reactivemongo 中的“$centerSphere”查询

Question

我在这里找到 click here 和

我想在 reactivemongo 中进行“2d”索引，然后想在 reactivemongo

中使用以下查询

db.collName.find({
    loc: {
    $geoWithin: {
        $centerSphere: [
            [lng, lat], radius / 6371
        ]
    }
    }
})

如何在reactivemongo中实现？

我们将不胜感激。

Answer 1

在 reactivemongo 中，这个查询看起来像这样：

def findNear(lng: Double, lat: Double, radius: Double)(implicit fomrat: Format[T], ec: ExecutionContext): Enumerator[T] = {
        collection().
            find(Json.obj("loc" -> Json.obj("$geoWithin" -> Json.obj("$centerSphere" -> Json.arr(Json.arr(lng, lat), JsNumber(radius / 6371)))))).
            cursor[T].
            enumerate()
    }

我玩过简单的案例 class，来测试一下：

case class Company(name: String, loc: Point)

case class Point(lon: Double, lat: Double)

object Company extends MongoCollection[Company] {

    implicit val pointFormat: Format[Point]  = Json.format[Point]
    implicit val companyFormat: Format[Company] = Json.format[Company]

    val collectionName = "company"

    def findNear(lng: Double, lat: Double, radius: Double)(implicit ec: ExecutionContext): Enumerator[Company] = {
        collection().
            find(Json.obj("loc" -> Json.obj("$geoWithin" -> Json.obj("$centerSphere" -> Json.arr(Json.arr(lng, lat), JsNumber(radius / 6371)))))).
            cursor[Company].
            enumerate()
    }

}

并测试

object CompanySpec extends Specification with NoTimeConversions {

    sequential

    "geo spatial" should {

        val A = Company("A", Point(0, 0))
        val B = Company("B", Point(0, 1))
        val C = Company("C", Point(1, 1))
        val D = Company("D", Point(1, 0))

        Company.saveAll(List(A, B, C, D)).await()

        "return A " in {
            Company.findNear(0, 0, 1).collect().await() shouldEqual List(A)
        }

        "return A, B, C" in {

            Company.findNear(0, 0, 120).collect().await() shouldEqual List(A, B, D)
        }

        "return D" in {
            Company.findNear(0, 0, 240).collect().await() shouldEqual List(A, B, C, D)
        }

    }

}

reactivemongo 中的“$centerSphere”查询

"$centerSphere" query in reactivemongo

scala

geospatial

latitude-longitude

mongodb

reactivemongo