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?
你在保存的时候
categories
里面应该放Category
的ObjectId
,而不是完整的内容。题主后面那个执行正常的例子应该是因为
req.article.categories
里存的已经是Document
对象了,所以恰好跳过了 oid(ObjectID
)检查。详见 mongoose 3.8.13 源码
lib/schema/objectid.js
81 ~ 91 行。