Postgres Sequel: GIS and Full Text

event.rb

#Find Nearest points in a radius in miles
def_dataset_method(:nearest) do |lat, lng, radius|
    radius = radius / 0.000621371
    where("ST_DWithin(geo_location, 'POINT(#{lng} #{lat})', #{radius})")
end

#To set the geo location for an event
def updateGeography()
    self.db.run("update events set geo_location = ST_GeographyFromText('POINT(#{self.lng} #{self.lat})') where id=#{self.id};")
end

Migration.rb

Sequel.migration do
  up do
	run("create extension if not exists postgis;")
	alter_table :events do
		add_column :geo_location, :geography
		add_full_text_index [:description, :name], :language=>'english'
		add_index :geo_location, :type=>:gist
	end
  end

  down do
	alter_table :events do
		drop_column :geo_location
		drop_index :geo_location
		drop_index [:description, :name]
	end
  end
end