如何更新mongoDB中最嵌套的键答案

【问题标题】：How to update inner most nested key in mongoDB如何更新mongoDB中最嵌套的键
【发布时间】：2021-09-24 16:20:26
【问题描述】：

我有一份文件如下：

文档 1：

{ 
    "ARCM Sum" : {
        "MCA Go" : "60", 
        "Assess" : "5030", 
        "ActivitID" : "467144" 
        "Activity Checks" : [
            {
                "Frequency within Activity Description matches Activity Frequency" : "Exception", 
                "Activity Description contains > 20 word" : "Pass"
            }
        ]
       
        "Week" : "04-05-2021", 
        "Load Datetime" : "07-14-2021"
    }
}

文档 2：

{ 
    "ARCM Sum" : {
        "MCA Go" : "60", 
        "Assess" : "5030", 
        "ActivitID" : "467144" 
        "Activity Checks" : [
            {
                "Frequency within Activity Description matches Activity Frequency" : "Exception", 
                "Activity Description contains > 20 words" : "Pass"
            }
        ]
       
        "Week" : "04-05-2021", 
        "Load Datetime" : "07-14-2021"
    }
}

我需要在“Activity Description contains > 20 word”中将文档从“word”更新为“words”，所以

例如在文档 1 中有“Activity Description contains > 20 word”需要更新为“Activity Description contains > 20 words”

文档 2 将被忽略，因为它已经在“活动描述包含 > 20 个单词”中包含单词

【问题讨论】：

标签： mongodb mongodb-query aggregation-framework

【解决方案1】：

通常你会使用$rename，但因为它是数组中的一个字段，所以你不能直接这样做。在这里，您可以使用带有聚合管道的更新，$maps 相关文档：

这从 MongoDB 4.2 开始可用 Update with aggregation pipeline

db.test.update(
  { "ARCM Sum.Activity Checks.Activity Description contains > 20 word": {"$exists": true} },
  [{
    "$set": {
      "ARCM Sum.Activity Checks": {
        "$map": {
          "input": "$ARCM Sum.Activity Checks",
          "in": {
            "Frequency within Activity Description matches Activity Frequency": "$$this.Frequency within Activity Description matches Activity Frequency",
            "Activity Description contains > 20 words": "$$this.Activity Description contains > 20 word"
          }
        }
      }
    }
  }],
  { multi: true }
)

【讨论】：