The correct data type for latitude and longitude? (in activerecord)

Question

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

(I use activerecord / ruby ​​on rails, if that matters).

Answer 1

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

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

Answer 2

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 3

If you don’t use a database with spatial support, Google Maps recommends using floats of size (10.6). This gives you 6 digits after the decimal number - if you want more precision, you can adjust accordingly.

Answer 4

I would suggest using a float, although in reality this is not so much different. Floats are easier to do if you ever want it in the future.

Answer 5

Typically, you want the Lat / Long to be stored in the largest float that you have. At some latitudes (for example, near the equator), very small changes in longitude can be equated to large differences in terms of surface distance.

I suppose if this is a field that you never want to do math, you can use a string. I would not have avoided this.

Answer 6

Since they are fixed precision, you must convert and save as an integer to significantly improve performance.

(SEE http://www.postgresql.org/docs/9.1/static/datatype-numeric.html#DATATYPE-NUMERIC-DECIMAL )