Node.js 我在获取记录时遇到以下错误

我收到此错误我在提交后收到此错误，我将获取记录，它将给出此错误。我已经给出了错误发生时的消息，它不是错误，然后执行其他函数。我得到一些设置标题错误，所以请让我知道我错在哪里

/home/hacker201501/VAIBHAO/ndd/node_modules/mongoose/lib/utils.js:419
        throw err;
              ^
Error: Can't set headers after they are sent.
    at ServerResponse.OutgoingMessage.setHeader (_http_outgoing.js:331:11)
    at ServerResponse.res.set.res.header (/home/hacker201501/VAIBHAO/ndd/node_modules/express/lib/response.js:524:10)
    at ServerResponse.res.json (/home/hacker201501/VAIBHAO/ndd/node_modules/express/lib/response.js:189:36)
    at Promise.<anonymous> (/home/hacker201501/VAIBHAO/ndd/app/controllers/categories_controller.js:110:26)
    at Promise.<anonymous> (/home/hacker201501/VAIBHAO/ndd/node_modules/mongoose/node_modules/mpromise/lib/promise.js:157:8)
    at Promise.EventEmitter.emit (events.js:107:17)
    at Promise.emit (/home/hacker201501/VAIBHAO/ndd/node_modules/mongoose/node_modules/mpromise/lib/promise.js:79:38)
    at Promise.reject (/home/hacker201501/VAIBHAO/ndd/node_modules/mongoose/node_modules/mpromise/lib/promise.js:106:15)
    at Promise.error (/home/hacker201501/VAIBHAO/ndd/node_modules/mongoose/lib/promise.js:89:15)
    at Query.execFind (/home/hacker201501/VAIBHAO/ndd/node_modules/mongoose/lib/query.js:1664:13)

---

我不明白发生了什么

我检查了你的代码，做了一些更改。 现在应该可以了，试试这个

exports.get_subcategory = function(req, res){
    var subcategoryData = req.query;
    User.findOne({
                    auth_token: req.query.auth_token
                }, function(user_error, user){
                        if (user_error) 
                            res.json({status: 'Error', message: 'Login require'});
                        SubCategory.find(
                                        {category: req.query.category}, 
                                        function(categoryError, subcatgory){
                                            if (categoryError) 
                                                res.json({status: 'Error', message: 'Category error'});

                                            res.json({status: 'OK', data: subcatgory});

                                        }
                        )

                }
    )
}

---

我想知道你是如何调用这个函数的。如果方法调用正确，请参阅下面的代码。谢谢，我已解决了错误。我调用我的函数时没有传递Id，所以它会出错。

exports.get_subcategory = function(req, res){
    var subcategoryData = req.query;
    User.findOne({
                    auth_token: req.query.auth_token
                }, function(user_error, user){
                        if (user_error) 
                            res.json({status: 'Error', message: 'Login require'});
                        SubCategory.find(
                                        {category: req.query.category}, 
                                        function(categoryError, subcatgory){
                                            if (categoryError) 
                                                res.json({status: 'Error', message: 'Category error'});

                                            res.json({status: 'OK', data: subcatgory});

                                        }
                        )

                }
    )
}