PHP/MySQL: Select locations close to a given location from DB

Question

In PHP, I have the following code for calculating the distance between two locations:

Answer 1

Maybe something like

SELECT field1, field2, ...,
    ACOS(SIN(latitude / 180 * PI()) * SIN(:1) + COS(latitude / 180 * PI()) * COS(:2) * COS(:2 - longtidude)) * 6371 AS distance
    ORDER BY distance ASC;

or

SELECT field1, field2, ...,
    ACOS(SIN(RADIANS(latitude)) * SIN(:1) + COS(RADIANS(latitude)) * COS(:2) * COS(:2 - longtidude)) * 6371 AS distance
    ORDER BY distance ASC;

(directly translated from the PHP code)

:1 and :2 is $lat2/180*pi() and $long2/180*pi() respectively.