/UnitTests/Linq/Distinct.cs

using System;

using System.Linq;



using NUnit.Framework;



using BLToolkit.Data.DataProvider;



namespace Data.Linq

{

	using Model;



	[TestFixture]

	public class DistinctTest : TestBase

	{

		[Test]

		public void Distinct1()

		{

			ForEachProvider(db => AreEqual(

				(from ch in    Child select ch.ParentID).Distinct(),

				(from ch in db.Child select ch.ParentID).Distinct()));

		}



		[Test]

		public void Distinct2()

		{

			ForEachProvider(db => AreEqual(

				(from p in    Parent select p.Value1 ?? p.ParentID % 2).Distinct(),

				(from p in db.Parent select p.Value1 ?? p.ParentID % 2).Distinct()));

		}



		[Test]

		public void Distinct3()

		{

			ForEachProvider(db => AreEqual(

				(from p in    Parent select new { Value = p.Value1 ?? p.ParentID % 2, p.Value1 }).Distinct(),

				(from p in db.Parent select new { Value = p.Value1 ?? p.ParentID % 2, p.Value1 }).Distinct()));

		}



		[Test]

		public void Distinct4()

		{

			ForEachProvider(db => AreEqual(

				(from p in    Parent select new Parent { ParentID = p.Value1 ?? p.ParentID % 2, Value1 = p.Value1 }).Distinct(),

				(from p in db.Parent select new Parent { ParentID = p.Value1 ?? p.ParentID % 2, Value1 = p.Value1 }).Distinct()));

		}



		[Test]

		public void Distinct5()

		{

			var id = 2;



			ForEachProvider(db => AreEqual(

				(from p in    Parent select new Parent { ParentID = p.Value1 ?? p.ParentID % 2, Value1 = id + 1 }).Distinct(),

				(from p in db.Parent select new Parent { ParentID = p.Value1 ?? p.ParentID % 2, Value1 = id + 1 }).Distinct()));

		}



		[Test]

		public void Distinct6()

		{

			var id = 2;



			ForEachProvider(new[] { ProviderName.Informix }, db => AreEqual(

				(from p in    Parent select new Parent { ParentID = p.Value1 ?? p.ParentID + id % 2, Value1 = id + 1 }).Distinct(),

				(from p in db.Parent select new Parent { ParentID = p.Value1 ?? p.ParentID + id % 2, Value1 = id + 1 }).Distinct()));

		}



		[Test]

		public void DistinctCount()

		{

			var expected =

				from p in Parent

					join c in Child on p.ParentID equals c.ParentID

				where c.ChildID > 20

				select p;



			ForEachProvider(db =>

			{

				var result =

					from p in db.Parent

						join c in db.Child on p.ParentID equals c.ParentID

					where c.ChildID > 20

					select p;



				Assert.AreEqual(expected.Distinct().Count(), result.Distinct().Count());

			});

		}



		[Test]

		public void DistinctMax()

		{

			var expected =

				from p in Parent

					join c in Child on p.ParentID equals c.ParentID

				where c.ChildID > 20

				select p;



			ForEachProvider(db =>

			{

				var result =

					from p in db.Parent

						join c in db.Child on p.ParentID equals c.ParentID

					where c.ChildID > 20

					select p;



				Assert.AreEqual(expected.Distinct().Max(p => p.ParentID), result.Distinct().Max(p => p.ParentID));

			});

		}



		[Test]

		public void TakeDistinct()

		{

			ForEachProvider(new[] { ProviderName.Sybase, ProviderName.SQLite },

				db => AreEqual(

					(from ch in    Child orderby ch.ParentID select ch.ParentID).Take(4).Distinct(),

					(from ch in db.Child orderby ch.ParentID select ch.ParentID).Take(4).Distinct()));

		}

	}

}