通过

$bitsAllClear

$bitsAllClear 运算符用于匹配位掩码中指定的所有位位置都为空（即 0）的文档。 在需要根据字段的二进制表示形式中未设置的特定位筛选文档时，此运算符非常有用。

语法

{
  <field>: { $bitsAllClear: <bitmask> }
}

参数

参数 说明
field 要对其执行按位作的文档中的字段。
<bitmask> 一种位掩码，其中每个位位置指定字段值中必须为空 (0) 的相应位位置。

例子

请考虑商店集合中的这个示例文档。

{
  "_id": "a715ab0f-4c6e-4e9d-a812-f2fab11ce0b6",
  "name": "Lakeshore Retail | Holiday Supply Hub - Marvinfort",
  "location": {
    "lat": -74.0427,
    "lon": 160.8154
  },
  "staff": {
    "employeeCount": {
      "fullTime": 9,
      "partTime": 18
    }
  },
  "sales": {
    "salesByCategory": [
      {
        "categoryName": "Stockings",
        "totalSales": 25731
      }
    ],
    "revenue": 25731
  },
  "promotionEvents": [
    {
      "eventName": "Mega Savings Extravaganza",
      "promotionalDates": {
        "startDate": { "Year": 2023, "Month": 6, "Day": 29 },
        "endDate": { "Year": 2023, "Month": 7, "Day": 7 }
      },
      "discounts": [
        { "categoryName": "Stockings", "discountPercentage": 16 },
        { "categoryName": "Tree Ornaments", "discountPercentage": 8 }
      ]
    },
    {
      "eventName": "Incredible Discount Days",
      "promotionalDates": {
        "startDate": { "Year": 2023, "Month": 9, "Day": 27 },
        "endDate": { "Year": 2023, "Month": 10, "Day": 4 }
      },
      "discounts": [
        { "categoryName": "Stockings", "discountPercentage": 11 },
        { "categoryName": "Holiday Cards", "discountPercentage": 9 }
      ]
    },
    {
      "eventName": "Massive Deal Mania",
      "promotionalDates": {
        "startDate": { "Year": 2023, "Month": 12, "Day": 26 },
        "endDate": { "Year": 2024, "Month": 1, "Day": 2 }
      },
      "discounts": [
        { "categoryName": "Gift Bags", "discountPercentage": 21 },
        { "categoryName": "Bows", "discountPercentage": 19 }
      ]
    },
    {
      "eventName": "Super Saver Soiree",
      "promotionalDates": {
        "startDate": { "Year": 2024, "Month": 3, "Day": 25 },
        "endDate": { "Year": 2024, "Month": 4, "Day": 1 }
      },
      "discounts": [
        { "categoryName": "Tree Ornaments", "discountPercentage": 15 },
        { "categoryName": "Stockings", "discountPercentage": 14 }
      ]
    },
    {
      "eventName": "Fantastic Savings Fiesta",
      "promotionalDates": {
        "startDate": { "Year": 2024, "Month": 6, "Day": 23 },
        "endDate": { "Year": 2024, "Month": 6, "Day": 30 }
      },
      "discounts": [
        { "categoryName": "Stockings", "discountPercentage": 24 },
        { "categoryName": "Gift Wrap", "discountPercentage": 16 }
      ]
    },
    {
      "eventName": "Price Plunge Party",
      "promotionalDates": {
        "startDate": { "Year": 2024, "Month": 9, "Day": 21 },
        "endDate": { "Year": 2024, "Month": 9, "Day": 28 }
      },
      "discounts": [
        { "categoryName": "Holiday Tableware", "discountPercentage": 13 },
        { "categoryName": "Holiday Cards", "discountPercentage": 11 }
      ]
    }
  ],
  "company": "Lakeshore Retail",
  "city": "Marvinfort",
  "storeOpeningDate": { "$date": "2024-10-01T18:24:02.586Z" },
  "lastUpdated": { "$timestamp": { "t": 1730485442, "i": 1 } },
  "storeFeatures": 38
}

该 storeFeatures 字段是表示各种存储功能的位掩码整数。 每个位对应于一项功能：

Bit 价值 功能 / 特点
0 1 In-Store 取件
1 2 停车
2 4 轮椅通道
3 8 打开 24 小时
4 16 Pet-Friendly
5 32 免费 Wi-Fi
6 64 厕所
7 128 家庭送货

示例 1：查找未打开 24 小时且不允许宠物的商店

查找未开放 24 小时且不允许宠物的商店 （位 3 和 4）

db.stores.find({
  storeFeatures: {  $bitsAllClear: [3, 4] }},
  { _id: 1, name: 1, storeFeatures: 1 }).limit(5)

等效：

db.stores.find({
  storeFeatures: { $bitsAnySet: 24  }},  // 8 + 16
  { _id: 1, name: 1, storeFeatures: 1 }).limit(5)

示例输出：

[
  {
    "_id": "a715ab0f-4c6e-4e9d-a812-f2fab11ce0b6",
    "name": "Lakeshore Retail | Holiday Supply Hub - Marvinfort",
    "storeFeatures": 38
  },
  {
    "_id": "94792a4c-4b03-466b-91f6-821c4a8b2aa4",
    "name": "Fourth Coffee | Eyewear Shop - Lessiemouth",
    "storeFeatures": 225
  },
  {
    "_id": "1a2c387b-bb43-4b14-a6cd-cc05a5dbfbd5",
    "name": "Contoso, Ltd. | Smart Home Device Vault - Port Katarina",
    "storeFeatures": 36
  },
  {
    "_id": "e88f0096-4299-4944-9788-695c40786d97",
    "name": "Adatum Corporation | Handbag Shoppe - Lucienneberg",
    "storeFeatures": 135
  },
  {
    "_id": "bfb213fa-8db8-419f-8e5b-e7096120bad2",
    "name": "First Up Consultants | Beauty Product Shop - Hansenton",
    "storeFeatures": 135
  }
]

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