小编JBo*_*one的帖子

我有一组对象（嵌套），我想从这些嵌套对象中拉出几个元素，然后将这些字段返回到数组中。下面是我的文档结构（从原始数据中模拟出来）

"detailLine": [
    {
        "name": "first",
        "value": {
            "lineNumber": 1,
            "subLineCode": " ",
            "detailLineCharges": {
                "allowedAmount": {
                    "amount": "11111",
                    "reasonCode": “aaaah”
                }
            }
        }
    },
    {
        "name": "first",
        "value": {
            "detailLineCharges": {
                "allowedAmount": {
                    "amount": "22222",
                    "reasonCode": “BBBB”
                }
            }
        }
    }
]

我希望看到这样的结果

details: [
  {
    amount:”11111”,
    reasonCode : “aaaah”
  },
  {
    amount : “22222”,
    reasonCode : “BBBB”
  }
]

我试过了

 db.collection.aggregate([
   {
     $match: {
       _id: "123456"
     }
   }, 
   {
     $project: {
       details: {
         $push {
           amount: "$detailLine.value.detailLineCharges.allowedAmount.amount",
           reasoncode: …