带有引用数组的Mongoose模型模式：CastError：强制转换为ObjectId的值为“”

我用express.js和mongoosejs构build了一个博客网站。 一篇文章可能有一个或多个类别。 当我创build一个新的文章，我得到错误：

{ [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' } 

有人能帮我吗？ 相关代码如下所示：

Article模型定义如下：

 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); 

Category模型定义如下：

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

当我创build一个新的文章，并像这样保存：

 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); }); }; 

当调用create函数时，console.log（）输出如下所示：

 // console.log(req.body); { title: 'This is title', content: '<p>content here</p>', categories: [ { _id: '53c934bbf299ab241a6e0524', name: '1111', parent: '53c934b5f299ab241a6e0523', __v: 0, subs: [], sort: 1 } ], updated: [ 1405697477413 ] } // console.log(article); { title: 'This is title', content: '<p>content here</p>', _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' } 

我search了很多，但没有运气。 请帮帮我！

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更新：谢谢Gergo的回答。 但是，如果我用almoset更新存在的文章相同的代码，它工作正常！ 为什么？ 代码如下所示：

 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); }); }; 

这样的输出：

 // console.log(req.body); { _id: '53ca42f418bfb23c1e04df02', summary: 'tttt', title: 'tt', content: '<p>tttt</p>', __v: 2, categories: [ { _id: '53c934bbf299ab241a6e0524', name: '1111' } ], created: '2014-07-19T10:05:40.183Z' } // console.log(article); { _id: 53ca42f418bfb23c1e04df02, title: 'tt', content: '<p>tttt</p>', __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) } 

这工作正常。

Answer 1

您的文章架构需要一个ObjectIds数组：

 var ArticleSchema = new Schema({ ... categories: [{ type: Schema.ObjectId, ref: 'Category' }] }); 

但req.body包含一个类别对象：

 categories: [ { _id: '53c934bbf299ab241a6e0524', name: '1111', parent: '53c934b5f299ab241a6e0523', __v: 0, subs: [], sort: 1 } ] 

而且Mongoose不能将类别对象转换为ObjectId。 这就是你得到错误的原因。 确保req.body categories只包含id：

 { title: 'This is title', content: '<p>content here</p>', categories: [ '53c934bbf299ab241a6e0524' ], updated: [ 1405697477413 ] } 

Answer 2

请使用mongoose.Schema.Types.Mixed作为数据types的类别。 我有同样的问题与保存数据数组。 这个对我有用。

 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.Types.Mixed }] }); mongoose.model('Article', ArticleSchema);