发出model.save()函数时出现"process.nextTick( function () { throw err；});“错误

Question

我正在构建一个与mongo作为后端的Mean Stack应用程序。我的mongoose模型中有一个教堂模式，如下所示：

{
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var mongooseUniqueValidator = require('mongoose-unique-validator');
var sequenceGenerator = require('mongoose-sequence-plugin');

var unit = new Schema({
    unit_id: {type: String},
    unit_name:  {type: String, unique: true},
    unit_address: {type: String}
});

var schema = new Schema({
    church_id: {type: String},
    church_name: {type: String, required: true, unique: true},
    email:     {type: String, required: true, unique: true},
    parishname: {type: String},
    diocese: {type: String},
    units: [unit],
    church_reg_id: {type: String, required: true, unique: true},
    address: {type: String},
    city: {type: String},
    zipcode: {type: Number},
    state: {type: String},
    church_contact_no: {type: Number}
});

schema.plugin(mongooseUniqueValidator);
schema.plugin(sequenceGenerator, {
    field: 'church_id',
    startAt: '0001',
    prefix: 'CHURCH_',
    maxSaveRetries: 3
});


module.exports = mongoose.model('Church', schema);

现在，我正在尝试更新我当前模式中的Units子文档，该模式已经包含其他字段的数据。更新代码如下：

router.patch('/addunit/:uname/:uaddress', function (req, res, next) {

    console.log(req.params.uname);
    Church.findOne({church_id: req.body.church_id}, function (err, church) {
        if (err) {
            return res.status(500).json({
                title: 'No Church Details Found',
                error: err
            });
        }

        console.log(church.church_reg_id);
        console.log(church.church_name);
        church.units.push({
           unit_name: req.params.uname,
            unit_address: req.params.uaddress,
            unit_id: req.body.church_id + "Unit_" + req.params.uname
        });
        console.log(church.units);

        church.save(function (err, result) {
            if (err) {
                return res.status(500).json({
                    title: 'An error occured',
                    error: err
                });
            }
            res.status(201).json({
                message: 'Unit Added',
                obj: result
            })
        });

    });
});

现在的问题是代码成功运行，单位字段在后端成功更新，但在此之后我得到了下面的错误。

 D:\Church\node_modules\mongodb\lib\utils.js:123
    process.nextTick(function() { throw err; });
                                  ^

TypeError: callback is not a function
    at D:\Church\node_modules\mongoose\lib\model.js:267:5


     at D:\Church\node_modules\mongoose\lib\model.js:195:9
        at handleCallback (D:\Church\node_modules\mongodb\lib\utils.js:120:56)
        at D:\Church\node_modules\mongodb\lib\collection.js:1062:5
        at D:\Church\node_modules\mongodb-core\lib\connection\pool.js:469:18
        at _combinedTickCallback (internal/process/next_tick.js:73:7)
        at process._tickCallback (internal/process/next_tick.js:104:9)

请帮助找出问题所在。

Answer 1

能够使用findOneAndUpdate查询并使用$addToSet在教堂模式中添加子文档，从而成功地更新文档。

 Church.findOneAndUpdate({church_id: req.body.church_id}, update1, options, function (err, church) {
                    if (err) {
                        return res.status(500).json({
                            title: 'An error occured',
                            error: err
                        });
                    }
                    res.status(201).json({
                        message: 'Unit Added',
                        obj: church
                    })
                });

仍然不确定model.save()查询抛出错误的原因。