MongoDB中如何按食物名称向mealplan早餐项的completed数组添加日期

需要向用户餐单（mealplan）的早餐（breakfast）列表中按条件匹配指定名称的食物（例如名称为banana的食物项），将请求传入的日期添加到该食物的completed数组中。每个食物项都包含completed数组，每次发送请求时可对该数组执行日期添加或移除操作，当前需要优先实现向completed数组推送日期的功能。

{
    "_id": {
        "$oid": "616f193e9eb4ca14afc47fa8"
        },
    "date": {
        "$date": "2021-10-19T15:52:09.298Z"
    },
    "email": "john@live.com",
    "firstName": "john",
    "lastName": "doe",
    "password": "$2b$10$jKylT8MKsUl7ZS03EVi7SecQ1eWuB37J5rLVTU/C8VXBwkWQQo6EK",
    "role": "user",
    "token": "eyJhbGciOiJIQb-JA2kcKxWquDaM",
    "mealplan": {
        "dietType": ["Halal", "Vegetarian", "Vegan"],
        "religionType": ["Agnostic", "Muslim", "Christian", "Buddhist"],
        "ethinicType": ["Asian", "Native American"],
        "_id": "6179a178ba48312626059d44",
        "name": "first meal",
        "budget": 2000,
        "orac": 163,
        "medicinal": 0,
        "breakfast": [
        {
            "type": "breakfast",
            "completed": [],
            "fdcId": 1103194,
            "name": "Carrots, raw, salad",
            "numbers": 1,
            "unit": "100 grams",
            "recurring": {
            "startTime": "08:30",
            "endTime": "09:30",
            "startDate": "2021-10-28",
            "endDate": "2021-11-03",
            "daysofweek": []
            }
        },
        {
            "type": "breakfast",
            "completed": [],
            "name": "orange juice",
            "numbers": 1,
            "unit": "100 mililiters",
            "recurring": {},
            "orac": 10,
            "medicinal_value": 0,
            "nutrition": []
        },
        {
            "type": "breakfast",
            "name": "banana",
            "completed": [],
            "numbers": 1,
            "unit": "100 grams"
        }
        ]
    },
    "__v": 0
}

POST请求需要携带以下参数：

• 用户唯一标识（如用户_id、邮箱）
• 目标食物名称foodName
• 要操作的日期completedDate

添加日期到completed数组 #

使用Mongoose的arrayFilters匹配嵌套数组中对应名称的食物项，配合$addToSet实现无重复添加日期：

// 示例基于用户模型为 User 的场景
const { userId, foodName, completedDate } = req.body;

await User.updateOne(
  // 第一步：匹配目标用户
  { _id: userId },
  // 第二步：向匹配到的食物项的completed数组添加日期
  {
    $addToSet: {
      "mealplan.breakfast.$[targetFood].completed": completedDate
    }
  },
  // 第三步：指定数组过滤规则，匹配名称一致的早餐食物
  {
    arrayFilters: [
      { "targetFood.name": foodName }
    ]
  }
)

如果你允许同一日期重复添加，可以把$addToSet替换为$push。

移除completed数组中指定日期 #

如果后续需要实现移除功能，替换更新操作符为$pull即可：

await User.updateOne(
  { _id: userId },
  {
    $pull: {
      "mealplan.breakfast.$[targetFood].completed": completedDate
    }
  },
  {
    arrayFilters: [
      { "targetFood.name": foodName }
    ]
  }
)

内容的提问来源于stack exchange，提问作者ubaidh khatlani