arrays - 更新 MongoDB 中的子文档数组

Question

我有一组学生，他们有姓名和电子邮件地址数组。学生文档看起来像这样:

{
  "_id": {"$oid": "56d06bb6d9f75035956fa7ba"},
  "name": "John Doe",
  "emails": [
    {
      "label": "private",
      "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="1a6a68736c7b6e7f5a707572747e757f34797577" rel="noreferrer noopener nofollow">[email protected]</a>"
    },
    {
      "label": "work",
      "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="5b2c3429301b313433353f343e75383436" rel="noreferrer noopener nofollow">[email protected]</a>"
    }
  ]
}

电子邮件子文档中的标签设置为每个文档都是唯一的，因此不能有两个条目具有相同的标签。

我的问题是，在更新学生文档时，我想实现以下目标:

• 添加带有新标签的电子邮件只需将具有给定标签和值的新子文档添加到数组
• 如果添加带有已存在标签的电子邮件，则应将现有的值设置为更新的数据

例如，使用以下数据更新时:

{
  "_id": {"$oid": "56d06bb6d9f75035956fa7ba"},
  "emails": [
    {
      "label": "private",
      "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="9af7ffdaf0f5f2f4fef5ffb4f9f5f7" rel="noreferrer noopener nofollow">[email protected]</a>"
    },
    {
      "label": "school",
      "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="e291818a8d8d8ea2888d8a8c868d87cc818d8f" rel="noreferrer noopener nofollow">[email protected]</a>"
    }
  ]
}

我希望电子邮件数组的结果是:

"emails": [
    {
      "label": "private",
      "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="e9848ca9838681878d868cc78a8684" rel="noreferrer noopener nofollow">[email protected]</a>"
    },
    {
      "label": "work",
      "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="2f58405d446f454047414b404a014c4042" rel="noreferrer noopener nofollow">[email protected]</a>"
    },
    {
      "label": "school",
      "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="d7a4b4bfb8b8bb97bdb8bfb9b3b8b2f9b4b8ba" rel="noreferrer noopener nofollow">[email protected]</a>"
    }
  ]

如何在 MongoDB 中实现此目的(可以选择使用 mongoose)？这是可能的还是我必须自己在应用程序代码中检查数组？

Answer 1

您可以尝试此更新，但仅对小型数据集有效:

mongo shell:

var data = {
    "_id": ObjectId("56d06bb6d9f75035956fa7ba"),
    "emails": [
        {
          "label": "private",
          "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="9ef3fbdef4f1f6f0faf1fbb0fdf1f3" rel="noreferrer noopener nofollow">[email protected]</a>"
        },
        {
          "label": "school",
          "value": "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="b9cadad1d6d6d5f9d3d6d1d7ddd6dc97dad6d4" rel="noreferrer noopener nofollow">[email protected]</a>"
        }
    ]
};

data.emails.forEach(function(email) {
    var emails = db.students.findOne({_id: data._id}).emails,
        query = { "_id": data._id },
        update = {};

    emails.forEach(function(e) {
        if (e.label === email.label) {
            query["emails.label"] = email.label;
            update["$set"] = { "emails.$.value": email.value };
        } else {
           update["$addToSet"] = { "emails": email }; 
        }
        db.students.update(query, update)
    });
});