$bitNot

$bitNot 运算符对整数值执行按位 NOT 运算。 它将作数的所有位反转,将 1 转换为 0 和 0 转换为 1。 结果是输入值的按位补数。

语法

{
  $bitNot: <expression>
}

参数

参数 DESCRIPTION
expression 计算结果为整数的表达式。 运算符 $bitNot 对此值执行按位 NOT 运算。

例子

请考虑商店集合中的这个示例文档。

{
    "_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
                }
            ]
        }
    ]
}

示例 1:基本按位 NOT作

此查询对特定存储文档的工作人员计数字段执行按位反转。 倒排值可用于特殊权限标志、功能切换或位掩码作。 14 个结果的按位 NOT 为 -15,8 的按位 NOT 结果为 -9。 观察到的结果是由于两个的补数表示形式,其中 ~n = -(n+1)。

db.stores.aggregate([{
        $match: {
            _id: "26afb024-53c7-4e94-988c-5eede72277d5"
        }
    },
    {
        $project: {
            name: 1,
            fullTimeStaff: "$staff.totalStaff.fullTime",
            partTimeStaff: "$staff.totalStaff.partTime",
            invertedFullTime: {
                $bitNot: "$staff.totalStaff.fullTime"
            },
            invertedPartTime: {
                $bitNot: "$staff.totalStaff.partTime"
            }
        }
    }
])

此查询返回以下结果。

[
  {
    "_id": "26afb024-53c7-4e94-988c-5eede72277d5",
    "name": "First Up Consultants | Microphone Bazaar - South Lexusland",
    "fullTimeStaff": 14,
    "partTimeStaff": 8,
    "invertedFullTime": -15,
    "invertedPartTime": -9
  }
]

示例 2:将$bitNot与折扣百分比配合使用

此查询提取并处理特定存储的折扣信息,并为每个折扣百分比应用按位 NOT作。 按位 NOT 运算将反转所有位:20 变为 -21,17 变为 -18。

db.stores.aggregate([{
        $match: {
            _id: "26afb024-53c7-4e94-988c-5eede72277d5"
        }
    },
    {
        $unwind: "$promotionEvents"
    },
    {
        $match: {
            "promotionEvents.eventName": "Incredible Savings Showcase"
        }
    },
    {
        $unwind: "$promotionEvents.discounts"
    },
    {
        $project: {
            name: 1,
            eventName: "$promotionEvents.eventName",
            categoryName: "$promotionEvents.discounts.categoryName",
            discountPercentage: "$promotionEvents.discounts.discountPercentage",
            invertedDiscount: {
                $bitNot: "$promotionEvents.discounts.discountPercentage"
            }
        }
    }
])

此查询返回以下结果:

[
  {
    "_id": "26afb024-53c7-4e94-988c-5eede72277d5",
    "name": "First Up Consultants | Microphone Bazaar - South Lexusland",
    "eventName": "Incredible Savings Showcase",
    "categoryName": "Microphone Stands",
    "discountPercentage": 17,
    "invertedDiscount": -18
  },
  {
    "_id": "26afb024-53c7-4e94-988c-5eede72277d5",
    "name": "First Up Consultants | Microphone Bazaar - South Lexusland",
    "eventName": "Incredible Savings Showcase",
    "categoryName": "Condenser Microphones",
    "discountPercentage": 20,
    "invertedDiscount": -21
  }
]