Correct datatype for latitude and longitude? (in activerecord)

Question

Should I store latitude and longitude as strings or floats (or something else)?

(I'm using activerecord / ruby on rails, if that matters).

Update:

Mysql in development and postgresql in production (why does it matter?)

Answer 1

This is what I use:

add_column :table_name, :lat, :decimal, {:precision=>10, :scale=>6} add_column :table_name, :lng, :decimal, {:precision=>10, :scale=>6} 

Answer 2

If you need to do more complex geographical calculations, you can investigate PostGIS for Postgresql or MySQL Spatial Extensions for MySQL. Otherwise, a float (double precision might be a good idea) should work.

Edit: It looks like the GeoRuby library includes a Rails extension for working with the spatial/GIS extensions for both of the aforementioned databases.