无法查询从 CSV 转换而来的 JSON 数据

Not able to query the JSON data converted from CSV

我正在尝试 运行 以下 JSON 基本上来自 CSV 文件的数据。我只能在 db.learning.find({})

而当我尝试访问特定文档时,它没有给出任何输出。

JSON数据在下面

/* 1 */
{
    "_id" : ObjectId("624edebb78036379835d29a7"),
    "pmid" : 32339032,
    "ti" : "SAFETY AND EFFICACY OF DDP4-INHIBITORS FOR MANAGEMENT OF HOSPITALIZED GENERAL MEDICINE AND SURGERY PATIENTS WITH TYPE 2 DIABETES.",
    "year" : "2020",
    "population" : "['general medicine and surgery patients with T2D', 'general medicine and surgery patients with type 2 diabetes (T2D', 'n=266) and surgery (n=319) patients admitted with a blood glucose (BG) between 140 and 400 mg/dl, treated with']",
    "population_mesh" : "[{'cui': 'C0086343', 'cui_str': 'General medicine'}, {'cui': 'C0038895', 'cui_str': 'operative procedures'}]",
    "journal" : "Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists",
    "dois" : "['10.4158/EP-2019-0481']"
}

/* 2 */
{
    "_id" : ObjectId("624edebb78036379835d29a8"),
    "pmid" : 32339033,
    "ti" : "SAFETY AND EFFICACY OF DDP4-INHIBITORS FOR MANAGEMENT OF HOSPITALIZED GENERAL MEDICINE AND SURGERY PATIENTS WITH TYPE 2 DIABETES.",
    "year" : "2021",
    "population" : "['general medicine and surgery patients with T2D', 'general medicine and surgery patients with type 2 diabetes (T2D', 'n=266) and surgery (n=319) patients admitted with a blood glucose (BG) between 140 and 400 mg/dl, treated with']",
    "population_mesh" : "[{'cui': 'C0086343', 'cui_str': 'General medicine'}, {'cui': 'C0038895', 'cui_str': 'operative procedures'}]",
    "journal" : "Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists",
    "dois" : "['10.4158/EP-2019-0481']"
}

即) db.collectionName.find(year:"2020") 和其他类似的查询没有给出任何输出所以 JSON 数据或我的 mongo shell 命令有什么问题吗?

当我通过删除“”将 JSON 表单字符串数据的两个字段更改为字段数组时,我能够 运行 查询

reformed JSON 在这里给出了输出。 我不知道它是怎么发生的。但是我得到了结果

{
  "_id": {
    "$oid": "624edebb78036379835d29a7"
  },
  "pmid": 32339032,
  "ti": "SAFETY AND EFFICACY OF DDP4-INHIBITORS FOR MANAGEMENT OF HOSPITALIZED GENERAL MEDICINE AND SURGERY PATIENTS WITH TYPE 2 DIABETES.",
  "year": "2020",
  "population": [
    "general medicine and surgery patients with T2D",
    "general medicine and surgery patients with type 2 diabetes (T2D",
    "n=266) and surgery (n=319) patients admitted with a blood glucose (BG) between 140 and 400 mg/dl, treated with"
  ],
  "population_mesh": [
    {
      "cui": "C0086343",
      "cui_str": "General medicine"
    },
    {
      "cui": "C0038895",
      "cui_str": "operative procedures"
    }
  ],
  "journal": "Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists",
  "dois": "['10.4158/EP-2019-0481']"
}