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Intersection

To allow users to Intersect queries on the server-side and return only documents that match all the provided sub-queries we have introduced the query intersection feature.

Lets consider a case, where we have a T-Shirt class:

public class TShirt
{
	public string Id { get; set; }

	public int ReleaseYear { get; set; }

	public string Manufacturer { get; set; }

	public List<TShirtType> Types { get; set; }
}

public class TShirtType
{
	public string Color { get; set; }

	public string Size { get; set; }
}

Index:

public class TShirtIndex : AbstractIndexCreationTask<TShirt>
{
	public TShirtIndex()
	{
		this.Map = tshirts => from tshirt in tshirts
							  from type in tshirt.Types
							  select new
								  {
									  Manufacturer = tshirt.Manufacturer,
									  Color = type.Color,
									  Size = type.Size,
									  ReleaseYear = tshirt.ReleaseYear
								  };
	}
}

Few records:

session.Store(new TShirt
	{
		Id = "tshirts/1",
		Manufacturer = "Raven",
		ReleaseYear = 2010,
		Types = new List<TShirtType>
			{
				new TShirtType {Color = "Blue", Size = "Small"},
				new TShirtType {Color = "Black", Size = "Small"},
				new TShirtType {Color = "Black", Size = "Medium"},
				new TShirtType {Color = "Gray", Size = "Large"}
			}
	});

session.Store(new TShirt
{
	Id = "tshirts/2",
	Manufacturer = "Wolf",
	ReleaseYear = 2011,
	Types = new List<TShirtType>
			{
				new TShirtType { Color = "Blue",  Size = "Small" },                                    
				new TShirtType { Color = "Black", Size = "Large" },
				new TShirtType { Color = "Gray",  Size = "Medium" }
			}
});

session.Store(new TShirt
{
	Id = "tshirts/3",
	Manufacturer = "Raven",
	ReleaseYear = 2011,
	Types = new List<TShirtType>
			{
				new TShirtType { Color = "Yellow",  Size = "Small" },
				new TShirtType { Color = "Gray",  Size = "Large" }
			}
});

session.Store(new TShirt
{
	Id = "tshirts/4",
	Manufacturer = "Raven",
	ReleaseYear = 2012,
	Types = new List<TShirtType>
			{
				new TShirtType { Color = "Blue",  Size = "Small" },
				new TShirtType { Color = "Gray",  Size = "Large" }
			}
});

Now we want to return all the T-shirts that are manufactured by Raven and contain both Small Blue and Large Gray types. To do this, we just need to use Intersect query extension from Raven.Client namespace

session.Query<TShirt>("TShirtIndex")
	   .Where(x => x.Manufacturer == "Raven")
	   .Intersect()
	   .Where(x => x.Types.Any(t => t.Color == "Blue" && t.Size == "Small"))
	   .Intersect()
	   .Where(x => x.Types.Any(t => t.Color == "Gray" && t.Size == "Large"))
	   .ToList();

or its equivalent in Lucene syntax

session.Advanced.LuceneQuery<TShirt>("TShirtIndex")
	   .Where("Manufacturer:Raven INTERSECT Color:Blue AND Size:Small INTERSECT Color:Gray AND Size:Large")
	   .ToList();

Above query will return tshirts/1 and tshirts/4 as a result. Document tshirts/2 will not be included, because it is not manufactured by Raven and tshirts/3 is not available in Small Blue so it does not match all the sub-queries.