$polygon

El operador $polygon define un polígono para las consultas geoespaciales, lo que permite encontrar ubicaciones dentro de una forma irregular. El operador es útil para consultar ubicaciones dentro de límites geográficos complejos.

Syntax

{
  <location field>: {
    $geoWithin: {
      $geometry: {
        type: "Polygon",
        coordinates: [
          [[<longitude1>, <latitude1>], ..., [<longitudeN>, <latitudeN>], [<longitude1>, <latitude1>]]
        ]
      }
    }
  }
}

Parámetros

Parámetro	Description
location field	Campo que contiene los datos geoespaciales
coordinates	Matriz de pares de coordenadas que forman el polígono. Los puntos primero y último deben ser idénticos para cerrar el polígono

Examples

Vamos a comprender el uso con un JSON de ejemplo del conjunto de datos stores.

{
  "_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
}

Ejemplo 1: Búsqueda en un polígono

La consulta recupera almacenes que se encuentran dentro de una región de polígono personalizada en función de las coordenadas proporcionadas.

db.stores.find({
  location: {
    $geoWithin: {
      $geometry: {
        type: "Polygon",
        coordinates: [[
          [-141.9922, 16.8331],  // VanArsdel Picture Frame Store
          [-112.7858, -29.1866], // First Up Consultants Microphone Bazaar
          [-38.4071, -47.2548],  // Fabrikam Car Accessory Outlet
          [-141.9922, 16.8331]   // Close the polygon by repeating first point
        ]]
      }
    }
  }
},
{
  name: 1,
  location: 1
}).limit(2)

Los dos primeros resultados devueltos por esta consulta son:

[
  {
      "_id": "4a417727-a002-4c80-a01f-bc9526b300a5",
      "name": "Northwind Traders | Bed and Bath Deals - East Duane",
      "location": {
        "type": "Point",
        "coordinates": [-46.1444, -60.9697]
      }
    },
    {
      "_id": "1e27040c-7242-4970-8893-e5738e1bc1ca",
      "name": "Northwind Traders | Seasonal Decoration Bazaar - Cassidyberg",
      "location": {
        "type": "Point",
        "coordinates": [-44.3617, -81.2186]
      }
    }
]