CakePHP query closest latitude longitude from database

Question

In a CakePHP (v3) application, how can I retrieve the closest results based on passed lat lng values?

I'd like to have them back as native CakePHP entities, so something like this:

public function closest($lat, $lng) {

    $sightings = //records within given lat lng 

    $this->set(compact('sightings'));
    $this->set('_serialize', ['sightings']);
}

I know this SQL works:

SELECT *,
       ( 3959 * acos( cos( radians(50.7) ) * cos( radians( latitude ) ) * cos( radians( longitude ) - radians(-1.8) ) + sin( radians(50.7) ) * sin( radians( latitude ) ) ) ) AS distance
  FROM sightings
HAVING distance < 10
 ORDER BY distance
 LIMIT 0 , 20

Struggling to combine the two.

UPDATE

I've added

class Sighting extends Entity {
    public $_virtual = ['distance'];
    //rest of class...
}

So now the distance is showing up in my json output (with the value of null as would be expected right now, but I feel it's a step at lease).

I've taken a look here: http://www.mrthun.com/2014/11/26/search-distance-cakephp/ which seems to be what I'm trying to achieve so assumed something like this:

$latitude = 51.145;
$longitude = -1.45;
$distance = 100;

$this->Sightings->virtualFields
    = array('Sightings.distance'
     => '(3959 * acos (cos ( radians('.$latitude.') )
    * cos( radians( Sightings.latitude ) )
    * cos( radians( Sightings.longitude )
    - radians('.$longitude.') )
    + sin ( radians('.$latitude.') )
    * sin( radians( Sightings.latitude ) )))');

$sightings = $this->Sightings->find('all', [
    'conditions' => ['Sightings.distance <' => $distance]
]);

$this->set(compact('sightings'));
$this->set('_serialize', ['sightings']);

Results in: Column not found: 1054 Unknown column 'Sightings.distance' in 'where clause'

Not sure if it's possible CakePHP v2 as opposed to v3?

Answer 1

there are no more virtualFields in cake 3 but you still can create an alias for your calculated field

As suggested by @ndm you'd better bind $latitude and $longitude to prevent SQL injections

$distanceField = '(3959 * acos (cos ( radians(:latitude) )
    * cos( radians( Sightings.latitude ) )
    * cos( radians( Sightings.longitude )
    - radians(:longitude) )
    + sin ( radians(:latitude) )
    * sin( radians( Sightings.latitude ) )))';

using where

$sightings = $this->Sightings->find()
    ->select([
        'distance' => $distanceField
    ])
    ->where(["$distanceField < " => $distance])
    ->bind(':latitude', $latitude, 'float')
    ->bind(':longitude', $longitude, 'float')
    ->contain(['Photos', 'Tags']);

using having

$sightings = $this->Sightings->find()
    ->select([
        'distance' => $distanceField
    ])
    ->having(['distance < ' => $distance])
    ->bind(':latitude', $latitude, 'float')
    ->bind(':longitude', $longitude, 'float')
    ->contain(['Photos', 'Tags']);