Search a Geographic Point

You can search a geographical point:

  • in ELLQL, in the search-api.

  • in UQL, using the geo: prefix handler.

You can search for a point by radius or within a polygon.

This task shows you how to:

See Also
About Geographic Points
Create a Geographic Point
Calculate Distances in Virtual Fields
NETVIBES Low-Level Query Language (ELLQL)

Search within a Radius (ELLQL)

  1. To get all the points around a certain point: 

    #distance(point_field, lat/x, long/y, distanceInMeters)
    .

  2. To also retrieve the distance of each point from the center: 

    #distance{name=pointQuery}(point_field, lat/x, long/y, distanceInMeters)

  3. Then use @pointQuery.distance in a virtual field.

Search within a Polygon (ELLQL)

To get all the points within a polygon: 

#within(point_field, (X1, Y1; X2, Y2; X3, Y3; ...))

where Xn Yn are corners of your polygon in the same coordinate format as your points.

For example:

#within(gps, (0.0, 0.0; 1.0,0.0; 1.0,1.0; 0.0, 1.0))

Returns all the points within the square (0.0, 0.0) - (1.0, 1.0).

#within(gps, [(0.0, 0.0; 2.0, 0.0; 2.0, 2.0; 0.0, 2.0) (1.0, 1.0; 3.0, 1.0; 3.0, 3.0; 1.0, 3.0)]

Returns all the points within the square (0.0, 0.0) - (2.0, 2.0) OR (1.0, 1.0) - (3.0, 3.0) but not in both.

Search with a Radius or Polygon (UQL)

In UQl, you can use the following operands with a Geographic prefix handler (geo:).

Operand

Example

within(lat1,lng1; lat2, lng2; lat3, lng3;)

searches all the locations within the specified polygon

geo:WITHIN(48.33, 2.51; 45.65, 1.34; 24.54, -4.54; 12.34, -6.65)

distance(lat, lng, distance_in_meters)

retrieves all the documents where the geographic field is located distance_in_meters from the specified lat, lng

geo:DISTANCE(48.33, 2.51, 250000)