Haversine Query Scope

Model.php

<?php

class BaseModel {
    const UNIT_KM = 111.045;
    const UNIT_MI = 69.0;
    
    // Throw this function in any model with latitude/longitude columns
    // Or if multiple models have those values you can put it in your BaseModel
    public function scopeNearLatLong($query, $lat, $lng, $radius = 10, $unit = 69.0)
    {
        if (!is_numeric($lat) || -90 >= $lat || $lat >= 90) {
            throw new RangeException("Latitude must be between -90 and 90 degrees.");
        }

        if (!is_numeric($lng) || -180 >= $lng || $lng >= 180) {
            throw new RangeException("Longitude must be between -180 and 180 degrees.");
        }
        
        $subQuery = clone $query;
        
        $latDistance = $radius / $unit;
        $latNorth    = $lat - $latDistance;
        $latSouth    = $lat + $latDistance;
        
        $lngDistance = $radius / ($unit * cos(deg2rad($lat)));
        $lngEast     = $lng - $lngDistance;
        $lngWest     = $lng + $lngDistance;
        
        $subQuery->selectRaw(DB::raw('*, (? * DEGREES(
            ACOS(
                  COS(RADIANS(?)) * COS(RADIANS(latitude)) * COS(RADIANS(? - longitude))
                + SIN(RADIANS(?)) * SIN(RADIANS(latitude))
            )
        )) AS distance'))->addBinding([$unit, $lat, $lng, $lat], 'select');
        
        $subQuery->whereBetween('latitude',  [$latNorth, $latSouth]);
        $subQuery->whereBetween('longitude', [$lngEast,  $lngWest]);
        
        $query->from(DB::raw('(' . $subQuery->toSql() . ') as d'));
        $query->mergeBindings($subQuery->getQuery());
        $query->where('distance', '<=', $radius);
    }
}

// To use:

$latitude  =  29.4284595;
$longitude = -98.492433;

// Default radius is 10; default unit is miles.
Model::nearLatLong($latitude, $longitude)->get();