--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/UnitTests/Linq/TakeSkipTest.cs	Thu Mar 27 21:46:09 2014 +0400
@@ -0,0 +1,324 @@
+using System;
+using System.Linq;
+
+using NUnit.Framework;
+
+using BLToolkit.Data.DataProvider;
+using BLToolkit.Data.Linq;
+
+namespace Data.Linq
+{
+	using Model;
+
+	[TestFixture]
+	public class TakeSkipTest : TestBase
+	{
+		[Test]
+		public void Take1()
+		{
+			ForEachProvider(db =>
+			{
+				for (var i = 2; i <= 3; i++)
+					Assert.AreEqual(i, (from ch in db.Child select ch).Take(i).ToList().Count);
+			});
+		}
+
+		static void TakeParam(ITestDataContext db, int n)
+		{
+			Assert.AreEqual(n, (from ch in db.Child select ch).Take(n).ToList().Count);
+		}
+
+		[Test]
+		public void Take2()
+		{
+			ForEachProvider(db => TakeParam(db, 1));
+		}
+
+		[Test]
+		public void Take3()
+		{
+			ForEachProvider(db =>
+				Assert.AreEqual(3, (from ch in db.Child where ch.ChildID > 3 || ch.ChildID < 4 select ch).Take(3).ToList().Count));
+		}
+
+		[Test]
+		public void Take4()
+		{
+			ForEachProvider(db =>
+				Assert.AreEqual(3, (from ch in db.Child where ch.ChildID >= 0 && ch.ChildID <= 100 select ch).Take(3).ToList().Count));
+		}
+
+		[Test]
+		public void Take5()
+		{
+			ForEachProvider(db => Assert.AreEqual(3, db.Child.Take(3).ToList().Count));
+		}
+
+		[Test]
+		public void Take6()
+		{
+			var expected = Child.OrderBy(c => c.ChildID).Take(3);
+
+			ForEachProvider(db =>
+			{
+				var result = db.Child.OrderBy(c => c.ChildID).Take(3);
+				Assert.IsTrue(result.ToList().SequenceEqual(expected));
+			});
+		}
+
+		[Test]
+		public void Take7()
+		{
+			ForEachProvider(db => Assert.AreEqual(3, db.Child.Take(() => 3).ToList().Count));
+		}
+
+		[Test]
+		public void Take8()
+		{
+			var n = 3;
+			ForEachProvider(db => Assert.AreEqual(3, db.Child.Take(() => n).ToList().Count));
+		}
+
+		[Test]
+		public void TakeCount()
+		{
+			ForEachProvider(new[] { ProviderName.Sybase }, db => Assert.AreEqual(
+				   Child.Take(5).Count(),
+				db.Child.Take(5).Count()));
+		}
+
+		[Test]
+		public void Skip1()
+		{
+			ForEachProvider(db => AreEqual(Child.Skip(3), db.Child.Skip(3)));
+		}
+
+		[Test]
+		public void Skip2()
+		{
+			var expected = (from ch in Child where ch.ChildID > 3 || ch.ChildID < 4 select ch).Skip(3);
+			ForEachProvider(db => AreEqual(expected, (from ch in db.Child where ch.ChildID > 3 || ch.ChildID < 4 select ch).Skip(3)));
+		}
+
+		[Test]
+		public void Skip3()
+		{
+			var expected = (from ch in Child where ch.ChildID >= 0 && ch.ChildID <= 100 select ch).Skip(3);
+			ForEachProvider(db => AreEqual(expected, (from ch in db.Child where ch.ChildID >= 0 && ch.ChildID <= 100 select ch).Skip(3)));
+		}
+
+		[Test]
+		public void Skip4()
+		{
+			var expected = Child.OrderByDescending(c => c.ChildID).Skip(3);
+
+			ForEachProvider(db =>
+			{
+				var result = db.Child.OrderByDescending(c => c.ChildID).Skip(3);
+				Assert.IsTrue(result.ToList().SequenceEqual(expected));
+			});
+		}
+
+		[Test]
+		public void Skip5()
+		{
+			var expected = Child.OrderByDescending(c => c.ChildID).ThenBy(c => c.ParentID + 1).Skip(3);
+			ForEachProvider(db => AreEqual(expected, db.Child.OrderByDescending(c => c.ChildID).ThenBy(c => c.ParentID + 1).Skip(3)));
+		}
+
+		[Test]
+		public void Skip6()
+		{
+			ForEachProvider(db => AreEqual(Child.Skip(3), db.Child.Skip(() => 3)));
+		}
+
+		[Test]
+		public void Skip7()
+		{
+			var n = 3;
+			ForEachProvider(db => AreEqual(Child.Skip(n), db.Child.Skip(() => n)));
+		}
+
+		[Test]
+		public void SkipCount()
+		{
+			ForEachProvider(new[] { "Sql2000", ProviderName.Sybase, ProviderName.SQLite, ProviderName.Access }, db => Assert.AreEqual(
+				   Child.Skip(2).Count(),
+				db.Child.Skip(2).Count()));
+		}
+
+		[Test]
+		public void SkipTake1()
+		{
+			var expected = Child.OrderByDescending(c => c.ChildID).Skip(2).Take(5);
+			ForEachProvider(db =>
+			{
+				var result = db.Child.OrderByDescending(c => c.ChildID).Skip(2).Take(5);
+				Assert.IsTrue(result.ToList().SequenceEqual(expected));
+			});
+		}
+
+		[Test]
+		public void SkipTake2()
+		{
+			var expected = Child.OrderByDescending(c => c.ChildID).Take(7).Skip(2);
