MongoDB:在现有数组中添加一个数组

我正在尝试将"讲师"数组添加到现有的"营地"数组中。

层次结构看起来像这样：

owner = {
    email : 'john.smith@gmail.com',
    password : 'mypassword',
    firstName : 'john',
    lastName : 'smith',
    camps : [ 
                {
                    name : 'cubs-killeen',
                    location : 'killeen',
                    manager : {name: 'joe black', email: '', password: ''},
                    instructors : [
                        {
                            firstName : 'bill',
                            lastName : 'jones',
                            classes : []                        
                        }, 
                        {
                            firstName : 'jill',
                            lastName : 'jones',
                            classes : [],
                        },
                    ],
                    students : []
                }
            ]
};

我在MongoJS中使用Node Express，并且已经能够成功地添加所有者并添加"营地"，然而，当我尝试将"讲师"添加到出现问题的特定营地时，在"addCoacher"功能中。我没有收到错误消息，相反，它只是在camps数组中的项目后面添加"Instructionrs"数组。

如有任何帮助，我们将不胜感激。以下是我的完整代码，包含可工作的函数，然后是不可工作的，下面是我的mongodb输出（尽管是错误的）：

CampRepository = function(){};
CampRepository.prototype.addOwner = function(owner, callback){
    console.log(db);
    db.owners.save(owner, function(err, saved){
        if (err || !saved) {
            console.log('broke trying to add owner : ' + err);
            callback(err);
        } else {
            console.log('save was successful');
            callback(null, saved);
        }
    });
};

CampRepository.prototype.addCamp = function(ownerEmail, camp, callback){
    db.owners.update(
            {email: ownerEmail},
            {$push: {
                camps:{
                            name: camp.name,
                            location: camp.location,
                            managerName: camp.managerName,
                            managerEmail: camp.managerEmail,
                            managerPassword: camp.managerPassword,
                            managerPayRate: camp.managerPayRate,
                            instructors: [],
                            students: []
                        }
                    }
            }, function(err, saved){
                if (err || !saved) {
                    console.log('broke trying to add camp ' + err);
                    callback(err);
                } else {
                    console.log('save was successful');
                    callback(null, saved);
                }
    });
};

/*
    THIS IS THE ONE THAT DOESN'T WORK
*/
CampRepository.prototype.addInstructor = function(ownerEmail, campName, instructor, callback){
    db.owners.update(
            {email: ownerEmail, 'camps.name': campName},
            {$push: {
                        camps:{
                            instructors: {
                                firstName: instructor.firstName,
                                lastName: instructor.lastName,
                                email: instructor.email
                            },
                        }
                    }
            }, function(err, saved){
                if (err || !saved) {
                    console.log('broke trying to add camp ' + err);
                    callback(err);
                } else {
                    console.log('save was successful');
                    callback(null, saved);
                }
    });
};

输出

{ 
    "_id" : ObjectId("51c7b04d2746ef6078000001"), 
    "email" : "john.smith@gmail.com", 
    "firstName" : john, 
    "lastName" : smith, 
    "password" : "mypassword", 
    "camps" : [  
                {   
                    "name" : "cubs-killeen",     
                    "location" : "killeen",     
                    "managerName" : "bill jones",     
                    "managerEmail" : "bill@gmail.com",  
                    "managerPassword" : "secretpasscode",    
                    "instructors" : [ ],    
                    "students" : [ ] 
                },     
                {   "instructors" : {   "name" : "jon tisdale" } }
    ] 
}