小编Red*_*laf的帖子

我有订单集合，我正在从中获取数据，如下所示：

 [
  {
    "_id": "628216b7b30bb8aa80c8fd1a",
    "promotionsDetails": {
      "companyTotalPrice": 27,
      "promotionsData": [
        {
          "_id": "621de063bb5f9f0bf510897f",
          "price": 27,
          "companyId": "621dd85eb45ca2ae292d9a36"
        },
        {
          "_id": "621de063bb5f9f0bf510897d",
          "price": 19,
          "companyId": "621dd85eb45ca2ae292d9a32"
        }
      ]
    }
  },
  {
    "_id": "628214fcb30bb8aa80c8fd18",
    "promotionsDetails": {
      "companyTotalPrice": 46,
      "promotionsData": [
        {
          "_id": "621de063bb5f9f0bf510897f",
          "price": 46,
          "companyId": "621dd85eb45ca2ae292d9a32",
        }
      ]
    },
  }
]

我想做的是使用数组中每个对象中的 companyId objectId 从 Companies 集合中获取公司详细信息，如下所示：

    [
  {
    "_id": "628216b7b30bb8aa80c8fd1a",
    "promotionsDetails": {
      "companyTotalPrice": 27,
      "promotionsData": [
        {
          "_id": "621de063bb5f9f0bf510897f",
          "price": 27,
          "companyId": "621dd85eb45ca2ae292d9a36",
          "companyData": { "title": "..." }
        }, …