adrienne

/**
 * Generates the string for the Haversine function. We assume that the `zipcode`, `latitude`,
 * and `longitude` columns are named accordingly. We are also not doing much error-checking
 * here; this is a simple text cruncher to make things prettier.
 * We may also be integrating some extra SQL in, passed in via the $extra parameter
 * 
 * @param   string      $table      The table to search in
 * @param   float       $lat        The latitude part of the reference coordinates
 * @param   float       $lng        The longitude part of the reference coordinates
 * @param   int         $radius     The radius to search within