如何更新猫鼬中的特定字段? [英] How do update a specific field in mongoose?

问题描述

我有一个数据集

var JobSchema = Schema({
  candidates: [{
    user: { type: Schema.Types.ObjectId, ref: 'User'},
    status: { type: String, default: 'In Progress' },
  }]
});

我想找到一个特定的job's _id并更新一个特定的候选人字段，例如{ _id: 123, user: 12345, status: "In Progress" }

I want to find a specific job's _id and update a specific candidates' field such as { _id: 123, user: 12345, status: "In Progress" }

此操作的网址是---> localhost:3000/apply/:job_id/user_id

The url for this operation is ---> localhost:3000/apply/:job_id/user_id

例如

假设这是作业mongodb中当前保存的数据

Let say that this is the current saved data in job mongodb

  { 
   "_id" : 123, ---> job_id

   "candidates" : 
     [{ 
        "_id" : 234 , 
        "user": 345 , --> user_id
        "status" : "In Progress" 
     }, 

       { 
        "_id" : 345 , 
        "user": 678 , --> user_id
        "status" : "In Progress" 
      }]
    "__v" : 0 
  }

我如何只更新特定字段，比如说在mongodb中属于某个候选人的_id的status字段，这是我的尝试

How do i update only a specific field let say status field that belong to a certain candidates' _id in mongodb, Here's my attempt

          Job.update(
                    {
                        _id: req.params.job_id,
                    },
                    {
                        $set: {'candidates.$.status': 'Accepted'} ,
                    }, function(err, count) {
                        if (err) return next(err);
                        callback(err, count);
                    });

如果使用上述操作，我将收到此错误.

I will get this error If I use the above operation.

MongoError:位置运算符未从查询中找到所需的匹配项.未扩展的更新:候选人.$.status

MongoError: The positional operator did not find the match needed from the query. Unexpanded update: candidates.$.status

推荐答案

$ is the solution:

Job.update(
    { 
        _id: found._id, 
        'candidates.user': req.params.user_id
    },
    {
        $set: { 'candidates.$.status': 'Accepted'} },
    }, function(err, count) {
           if (err) return next(err);
           callback(err, count);
});

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