Fatal error: Cannot redeclare class "Activity" in PHP - php

Question

// I really dont have any class like that I checked everywhere...even if I give it different name .. I get the same error
// This is my Php file which is an Entity for Doctrine
use Doctrine\ORM\Mapping AS ORM;
/**
* Description of Activity
*
* #author pawanadhikari
*/
/**
* #Entity
* #Table(name="pulse_activity")
*/
class Activity {
/**
* #var integer $id
* #Id
* #Column(type="integer")
* #GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var integer $patientId
* #Id
* #Column(type="integer")
*/
private $patientId;
/**
* #var integer $steps
* #Column(type="integer")
*/
private $steps;
/**
* #var double $calories
* #Column(type="double")
*/
private $calories;
/**
* #var double $distance
* #Column(type="double")
*/
private $distance;
/**
* #var integer $elevation
* #Column(type="integer")
*/
private $elevation;
/**
* #var integer $secondsActivitySoft
* #Column(type="integer")
*/
private $secondsActivitySoft;
/**
* #var integer $secondsActivityModerate
* #Column(type="integer")
*/
private $secondsActivityModerate;
/**
* #var integer $secondsActivityIntense
* #Column(type="integer")
*/
private $secondsActivityIntense;
/**
* #var string $date
* #Column(type="string")
*/
private $date;
/**
* #var string $timeStamp
* #Column(type="string")
*/
private $timeStamp;
/**
* #ManyToOne(targetEntity = "Person", inversedBy = "personActivities" )
* * #JoinColumn(name="patientId", referencedColumnName="id")
*
*/
protected $patientActivity;
public function getId() {
return $this->id;
}
public function getPatientId() {
return $this->patientId;
}
public function getSteps() {
return $this->steps;
}
public function getCalories() {
return $this->calories;
}
public function getDistance() {
return $this->distance;
}

Answer 1

you've declared your own unique namespace, right? you're just not showing it?
where are you getting the error? are you are calling these from custom runtime pages or is the error occuring when you generate the model.
This kind of error is common when include() and require() are used instead of include_once() or require_once() - particularly if used in an autoload function for the classes.