$maxDistance

L’opérateur $maxDistance est utilisé dans les requêtes géospatiales pour spécifier la distance maximale (en mètres) qui peut exister entre deux points. Il s’associe bien aux $near pour les recherches de localisation basées sur le rayon.

Syntaxe

{
  <location field>: {
    $near: {
      $geometry: {
        type: "Point",
        coordinates: [<longitude>, <latitude>]
      },
      $maxDistance: <distance in meters>
    }
  }
}

Paramètres

Paramètre	Descriptif
location field	Champ contenant les données géospatiales
coordinates	Tableau de [longitude, latitude] spécifiant le point central
$maxDistance	Distance maximale en mètres à partir du point central

Examples

Comprenons l’utilisation avec un exemple json à partir du jeu de données 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
}

Exemple 1 : Rechercher des magasins près d’un emplacement spécifique

La requête récupère jusqu’à deux magasins dans un rayon de 10 km des coordonnées de point donnés [-77.9951, -62.7339].

db.stores.find({
  location: {
    $near: {
      $geometry: {
        type: "Point",
        coordinates: [-77.9951,-62.7339]
      },
      $maxDistance: 10000  // 10 kilometers in meters
    }
  }
},
{
  name: 1,
  location: 1
}).limit(2)

La requête retourne le résultat suivant.

[
  {
     "_id": "66fd4cdd-ffc3-44b6-81d9-6d5e9c1f7f9a",
     "name": "Trey Research | Health Food Center - North Michelle",
     "location": { "lat": -77.9951, "lon": -62.7339 }
  }
]