distanceField in geoNear in geoNear-data-mongodb

Question

我用的是春季数据-mongodb。

1. 我可以使用聚合触发geoNear查询吗？
2. 我可以像在mongodb中那样在geoNear查询中指定geoNear。

下面是样例mongodb查询：

([
{
    $geoNear: {
        near: [
            28.45,
            77.34
        ],
        distanceField: "distance",
        maxDistance: 20,
        num: 5,
        query: {
            $or: [
                {
                    cuisines: {
                        '$in': [
                            'Mughlai',
                            'NorthIndian'
                        ]
                    }
                }
            ]
        }
    }
},
{
$unwind: '$ProducerTimeSlots'
}
])

Answer 1

您需要扩展聚合操作功能，GeoNearOperations类没有distanceField变量。

public class GeoNearOperationExt implements AggregationOperation {

private NearQuery nearQuery;

private String distanceField = "distance";

public GeoNearOperationExt(NearQuery nearQuery) {
    this.nearQuery = nearQuery;
}

/**
 * Default is distance
 * @return
 */
public String getDistanceField() {
    return distanceField;
}

/**
 * Set distanceField value Default is distance
 * @param distanceField
 */
public void setDistanceField(String distanceField) {
    this.distanceField = distanceField;
}



@Override
public DBObject toDBObject(AggregationOperationContext context) {
    DBObject dbObject = context.getMappedObject(nearQuery.toDBObject());
    dbObject.put("distanceField", distanceField);
    return new BasicDBObject("$geoNear", dbObject);
}
}

要在聚合中使用它，只需将其包含在聚合操作数组中，即传递给聚合函数的参数中。