+			ForEachProvider(db =>
+			{
+				var result = db.Child.OrderByDescending(c => c.ChildID).Take(7).Skip(2);
+				Assert.IsTrue(result.ToList().SequenceEqual(expected));
+			});
+		}
+
+		[Test]
+		public void SkipTake3()
+		{
+			var expected = Child.OrderBy(c => c.ChildID).Skip(1).Take(7).Skip(2);
+			ForEachProvider(db =>
+			{
+				var result = db.Child.OrderBy(c => c.ChildID).Skip(1).Take(7).Skip(2);
+				Assert.IsTrue(result.ToList().SequenceEqual(expected));
+			});
+		}
+
+		[Test]
+		public void SkipTake4()
+		{
+			var expected = Child.OrderByDescending(c => c.ChildID).Skip(1).Take(7).OrderBy(c => c.ChildID).Skip(2);
+			ForEachProvider(new[] { "Sql2000", ProviderName.SQLite, ProviderName.Sybase, ProviderName.Access }, db =>
+			{
+				var result = db.Child.OrderByDescending(c => c.ChildID).Skip(1).Take(7).OrderBy(c => c.ChildID).Skip(2);
+				Assert.IsTrue(result.ToList().SequenceEqual(expected));
+			});
+		}
+
+		[Test]
+		public void SkipTake5()
+		{
+			ForEachProvider(db =>
+			{
+				var list = db.Child.Skip(2).Take(5).ToList();
+				Assert.AreEqual(5, list.Count);
+			});
+		}
+
+		void SkipTake6(ITestDataContext db, bool doSkip)
+		{
+			var q1 = from g in db.GrandChild select g;
+
+			if (doSkip)
+				q1 = q1.Skip(12);
+			q1 = q1.Take(3);
+
+			var q2 =
+				from c in db.Child
+				from p in q1
+				where c.ParentID == p.ParentID
+				select c;
+
+			var q3 = from g in GrandChild select g;
+
+			if (doSkip)
+				q3 = q3.Skip(12);
+			q3 = q3.Take(3);
+
+			var q4 =
+				from c in Child
+				from p in q3
+				where c.ParentID == p.ParentID
+				select c;
+
+			AreEqual(q4, q2);
+		}
+
+		[Test]
+		public void SkipTake6()
+		{
+			ForEachProvider(
+				new[] { "Sql2000", ProviderName.SqlCe, ProviderName.SQLite, ProviderName.Access, ProviderName.Sybase },
+				db =>
+				{
+					SkipTake6(db, false);
+					SkipTake6(db, true);
+				});
+		}
+
+		[Test]
+		public void SkipTakeCount()
+		{
+			ForEachProvider(new[] { "Sql2000", ProviderName.SqlCe, ProviderName.Sybase, ProviderName.SQLite, ProviderName.Access }, db => Assert.AreEqual(
+				   Child.Skip(2).Take(5).Count(),
+				db.Child.Skip(2).Take(5).Count()));
+		}
+
+		[Test]
+		public void SkipFirst()
+		{
+			var expected = (from p in Parent where p.ParentID > 1 select p).Skip(1).First();
+
+			ForEachProvider(db =>
+			{
+				var result = from p in db.GetTable<Parent>() select p;
+				result = from p in result where p.ParentID > 1 select p;
+				var b = result.Skip(1).First();
+
+				Assert.AreEqual(expected, b);
+			});
+		}
+
+		[Test]
+		public void ElementAt1([DataContexts] string context)
+		{
+			using (var db = GetDataContext(context))
+				Assert.AreEqual(
+					(from p in    Parent where p.ParentID > 1 select p).ElementAt(3),
+					(from p in db.Parent where p.ParentID > 1 select p).ElementAt(3));
+		}
+
+		[Test]
+		public void ElementAt2()
+		{
+			var n = 3;
+			ForEachProvider(db => Assert.AreEqual(
+				(from p in    Parent where p.ParentID > 1 select p).ElementAt(n),
+				(from p in db.Parent where p.ParentID > 1 select p).ElementAt(() => n)));
+		}
+
+		[Test]
+		public void ElementAtDefault1()
+		{
+			ForEachProvider(db => Assert.AreEqual(
+				(from p in    Parent where p.ParentID > 1 select p).ElementAtOrDefault(3),
+				(from p in db.Parent where p.ParentID > 1 select p).ElementAtOrDefault(3)));
+		}
+
+		[Test]
+		public void ElementAtDefault2()
+		{
+			ForEachProvider(db => Assert.IsNull((from p in db.Parent where p.ParentID > 1 select p).ElementAtOrDefault(300000)));
+		}
+
+		[Test]
+		public void ElementAtDefault3()
+		{
+			var n = 3;
+			ForEachProvider(db => Assert.AreEqual(
+				(from p in    Parent where p.ParentID > 1 select p).ElementAtOrDefault(n),
+				(from p in db.Parent where p.ParentID > 1 select p).ElementAtOrDefault(() => n)));
+		}
+
+		[Test]
+		public void ElementAtDefault4()
+		{
+			var n = 300000;
+			ForEachProvider(db => Assert.IsNull((from p in db.Parent where p.ParentID > 1 select p).ElementAtOrDefault(() => n)));
+		}
+
+		[Test]
+		public void ElementAtDefault5()
+		{
+			ForEachProvider(db => Assert.AreEqual(
+				   Person.ElementAtOrDefault(3),
+				db.Person.ElementAtOrDefault(3)));
+		}
+	}
+}