Radius Search in Yii. Include WhereBehavior and RadiusSearchBehavior in your model in order to search byPointRadius or insideBounds.

RadiusSearchBehavior.php

<?php

class RadiusSearchBehavior extends CActiveRecordBehavior
{
    public function byPointRadius($lat, $lng, $radius)
    {
        $radius = (float)$radius;
        $distance = "((ACOS(SIN(:lat * PI() / 180) * SIN(lat * PI() / 180) + COS(:lat * PI() / 180) * COS(lat * PI() / 180) * COS((:lng - lng) * PI() / 180)) * 180 / PI()) * 60 * 1.1515)";
        $condition = "lat BETWEEN " . ($lat - $radius / 69.2) . " AND " . ($lat + $radius / 69.2) . " AND lng BETWEEN " . ($lng - $radius / 69.2) . " AND " . ($lng + $radius / 69.2) . " AND $distance<=:radius";
        return $this->owner->where($condition, array('lat' => $lat, 'lng' => $lng, 'radius' => $radius));
    }

    public function insideBounds($nex, $ney, $swx, $swy)
    {
        return $this->owner->where('lat<=:nex AND lat>=:swx AND lng<=:ney AND lng>=:swy', array('nex' => $nex, 'ney' => $ney, 'swx' => $swx, 'swy' => $swy));
    }
    
}

WhereBehavior.php

<?php

class WhereBehavior extends CActiveRecordBehavior
{
    /**
     * Examples:
     *     User::model()->where("user_id=5");
     *     User::model()->where("user_id", 5);
     *     User::model()->where("user_id", ">", 5);
     *     User::model()->where("first_name=:token OR last_name=:token", array('token' => "Furber"));
     * @param mixed $col
     * @param mixed $op
     * @param mixed $val
     */
    public function where($col, $op = null, $val = null)
    {
        if (!$op && !$val)
            $this->owner->getDbCriteria()->addCondition($col);
        else if ($op && !$val)
            if (is_array($op))
                $this->owner->getDbCriteria()->mergeWith(array(
                    'condition' => $col,
                    'params' => $op,
                ));
            else
                $this->owner->getDbCriteria()->compare($col, $op);
        else
            $this->owner->getDbCriteria()->compare($col, $op . $val);
        return $this->owner;
    }

}