Mongodb 更新深度嵌套的子文档 [英] Mongodb update deeply nested subdocument

问题描述

我有一个深度嵌套的文档结构，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一个新的配置，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}}
                      )

我收到如果没有包含数组的相应查询字段，则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，您不能对每个键多次使用 $ 运算符，因此您必须对其余部分使用数值.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，如果您需要频繁更新数据，最好避免使用它们，而应考虑使用多个集合.

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:使 forecasts 成为它自己的集合，并假设您有一组固定的 level 值，使 level 成为一个对象而不是一个数组:

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}]
        }, 
      ]
    }
  }
}

然后你可以使用:

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

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