Mongo Array Filter返回所有文档

Question

我有下表

_id:"omde53@gmail.com"
    friendShips:Array
    0:Object
    friendEmail:"z@z.com"
    friendName:""
    isAccepted:true
    1:Object
    friendEmail:"y@y.com"
    friendName:""
    isAccepted:false
    2: Object
    friendEmail:"omerdemirci@windowslive.com"
    friendName:""
    isAccepted:"false"

我过滤时

$cursor = $collection->find( ['_id'=> $userEmail, 'friendShips.isAccepted' => false] 
        ,array('projection' => array('friendShips.friendEmail' => 1,'_id' => o
                    ,'friendShips.isAccepted'=>1)));

它也返回所有具有isAccepted true的数组...但是在过滤器中它说仅返回假值...我只想获取假值...但是为什么它返回文档数组中的所有值？如果ı使用'ne'运算符，它什么也不会返回吗？