通过

$or （逻辑查询）

适用对象： MongoDB vCore

该 $or 运算符对表达式数组执行逻辑 OR作，并选择至少满足其中一个表达式的文档。

语法

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

参数

参数 类型 DESCRIPTION
expression 数组 表达式数组，其中至少一个表达式必须为 true 才能包含文档

例子

示例 1：基本 OR作

查找拥有 15 多名全职员工或 20 多名兼职员工的商店：

db.stores.find({
  $or: [
    { "staff.totalStaff.fullTime": { $gt: 15 } },
    { "staff.totalStaff.partTime": { $gt: 20 } }
  ]
})

输出：

  {
    _id: 'd924d148-9e01-4ab1-91d6-9daccb12a4dd',
    name: 'Fourth Coffee | Home Entertainment Gallery - East Adellahaven',
    location: { lat: -86.4872, lon: 130.9398 },
    staff: { totalStaff: { fullTime: 16, partTime: 14 } },
    sales: {
      totalSales: 179639,
      salesByCategory: [
        { categoryName: 'Home Theater Systems', totalSales: 18707 },
        { categoryName: 'Xbox Games', totalSales: 48276 },
        { categoryName: 'Sound Bars', totalSales: 43142 },
        { categoryName: 'Projector Mounts', totalSales: 43358 },
        { categoryName: 'Televisions', totalSales: 11325 },
        { categoryName: 'Streaming Devices', totalSales: 14831 }
      ]
    },
    promotionEvents: [
      {
        eventName: 'Massive Deal Mania',
        promotionalDates: {
          startDate: { Year: 2024, Month: 9, Day: 21 },
          endDate: { Year: 2024, Month: 9, Day: 29 }
        },
        discounts: [
          {
            categoryName: 'Home Theater Projectors',
            discountPercentage: 16
          },
          { categoryName: 'TV Mounts', discountPercentage: 17 },
          { categoryName: 'Projector Lamps', discountPercentage: 24 },
          { categoryName: 'Sound Bars', discountPercentage: 8 },
          { categoryName: 'Media Players', discountPercentage: 14 },
          {
            categoryName: 'Nintendo Switch Games',
            discountPercentage: 22
          }
        ]
      }
    ]
  }..

示例 2：复杂 OR作

查找总销售额超过 100000 或折扣超过 20%的商店：

db.stores.find({
  $or: [
    { "sales.totalSales": { $gt: 100000 } },
    { "promotionEvents.discounts.discountPercentage": { $gt: 20 } }
  ]
})

输出：

      {
        eventName: 'Bargain Blitz Bash',
        promotionalDates: {
          startDate: { Year: 2024, Month: 3, Day: 25 },
          endDate: { Year: 2024, Month: 4, Day: 3 }
        },
        discounts: [
          { categoryName: 'Pet Carriers', discountPercentage: 22 },
          { categoryName: 'Pet Collars', discountPercentage: 11 }
        ]
      },
      {
        eventName: 'Clearance Carnival',
        promotionalDates: {
          startDate: { Year: 2024, Month: 6, Day: 23 },
          endDate: { Year: 2024, Month: 6, Day: 30 }
        },
        discounts: [
          { categoryName: 'Cat Litter', discountPercentage: 18 },
          { categoryName: 'Pet Beds', discountPercentage: 8 }
        ]
      }..

示例 3：具有多个条件和数组的 OR

查找符合以下任何条件的商店：销售电子产品、拥有高员工计数或具有特定的促销活动：

db.stores.find({
  $or: [
    { "sales.salesByCategory.categoryName": { $in: ["Game Controllers", "Sound Bars", "Home Theater Projectors"] } },
    {
      $and: [
        { "staff.totalStaff.fullTime": { $gt: 10 } },
        { "staff.totalStaff.partTime": { $gt: 15 } }
      ]
    },
    {
      "promotionEvents": {
        $elemMatch: {
          "eventName": "Super Sale Spectacular",
          "discounts.discountPercentage": { $gt: 15 }
        }
      }
    }
  ]
})

性能注意事项

  • 独立计算数组中的每个 $or 条件
  • 尽可能使用索引来提高性能
  • 考虑最佳执行的条件顺序
  • $in用于$or同一字段的多个相等性检查
  • 使条件数量 $or 保持合理

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