Radius search

gistfile1.php

$params = array();

$params['range'] = 10; //Miles
$params['zip'] = 19711; //Zip Code

//Get Lat,Lon from specified zip
$query = $this->db->query("SELECT lat,lon FROM default_zip_code WHERE zip_code=".$params['zip']);

if ($query->num_rows() > 0)
{
   $row = $query->row(); 

	$latitude = $row->lat;
	$longitude = $row->lon;
	if(!empty($params['range'])){
		$range = $params['range'];
	}else{
		$range = 10;
	}

	$this->db->select(' z.lat, z.lon, ( 3956 *2 * ATAN2( SQRT( POW( SIN( ( RADIANS( z.lat ) - RADIANS( '.$latitude.' ) ) /2 ) , 2 ) + COS( RADIANS( '.$latitude.' ) ) * COS( RADIANS( z.lat ) ) * POW( SIN( (
						RADIANS( z.lon ) - RADIANS( '.$longitude.' ) ) /2 ) , 2 ) ) , SQRT( 1 - ( POW( SIN( ( RADIANS( z.lat ) - RADIANS( '.$longitude.' ) ) /2 ) , 2 ) + COS( RADIANS( '.$longitude.' ) ) * COS( RADIANS( z.lat ) ) * POW( SIN( (
						RADIANS( z.lon ) - RADIANS( '.$longitude.' ) ) /2 ) , 2 ) ) ) ) ) AS distance',FALSE);
	$this->db->from('default_zip_codes z');
	$this->db->where('venues.zip = z.zip_code');

	$this->db->having('distance <='.$range,FALSE);
}