CastError：转换为嵌入的值失败答案

【问题标题】：CastError: Cast to embedded failed for valueCastError：转换为嵌入的值失败
【发布时间】：2019-04-18 15:53:59
【问题描述】：

我正在使用 Nodejs Express 和 Mongoose（“mongoose”：“^5.3.11”，）。我正在尝试将一些数据添加到集合中。我得到了所有正确的数据，但是当我使用 $push 时出现错误“CastError: Cast to embedded failed for value”，我一直在寻找不同的解决方案，但我无法弄清楚。

这是我的架构

var InstructorSchema= mongoose.Schema({
first_name:{
    type: String
},
last_name:{
    type:String
},
username:{
    type:String
},
email:{
    type:String
},
classes:[{
    class_id:{type:[mongoose.Schema.Types.ObjectId]},
    class_code:{type:String},        
    class_title:{type:String}
}] 
});

 var Instructor = module.exports = mongoose.model('Instructor', InstructorSchema);

这里我从表单中收集数据

info=[];
info['instructor_ID']=req.user.id;
info['instructor_username']=req.user.username;
info['class_id']=req.body.class_id;
info['class_code']=req.body.class_code;
info['class_title']=req.body.class_title;

这是我的数据

module.exports.register=function(info,callback){
instructor_ID=info['instructor_ID'];
instructor_username=info['instructor_username'];
class_id=info['class_id'];
class_code=info['class_code'];
class_title=info['class_title'];

这里是函数

var query = {username: instructor_username};
 Instructor.findOneAndUpdate(
    query,
    {
        $push: {
            "classes": {
                class_id: class_id, 
                class_code: class_code, 
                class_title: class_title
                }
        }
    },
    {   safe: true, 
        upsert: true
    },
    callback
    );

这是错误

    CastError: Cast to embedded failed for value "{ class_id: \'5be353ead45965c74d9e2853 \',\n  class_code: \'ART101 \',\n  class_title: \'Arts Fundamentals \' }" at path "classes"
at new CastError (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\error\cast.js:29:11)
at DocumentArray.cast (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\schema\documentarray.js:349:19)
at DocumentArray.cast (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\schema\documentarray.js:276:17)
at castUpdateVal (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\helpers\query\castUpdate.js:365:24)
at walkUpdatePath (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\helpers\query\castUpdate.js:165:24)
at castUpdate (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\helpers\query\castUpdate.js:79:18)
at model.Query._castUpdate (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\query.js:3861:10)
at castDoc (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\query.js:3889:18)
at model.Query.Query._findAndModify (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\query.js:3021:19)
at model.Query.Query._findOneAndUpdate (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\mongoose\lib\query.js:2732:8)
at C:\Users\user\Documents\Web Development\Node\elearning\node_modules\kareem\index.js:278:20
at _next (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\kareem\index.js:102:16)
at process.nextTick (C:\Users\user\Documents\Web Development\Node\elearning\node_modules\kareem\index.js:499:38)
at _combinedTickCallback (internal/process/next_tick.js:131:7)
at process._tickCallback (internal/process/next_tick.js:180:9)

【问题讨论】：

标签： node.js express mongoose

【解决方案1】：

最后，我改变了

class_id:{type:[mongoose.Schema.Types.ObjectId]},

对于

class_id:{type: Schema.Types.Mixed},

现在可以了

更新： 我的 class_id 最后有一个空格，我不知道为什么但是我使用 trim 函数删除了它。之后，该程序使用

正常工作

class_id:{type:[mongoose.Schema.Types.ObjectId]}

【讨论】：