Storing decimal number with MySQL

Question

What's the best type to store values such:

48.89384 and -2.34910

Actually I'm using float.

Answer 1

Use decimal for exact values.

Notes:

• ABS (Latitude) <= 90
• ABS (Longitude) <= 180

So you can us 2 different types

• Latitude = decimal (x+2, x)
• Longitude = decimal (y+3, y)

x and y will be the desired precision. Given a metre is 1/40,000,000 of the earth's circumferemce, something like 6-8 will be enough depending on whether you're going for street or full stop accuracy in location.