$geometry

$geometry 運算子會指定地理空間查詢的 GeoJSON 幾何物件。 它用於其他地理空間運算子內，以定義空間計算的圖形和點。

語法

{
  $geometry: {
    type: <GeoJSON type>,
    coordinates: <coordinates>
  }
}

參數

範例

我們來了解 stores 資料集範例 json 的使用方式。

{
    "_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：尋找距離點幾何圖形最近的商店

若要獲得更好的效能，請從建立必要的 2dsphere 索引開始。

db.stores.createIndex({ location: "2dsphere" })

查詢最多會擷取兩個最接近座標點 [46.2917， -62.6354] 的存放區，依鄰近程度排序。 它會使用 $near 運算符，依距離特定點來排序結果，協助尋找最接近指定位置的存放區。

db.stores.find({
  location: {
    $near: {
      $geometry: {
        type: "Point",
        coordinates: [46.2917, -62.6354]
      }
    }
  }
}, {
  name: 1,
  location: 1
}).limit(2)

此查詢傳回的前兩個結果是：

[
  {
    "_id": "59c355e9-586c-44f8-bbaf-a87989142119",
    "name": "Relecloud | Outdoor Furniture Shop - Chetside",
    "location": { "lat": 46.188, "lon": -62.2789 }
  },
  {
    "_id": "d3a9cc23-e6ae-4806-93ac-1ade2f624742",
    "name": "VanArsdel, Ltd. | Furniture Place - North Dustinside",
    "location": { "lat": 47.3426, "lon": -62.4031 }
  }
]

範例 2：尋找距離多邊形幾何圖形最近的商店

此查詢會尋找最多兩個存放區，其位置與所定義的矩形多邊形交集，其座標範圍從 [-80.0， -75.0] 到 [-55.0， -70.0]。

$geoIntersects 運算子會尋找與多邊形界限重疊或接觸的商店 - 非常適合用來識別哪些位置與特定地理區域有交集，無論是完全在內部，還是僅僅跨越邊緣。

db.stores.find({
  location: {
    $geoIntersects: {
      $geometry: {
        type: "Polygon",
        coordinates: [[
          [-80.0, -75.0],   // Bottom-left
          [-80.0, -70.0],   // Top-left
          [-55.0, -70.0],   // Top-right
          [-55.0, -75.0],   // Bottom-right
          [-80.0, -75.0]    // Close polygon
        ]]
      }
    }
  }
}, {
  name: 1,
  location: 1,
  city: 1
}).limit(2)

此查詢傳回的前兩個結果。

[
  {
    "_id": "6bba7117-d180-4584-b50c-a2f843e9c9ab",
    "name": "Wide World Importers | Craft Supply Mart - Heaneybury",
    "location": { "lat": -64.4843, "lon": -107.7003 },
    "city": "Heaneybury"
  },
  {
    "_id": "2fd37663-e0ff-41d0-9c5a-3aec86285daa",
    "name": "Relecloud | Cleaning Supply Closet - Patiencehaven",
    "location": { "lat": -70.6077, "lon": -105.9901 },
    "city": "Patiencehaven"
  }
]

範例 3：尋找距離多邊形幾何圖形最近的商店

此範例會擷取最多兩個商店，其位置落在定義的兩個矩形區域之一（MultiPolygon）中：一個區域靠近坐標 [120.0, -13.0] 至 [125.0, -10.0]，另一個區域靠近坐標 [44.0, -64.0] 至 [48.0, -61.0]。

它會使用具有 MultiPolygon 幾何的 $geoWithin 運算符來搜尋任何指定多邊形所包圍的商店，使其可用於同時查詢多個非相鄰地理區域。

db.stores.find({
  location: {
    $geoWithin: {
      $geometry: {
        type: "MultiPolygon",
        coordinates: [
          [[
            [120.0, -13.0],
            [120.0, -10.0],
            [125.0, -10.0],
            [125.0, -13.0],
            [120.0, -13.0]
          ]],
          [[
            [44.0, -64.0],
            [44.0, -61.0],
            [48.0, -61.0],
            [48.0, -64.0],
            [44.0, -64.0]
          ]]
        ]
      }
    }
  }
}, {
  name: 1,
  location: 1
}).limit(2)

此查詢傳回的前兩個結果是：

[
  {
    "_id": "6d70de9c-7b83-426d-81aa-f2173f97b64d",
    "name": "Fabrikam, Inc. | Footwear Haven - Port Erling",
    "location": { "lat": 45.641, "lon": -118.4963 }
  },
  {
    "_id": "96d48224-ce10-4a61-999a-8536d442f81a",
    "name": "Wide World Importers | Eyewear Bazaar - West Oletachester",
    "location": { "lat": 47.3461, "lon": -61.6605 }
  }
]