geoNear查询 near查询的升级版

db.runCommand({
　　geoNear:<collection>,
　　near:[x,y],
　　minDistance:(对2d索引无效,对2dsphere有效),
　　maxDistance:
　　num:
　　...
})

> db.runCommand({geoNear:‘location‘,near:[1,2],maxDistance:10,num:1})
{
    "results" : [
        {
            "dis" : 0,
            "obj" : {
                "_id" : ObjectId("5b6b6fa872ff7510af7fc784"),
                "w" : [
                    1,
                    2
                ]
            }
        }
    ],
    "stats" : {
        "nscanned" : 3,
        "objectsLoaded" : 1,
        "avgDistance" : 0,
        "maxDistance" : 0,
        "time" : 3396
    },
    "ok" : 1
}

db.runCommand({geoNear:‘location‘,near:[1,2],maxDistance:10,num:2})
{
    "results" : [
        {
            "dis" : 0,
            "obj" : {
                "_id" : ObjectId("5b6b6fa872ff7510af7fc784"),
                "w" : [
                    1,
                    2
                ]
            }
        },
        {
            "dis" : 1,
            "obj" : {
                "_id" : ObjectId("5b6b6fa572ff7510af7fc783"),
                "w" : [
                    1,
                    1
                ]
            }
        }
    ],
    "stats" : {
        "nscanned" : 32,
        "objectsLoaded" : 2,
        "avgDistance" : 0.5,
        "maxDistance" : 1,
        "time" : 3340
    },
    "ok" : 1
}