我来是因为我需要实现地理计算，但是，它不起作用。我目前正在使用包 globalsign/mgo

从文档我们有这个:

db.<collection>.find( { <location field> :
        { $near :
            { $geometry :
                { type : "Point" ,
                     coordinates : [ <longitude> , <latitude> ] } ,
                     $maxDistance : <distance in meters>,
                } 
            }
       }
  )

查询 2dsphere 索引:https://docs.mongodb.com/manual/tutorial/query-a-2dsphere-index/ 2dsphere 索引:https://docs.mongodb.com/manual/core/2dsphere/

所以我有以下内容:

import (
    "github.com/globalsign/mgo/bson"
    "shared/models"
    "time"
)

type Address struct {
    ID                 *bson.ObjectId `protobuf:"bytes,1,opt,name=id,proto3" json:"_id,omitempty" bson:"_id"`
    IsArchived         bool           `protobuf:"varint,2,opt,name=IsArchived,proto3" json:"is_archived,omitempty" bson:"is_archived"`
    CreatedAt          time.Time      `protobuf:"varint,3,opt,name=CreatedAt,proto3" json:"created_at,omitempty" bson:"created_at"`
    UpdatedAt          time.Time      `protobuf:"varint,4,opt,name=UpdatedAt,proto3" json:"update_at,omitempty" bson:"updated_at"`
    PlaceID            *bson.ObjectId `protobuf:"bytes,5,opt,name=PlaceID,proto3" json:"place_id,omitempty" bson:"place_id"`
    CountryCode        string         `protobuf:"bytes,6,opt,name=CountryCode,proto3" json:"country_code,omitempty" bson:"country_code,omitempty"`
    AdministrativeArea string         `protobuf:"bytes,7,opt,name=AdministrativeArea,proto3" json:"administrative_area,omitempty" bson:"administrative_area,omitempty"`
    Locality           string         `protobuf:"bytes,8,opt,name=Locality,proto3" json:"locality,omitempty" bson:"locality,omitempty"`
    PostalCode         string         `protobuf:"bytes,9,opt,name=PostalCode,proto3" json:"postal_code,omitempty" bson:"postal_code,omitempty"`
    Thoroughfare       string         `protobuf:"bytes,10,opt,name=Thoroughfare,proto3" json:"thoroughfare,omitempty" bson:"thoroughfare,omitempty"`
    Premise            string         `protobuf:"bytes,11,opt,name=Premise,proto3" json:"premise,omitempty" bson:"premise,omitempty"`
    Location           GeoJson `protobuf:"bytes,12,opt,name=Location,proto3" json:"location,omitempty" bson:"location,omitempty"`
}

type GeoJson struct {
    Type        string    `json:"-"`
    Coordinates []float64 `json:"coordinates"`
}

var addresses []*models.Address
collection := _session.DB(constants.DBName).C(documentName)
err := collection.Find(session, addressDocument, bson.M{
    "location": bson.M{
        "$near": bson.M{
            "$geometry": bson.M{
                "type":        "Point",
                "coordinates": []float64{ -115.172813, 36.101379 },
            },
            "$maxDistance": 5000000,
        },
    },
}) &addresses)

由此，我得到了以下错误:

"error processing query: ns=DBNAME.addressDocumentTree: GEONEAR field=location maxdist=5e+06 isNearSphere=0\nSort: {}\nProj: {}\n planner returned error: unable to find index for $geoNear query"

我在程序初始化时确保我的索引

// EnsureIndex
func EnsureAddressIndex(session *mgo.Session) error {

    _session := session.Copy()
    defer _session.Close()

    c := _session.DB(constants.DBName).C(addressDocument)
    // Might be needed one day
    pIndex := mgo.Index{
        Key:  []string{"location:2dsphere"},
        Bits: 26,
    }
    err := c.EnsureIndex(pIndex)
    if err != nil {
        return err
    }

    return nil
}

有什么想法吗？我有超过 20k 个地址，它们都有经纬度。

编辑 1

我尝试从 globalsign/mgo 切换到 gopkg.in/mgo.v2 但没有成功

最佳答案

终于找到问题了..实际上，我没有以正确的方式创建索引..

// EnsureIndex force ids to be unique
func EnsureAddressIndex(session *mgo.Session) error {

    _session := session.Copy()
    defer _session.Close()

    c := _session.DB(constants.DBName).C(addressDocument)
    // Might be needed one day
    pIndex := mgo.Index{
        Key:  []string{"$2dsphere:location"},
        Bits: 26,
    }
    err := c.EnsureIndex(pIndex)
    if err != nil {
        return err
    }

    return nil
}

在索引声明中，我有以下行:

pIndex := mgo.Index{
    Key:  []string{"location:2dsphere"},
    Bits: 26,
}

但是正确的写法是

pIndex := mgo.Index{
    Key:  []string{"$2dsphere:location"},
    Bits: 26,
}

希望对您有所帮助!

关于mongodb - 无法通过 2sphere 找到元素，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/54727125/