mysql 经纬度计算

function location_sql($lng, $lat, $alias = 'distance')
{
    return "ROUND( 6371.393 * 2 * ASIN( SQRT( POW(  SIN(  (  {$lat} * 3.141592653 / 180 - lat * PI() / 180   ) / 2  ), 2  )  + COS( {$lat} * 3.141592653 / 180) * COS(lat * PI() / 180) * POW(  SIN( ( {$lng} * 3.141592653 / 180 - lng * PI() / 180  ) / 2 ),2  )  ) ) * 1000 ) AS {$alias}";
}

实例

  $lsql = location_sql($lng, $lat);
  $field = "id,avatar,lng,lat,star,store_id,created_at,{$lsql}";