How should I store a user's height and weight in a MySQL database such that I can use the information to find users within a certain height or weight? Also, I will need to be able to display this information in either English or metric system.
My idea is to store the information for height in centimeters and weight in kilograms (I prefer metric over English). I can even let the user enter their information and English system, but do the conversion to metric before saving. I think converting kilograms to pounds might be easy to do in SQL, but I'm not sure how easy it would be to convert 178 centimeters to 5'10" (rounded slightly down).
Should I be saving English and metric values in the database so that I don't need to do conversions when I do my queries? Sounds like a bad idea to store derived/computed values.