Querying: Intersection

To allow users to Intersect queries on the server-side and return only documents that match all the provided sub-queries, we introduced the query intersection feature.
In this page:
- Intersection

Intersection

Let's 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; }
}

We will fill our database with a 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 need to do the following:

add the Raven.Client.Documents namespace to usings
use the Intersect query extension:

Query
DocumentQuery
Index
RQL

IList<TShirt> results = session.Query<TShirts_ByManufacturerColorSizeAndReleaseYear.Result, TShirts_ByManufacturerColorSizeAndReleaseYear>()
     .Where(x => x.Manufacturer == "Raven")
     .Intersect()
     .Where(x => x.Color == "Blue" && x.Size == "Small")
     .Intersect()
     .Where(x => x.Color == "Gray" && x.Size == "Large")
     .OfType<TShirt>()
     .ToList();

IList<TShirt> results = session
  .Advanced
  .DocumentQuery<TShirt, TShirts_ByManufacturerColorSizeAndReleaseYear>()
  .WhereEquals("Manufacturer", "Raven")
  .Intersect()
  .WhereEquals("Color", "Blue")
  .AndAlso()
  .WhereEquals("Size", "Small")
  .Intersect()
  .WhereEquals("Color", "Gray")
  .AndAlso()
  .WhereEquals("Size", "Large")
  .ToList();

public class TShirts_ByManufacturerColorSizeAndReleaseYear : AbstractIndexCreationTask<TShirt>
{
  public class Result
  {
      public string Manufacturer { get; set; }

      public string Color { get; set; }

      public string Size { get; set; }

      public int ReleaseYear { get; set; }
  }

  public TShirts_ByManufacturerColorSizeAndReleaseYear()
  {
      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
                       };
  }
}

from index 'TShirts/ByManufacturerColorSizeAndReleaseYear' 
where intersect(Manufacturer = 'Raven', Color = 'Blue' and Size = 'Small', Color = 'Gray' and Size = 'Large')

The above query will return tshirts/1 and tshirts/4, that match all sub-queries.
tshirts/2 will not be included in the results because it is not manufactured by Raven, and tshirts/3 will not be included because it is not available in Small Blue.

Intersection​

Intersection