Men MongoDB va, albatta, MongoDB Java drayveri yordamida Java-da yig'ish quvurini yaratmoqdaman.
Men Mongo Shell-da o'zim xohlagan narsani qanday qilishni tushundim, lekin buni Java-ga qanday tarjima qilishni bilmayman, xususan, quyida ko'rsatilganidek, vergulli ob'ekt tushunchasini.
{$project: {sleep: {"date": 1, "hours": 1}}}
Buni amalga oshirishning eng yaxshi usuli haqida har qanday fikr bormi?
Buni amalga oshirishning ajoyib usullaridan biri ma'lum bo'ldi:
BasicDBObject project = new BasicDBObject("$project", new BasicDBObject("sleep", new BasicDBObject().append("date", 1).append("hours", 1)));
Keyin siz yig'ish buyrug'ini quyidagicha chaqirishingiz mumkin:
AggregationOutput output = collection.aggregate(commandOne, commandTwo, Project, CommandThree);
Umid qilamanki, bu yordam beradi :)
