Getting Distance with Azure Search Service

Question

I have an object such as this:

[SerializePropertyNamesAsCamelCase]
public class Location
{
    [Key]
    public string Id { get; set; }

    [IsFilterable, IsSortable]
    public GeographyPoint GeographyPoint { get; set; }
}

What I would like to do is retrieve all locations that are within 10 KM and order them by distance, so closest show first. Lastly, I want to know what that distance is.

Here is what I tried:

var index = GetIndex();

var parameters = new SearchParameters
{
    Skip = 0,
    Top = 20,
    Filter = "geo.distance(geographyPoint, geography'POINT(-122.131577 47.678581)') le 10  "
};

var results = index.Documents.Search<Location>("*", parameters);

The problem with above is that it doesn't tell me the distance, nor does it sort by it.

I'm wondering how to accomplish the above? Do I have to create a double Distance property inside Location object and if so, then how do I populate it so I can search by it, order by it and then retrieve it?

Possible duplicate of [Return Value from geo.distance function in a select query](https://stackoverflow.com/questions/51484560/return-value-from-geo-distance-function-in-a-select-query) — Bruce Johnston, Sep 17 '18 at 16:28

score 3 · Answer 1 · answered Aug 10 '19 at 14:49

var orderBy = new List<string>();
orderBy.Add("geo.distance(LatLong, geography'POINT(" + request.LatLong + ")')");

var parameters = new SearchParameters {
Skip = 0,
Top = 20,
Filter = "geo.distance(geographyPoint, geography'POINT(-122.131577 47.678581)') le 10",
OrderBy = orderBy };

You can also add asc/desc to the end of your order by variable to return results ascending or descending.

Unfortunately azure search doesn't return the distance, you will have to calculate that yourself.

Getting Distance with Azure Search Service

1 Answers1