node.js - 使用Mongoose定义的Schema包含数组，保存的时候出错CastError: Cast to ObjectId failed for value “[object Object]”-Questions et réponses sur le réseau chinois PHP

我使用Express.js和mongoose创建一个类似博客系统，一篇文章有若干个类别。

文章的Schema定义如下：

var mongoose = require('mongoose'), Schema = mongoose.Schema; var ArticleSchema = new Schema({ created: { type: Date, default: Date.now}, title: String, content: String, summary: String, categories: [{ type: Schema.ObjectId, ref: 'Category' }] }); mongoose.model('Article', ArticleSchema);

类别的Schema定义如下：

var mongoose = require('mongoose'), Schema = mongoose.Schema; var CategorySchema = new Schema({ parent: { type: Schema.ObjectId, }, name: String, subs: [CategorySchema] }); mongoose.model('Category', CategorySchema);

保存文章的代码如下：

exports.create = function(req, res) { console.log(req.body); var article = new Article(req.body); article.user = req.user; console.log(article); article.save(function(err) { if (err) { console.log(err); return res.jsonp(500, { error: 'Cannot save the article' }); } res.jsonp(article); }); };

保存的时候，这里的输出如下：

// console.log(req.body); { title: 'This is title', content: 'content here
', categories: [ { _id: '53c934bbf299ab241a6e0524', name: '1111', parent: '53c934b5f299ab241a6e0523', __v: 0, subs: [], sort: 1 } ], updated: [ 1405697477413 ] } // console.log(article); { title: 'This is title', content: 'content here
', _id: 53c93dc5b1c3b8e80cb4936b, categories: [], created: Fri Jul 18 2014 23:31:17 GMT+0800 (中国标准时间) } // console.log(err); { [CastError: Cast to ObjectId failed for value "[object Object]" at path "categories"] message: 'Cast to ObjectId failed for value "[object Object]" at path "categories"', name: 'CastError', type: 'ObjectId', value: [ [object Object] ], path: 'categories' }

出错就是在Category这个数组的地方。请问这个怎么解决呢？我已经搜索了很多，但是都没有结果，请大神帮忙。

更新
但是我使用几乎相同的代码更新一个已经存在的文章，就不会出现问题，应该不是类型的问题，代码如下：

var mongoose = require('mongoose'), Category = mongoose.model('Category'), _ = require('lodash'); exports.update = function(req, res) { console.log(req.body); var article = req.article; article = _.extend(article, req.body); console.log(article); article.save(function(err) { if (err) { return res.jsonp(500, { error: 'Cannot update the article' }); } res.jsonp(article); }); };

这段代码的输出如下：

// console.log(req.body); { _id: '53ca42f418bfb23c1e04df02', summary: 'tttt', title: 'tt', content: 'tttt
', __v: 2, categories: [ { _id: '53c934bbf299ab241a6e0524', name: '1111' } ], created: '2014-07-19T10:05:40.183Z' } // console.log(article); { _id: 53ca42f418bfb23c1e04df02, title: 'tt', content: 'tttt
', __v: 2, categories: [ { _id: 53c934bbf299ab241a6e0524, name: '1111', subs: [], sort: 0 } ], created: Sat Jul 19 2014 18:05:40 GMT+0800 (中国标准时间) }

这样就能正常工作，这是为什么呢？

if (value instanceof Document) { value.$__.wasPopulated = true; return value; } // setting a populated path if (value instanceof oid) { return value; } else if (Buffer.isBuffer(value) || !utils.isObject(value)) { throw new CastError('ObjectId', value, this.path); }