Adding to/from GeoJSON Conversions to Sequel Queries

README.md

SQL for INSERT:

INSERT INTO geographies (type, name, geometry)
VALUES (
  'Location',
  'Vintage Heart Coffee',
  ST_GeomFromGeoJSON('{"type": "Point", "coordinates": [30.2642, -97.7277]}')
);
-- INSERT 0 1

SQL for SELECT:

SELECT name, ST_AsGeoJSON(geometry) as geo from geographies;
--          name         |                        geo                        
-- ----------------------+---------------------------------------------------
--  Vintage Heart Coffee | {"type":"Point","coordinates":[30.2642,-97.7277]}
-- (1 row)

extensions-geojson.rb

require 'delegate'

module Sequel

  module GeoJSON

    class GeoJSONGeometry < DelegateClass(Hash)
      def sql_literal_append(ds, sql)
        ds.literal_append(sql, Sequel.function(:ST_GeomFromGeoJSON, self))
      end
    end

    module DatabaseMethods
      def self.extended(db)
        db.instance_eval do
          add_named_conversion_procs(conversion_procs, :geometry => PG_NAMED_TYPES[:geometry])
          @schema_type_classes[:geometry] = [GeoJSONGeometry]
        end
      end

      

    end

    PG_NAMED_TYPES = {} unless defined?(PG_NAMED_TYPES)
    # Associate the named types by default.
    PG_NAMED_TYPES[:geometry] = JSON.method(:parse)
  end

  Database.register_extension(:geojson, GeoJSON::DatabaseMethods)
end