--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HowTo/Data/ComplexMapping.cs	Thu Mar 27 21:46:09 2014 +0400
@@ -0,0 +1,216 @@
+using System;
+using System.Collections.Generic;
+
+using NUnit.Framework;
+
+using BLToolkit.Mapping;
+using BLToolkit.Data;
+using BLToolkit.DataAccess;
+using BLToolkit.Reflection.Extension;
+
+namespace HowTo.Data
+{
+	[TestFixture]
+	public class ComplexMapping
+	{
+		const string TestQuery = @"
+			-- Parent Data
+			SELECT       1 as ParentID
+			UNION SELECT 2 as ParentID
+
+			-- Child Data
+			SELECT       4 ChildID, 1 as ParentID
+			UNION SELECT 5 ChildID, 2 as ParentID
+			UNION SELECT 6 ChildID, 2 as ParentID
+			UNION SELECT 7 ChildID, 1 as ParentID
+
+			-- Grandchild Data
+			SELECT       1 GrandchildID, 4 as ChildID
+			UNION SELECT 2 GrandchildID, 4 as ChildID
+			UNION SELECT 3 GrandchildID, 5 as ChildID
+			UNION SELECT 4 GrandchildID, 5 as ChildID
+			UNION SELECT 5 GrandchildID, 6 as ChildID
+			UNION SELECT 6 GrandchildID, 6 as ChildID
+			UNION SELECT 7 GrandchildID, 7 as ChildID
+			UNION SELECT 8 GrandchildID, 7 as ChildID
+";
+
+		public class Parent
+		{
+			[MapField("ParentID"), /*[a]*/PrimaryKey/*[/a]*/]
+			public int ID;
+
+			/*[a]*/[Relation(typeof(Child))]/*[/a]*/
+			public List<Child> Children = new List<Child>();
+		}
+
+		[MapField("ParentID", "Parent.ID")]
+		public class Child
+		{
+			[MapField("ChildID"), /*[a]*/PrimaryKey/*[/a]*/]
+			public int ID;
+
+			/*[a]*/[Relation]/*[/a]*/
+			public Parent Parent = new Parent();
+
+			/*[a]*/[Relation(typeof(Grandchild))]/*[/a]*/
+			public List<Grandchild> Grandchildren = new List<Grandchild>();
+		}
+
+		[MapField("ChildID", "Child.ID")]
+		public class Grandchild
+		{
+			[MapField("GrandchildID"), /*[a]*/PrimaryKey/*[/a]*/]
+			public int ID;
+
+			/*[a]*/[Relation]/*[/a]*/
+			public Child Child = new Child();
+		}
+
+		[Test]
+		public void Test()
+		{
+			List<Parent>   parents = new List<Parent>();
+			/*[a]*/MapResultSet/*[/a]*/[] sets    = new MapResultSet[3];
+
+			sets[0] = new MapResultSet(typeof(Parent), parents);
+			sets[1] = new MapResultSet(typeof(Child));
+			sets[2] = new MapResultSet(typeof(Grandchild));
+
+			sets[0].AddRelation(sets[1], "ParentID", "ParentID", "Children");
+			sets[1].AddRelation(sets[0], "ParentID", "ParentID", "Parent");
+
+			sets[1].AddRelation(sets[2], "ChildID", "ChildID", "Grandchildren");
+			sets[2].AddRelation(sets[1], "ChildID", "ChildID", "Child");
+
+			using (DbManager db = new DbManager())
+			{
+				db
+					.SetCommand      (TestQuery)
+					./*[a]*/ExecuteResultSet/*[/a]*/(sets);
+			}
+
+			Assert.IsNotEmpty(parents);
+
+			foreach (Parent parent in parents)
+			{
+				Assert.IsNotNull(parent);
+				Assert.IsNotEmpty(parent.Children);
+
+				foreach (Child child in parent.Children)
+				{
+					Assert.AreEqual(parent, child.Parent);
+					Assert.IsNotEmpty(child.Grandchildren);
+
+					foreach (Grandchild grandchild in child.Grandchildren)
+					{
+						Assert.AreEqual(child,  grandchild.Child);
+						Assert.AreEqual(parent, grandchild.Child.Parent);
+					}
+				}
+			}
+		}
+		
+		[Test]
+		public void Test2()
+		{
+			List<Parent> parents = new List<Parent>();
+			/*[a]*/MapResultSet/*[/a]*/[] sets = new MapResultSet[3];
+
+			sets[0] = new MapResultSet(typeof(Parent), parents);
+			sets[1] = new MapResultSet(typeof(Child));
+			sets[2] = new MapResultSet(typeof(Grandchild));
+
+			using (DbManager db = new DbManager())
+			{
+				db
+					.SetCommand(TestQuery)
+					./*[a]*/ExecuteResultSet/*[/a]*/(sets);
+			}
+
+			Assert.IsNotEmpty(parents);
+
+			foreach (Parent parent in parents)
+			{
+				Assert.IsNotNull(parent);
+				Assert.IsNotEmpty(parent.Children);
+
+				foreach (Child child in parent.Children)
+				{
+					Assert.AreEqual(parent, child.Parent);
+					Assert.IsNotEmpty(child.Grandchildren);
+
+					foreach (Grandchild grandchild in child.Grandchildren)
+					{
+						Assert.AreEqual(child, grandchild.Child);
+						Assert.AreEqual(parent, grandchild.Child.Parent);
+					}
+				}
+			}
+		}
+
+		public class ParentEx
+		{
+			public int           ID;
+			public List<ChildEx> Children = new List<ChildEx>();
+		}
+
+		public class ChildEx
+		{
+			public int                ID;
+			public ParentEx           Parent        = new ParentEx();
+			public List<GrandchildEx> Grandchildren = new List<GrandchildEx>();
+		}
+
+		public class GrandchildEx
+		{
+			public int     ID;
+			public ChildEx Child = new ChildEx();
+		}
+
+		static readonly MappingSchema _mappingSchema = new MappingSchema
+		{
+			Extensions = TypeExtension.GetExtensions("RelationExtension.xml")
+		};
+
+		[Test]
+		public void Test3()
+		{
+			var parents = new List<ParentEx>();
+			var sets    = new /*[a]*/MapResultSet/*[/a]*/[3];
+
+			sets[0] = new MapResultSet(typeof(ParentEx), parents);
+			sets[1] = new MapResultSet(typeof(ChildEx));
+			sets[2] = new MapResultSet(typeof(GrandchildEx));
+
+			using (var db = new DbManager())
+			{
+				db.MappingSchema = _mappingSchema;
+
+				db
+					.SetCommand(TestQuery)
+					./*[a]*/ExecuteResultSet/*[/a]*/(sets);
+			}
+
+			Assert.IsNotEmpty(parents);
+
+			foreach (ParentEx parent in parents)
+			{
+				Assert.IsNotNull(parent);
+				Assert.IsNotEmpty(parent.Children);
+
+				foreach (ChildEx child in parent.Children)
+				{
+					Assert.AreEqual(parent, child.Parent);
+					Assert.IsNotEmpty(child.Grandchildren);
+
+					foreach (GrandchildEx grandchild in child.Grandchildren)
+					{
+						Assert.AreEqual(child, grandchild.Child);
+						Assert.AreEqual(parent, grandchild.Child.Parent);
+					}
+				}
+			}
+		}
+	}
+}