal IdentifierProjection() : this(false)
		{
		}

		public override string ToString()
		{
			return PropertyName;
		}

		public override IType[] GetTypes(ICriteria criteria, ICriteriaQuery criteriaQuery)
		{
			return new IType[] {criteriaQuery.GetIdentifierType(criteria)};
		}

		public override SqlString ToSqlString(ICriteria criteria, int position, ICriteriaQuery criteriaQuery)
		{
			SqlStringBuilder buf = new SqlStringBuilder();
			string[] cols = criteriaQuery.GetIdentifierColumns(criteria);
			for (int i = 0; i < cols.Length; i++)
			{
				if (i > 0)
				{
					buf.Add(", ");
				}

				buf.Add(cols[i])
					.Add(" as y")
					.Add((position + i).ToString())
					.Add("_");
			}
			return buf.ToSqlString();
		}

		public override bool IsGrouped
		{
			get { return grouped; }
		}

		public override bool IsAggregate
		{
			get { return false; }
		}

		public override SqlString ToGroupSqlString(ICriteria criteria, ICriteriaQuery criteriaQuery)
		{
			if (!grouped)
			{
				throw new InvalidOperationException("not a grouping projection");
			}
			return new SqlString(string.Join(",", criteriaQuery.GetIdentifierColumns(criteria)));
		}

		public string PropertyName => EntityPersister.EntityID;
	}
}