$bitAnd

運算子會 $bitAnd 對整數值執行 bitwise AND 作業。 它會比較第一個作數的每個位與第二個作數的對應位。 如果這兩個位元都是 1，則對應的結果位元會設為 1。 否則，對應的結果位元會設為 0。

語法

{
  $bitAnd: [ <expression1>, <expression2>, ... ]
}

參數

範例

請參考商店集合中的此範例檔。

{
    "_id": "0fcc0bf0-ed18-4ab8-b558-9848e18058f4",
    "name": "First Up Consultants | Beverage Shop - Satterfieldmouth",
    "location": {
        "lat": -89.2384,
        "lon": -46.4012
    },
    "staff": {
        "totalStaff": {
            "fullTime": 8,
            "partTime": 20
        }
    },
    "sales": {
        "totalSales": 75670,
        "salesByCategory": [
            {
                "categoryName": "Wine Accessories",
                "totalSales": 34440
            },
            {
                "categoryName": "Bitters",
                "totalSales": 39496
            },
            {
                "categoryName": "Rum",
                "totalSales": 1734
            }
        ]
    },
    "promotionEvents": [
        {
            "eventName": "Unbeatable Bargain Bash",
            "promotionalDates": {
                "startDate": {
                    "Year": 2024,
                    "Month": 6,
                    "Day": 23
                },
                "endDate": {
                    "Year": 2024,
                    "Month": 7,
                    "Day": 2
                }
            },
            "discounts": [
                {
                    "categoryName": "Whiskey",
                    "discountPercentage": 7
                },
                {
                    "categoryName": "Bitters",
                    "discountPercentage": 15
                },
                {
                    "categoryName": "Brandy",
                    "discountPercentage": 8
                },
                {
                    "categoryName": "Sports Drinks",
                    "discountPercentage": 22
                },
                {
                    "categoryName": "Vodka",
                    "discountPercentage": 19
                }
            ]
        },
        {
            "eventName": "Steal of a Deal Days",
            "promotionalDates": {
                "startDate": {
                    "Year": 2024,
                    "Month": 9,
                    "Day": 21
                },
                "endDate": {
                    "Year": 2024,
                    "Month": 9,
                    "Day": 29
                }
            },
            "discounts": [
                {
                    "categoryName": "Organic Wine",
                    "discountPercentage": 19
                },
                {
                    "categoryName": "White Wine",
                    "discountPercentage": 20
                },
                {
                    "categoryName": "Sparkling Wine",
                    "discountPercentage": 19
                },
                {
                    "categoryName": "Whiskey",
                    "discountPercentage": 17
                },
                {
                    "categoryName": "Vodka",
                    "discountPercentage": 23
                }
            ]
        }
    ]
}

範例 1：基本位 AND 作業

此查詢會擷取特定商店的員工資訊，並計算全職和兼職員工數目之間的 ， bitwise AND 以建立權限旗標。

db.stores.aggregate([{
        $match: {
            _id: "40d6f4d7-50cd-4929-9a07-0a7a133c2e74"
        }
    },
    {
        $project: {
            name: 1,
            fullTimeStaff: "$staff.totalStaff.fullTime",
            partTimeStaff: "$staff.totalStaff.partTime",
            staffPermissionFlag: {
                $bitAnd: ["$staff.totalStaff.fullTime", "$staff.totalStaff.partTime"]
            }
        }
    }
])

此查詢會傳回下列結果。

[
  {
    "_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
    "name": "Proseware, Inc. | Home Entertainment Hub - East Linwoodbury",
    "fullTimeStaff": 19,
    "partTimeStaff": 20,
    "staffPermissionFlag": 16
  }
]

範例 2：多重值 $bitAnd

此查詢會根據單一存放區的多個數值欄位檢查位元許可權或組合旗標。

db.stores.aggregate([{
        $match: {
            _id: "40d6f4d7-50cd-4929-9a07-0a7a133c2e74"
        }
    },
    {
        $project: {
            name: 1,
            combinedFlag: {
                $bitAnd: [
                    "$staff.totalStaff.fullTime",
                    "$staff.totalStaff.partTime",
                    255
                ]
            }
        }
    }
])

此查詢會傳回下列結果。

[
  {
    "_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
    "name": "Proseware, Inc. | Home Entertainment Hub - East Linwoodbury",
    "combinedFlag": 16
  }
]