Mongodb更新深层嵌套的子文档 [英] Mongodb update deeply nested subdocument

问题描述

我有一个深层嵌套的文档结构，如下所示:

I have a document structure that is deeply nested, like this:

{id: 1, 
 forecasts: [ { 
             forecast_id: 123, 
             name: "Forecast 1", 
             levels: [ 
                { level: "proven", 
                  configs: [
                            { 
                              config: "Custom 1",
                              variables: [{ x: 1, y:2, z:3}]
                            }, 
                            { 
                              config: "Custom 2",
                              variables: [{ x: 10, y:20, z:30}]
                            }, 
                    ]
                }, 
                { level: "likely", 
                  configs: [
                            { 
                              config: "Custom 1",
                              variables: [{ x: 1, y:2, z:3}]
                            }, 
                            { 
                              config: "Custom 2",
                              variables: [{ x: 10, y:20, z:30}]
                            }, 
                    ]
                }
            ]
        }, 
    ]

}

我正在尝试更新集合以插入新的配置，如下所示:

I'm trying to update the collection to insert a new config, that looks like this:

newdata =  {
  config: "Custom 1", 
  variables: [{ x: 111, y:2222, z:3333}]
}

我正在mongo中尝试这样的事情(在Python中):

I'm trying something like this in mongo (in Python):

db.myCollection.update({"id": 1, 
                        "forecasts.forecast-id": 123, 
                        "forecasts.levels.level": "proven", 
                        "forecasts.levels.configs.config": "Custom 1"
                         },
                         {"$set": {"forecasts.$.levels.$.configs.$": newData}}
                      )

我收到没有包含数组的相应查询字段，无法应用位置运算符"错误.在mongo中执行此操作的正确方法是什么?这是mongo v2.4.1.

I'm getting "Cannot apply the positional operator without a corresponding query field containing an array" error though. What is the proper way to do this in mongo? This is mongo v2.4.1.

推荐答案

不幸的是，每个键不能多次使用$运算符，因此其余部分必须使用数字值.如:

Unfortunately, you can't use the $ operator more than once per key, so you have to use numeric values for the rest. As in:

db.myCollection.update({
    "id": 1, 
    "forecasts.forecast-id": 123, 
    "forecasts.levels.level": "proven", 
    "forecasts.levels.configs.config": "Custom 1"
  },
  {"$set": {"forecasts.$.levels.0.configs.0": newData}}
)

MongoDB对更新嵌套数组的支持很差.因此，如果需要经常更新数据，最好避免使用它们，并考​​虑改用多个集合.

MongoDB's support for updating nested arrays is poor. So you're best off avoiding their use if you need to update the data frequently, and consider using multiple collections instead.

一种可能性:将forecasts设为自己的集合，并假设您有一组固定的level值，则将level设置为对象而不是数组:

One possibility: make forecasts its own collection, and assuming you have a fixed set of level values, make level an object instead of an array:

{
  _id: 123,
  parentId: 1,
  name: "Forecast 1", 
  levels: {
    proven: { 
      configs: [
        { 
          config: "Custom 1",
          variables: [{ x: 1, y:2, z:3}]
        }, 
        { 
          config: "Custom 2",
          variables: [{ x: 10, y:20, z:30}]
        }, 
      ]
    },
    likely: {
      configs: [
        { 
          config: "Custom 1",
          variables: [{ x: 1, y:2, z:3}]
        }, 
        { 
          config: "Custom 2",
          variables: [{ x: 10, y:20, z:30}]
        }, 
      ]
    }
  }
}

然后您可以使用以下命令进行更新:

Then you can update it using:

db.myCollection.update({
    _id: 123,
    'levels.proven.configs.config': 'Custom 1'
  },
  { $set: { 'levels.proven.configs.$': newData }}
)

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