mongo学习group操作以及java代码

/* 1 */
{"_id" : ObjectId("552a330e05c27486b9b9b650"),"_class" : "com.mongo.model.Orders","onumber" : "002","date" : ISODate("2014-01-03T16:03:00.000Z"),"cname" : "zcy","item" : {"quantity" : 1.0,"price" : 4.0,"pnumber" : "p002"}
}/* 2 */
{"_id" : ObjectId("552a331d05c275d8590a550d"),"_class" : "com.mongo.model.Orders","onumber" : "003","date" : ISODate("2014-01-04T16:03:00.000Z"),"cname" : "zcy","item" : {"quantity" : 10.0,"price" : 2.0,"pnumber" : "p001"}
}/* 3 */
{"_id" : ObjectId("552a333105c2f28194045a72"),"_class" : "com.mongo.model.Orders","onumber" : "003","date" : ISODate("2014-01-04T16:04:00.000Z"),"cname" : "zcy","item" : {"quantity" : 30.0,"price" : 4.0,"pnumber" : "p002"}
}/* 4 */
{"_id" : ObjectId("552a333f05c2b62c01cff50e"),"_class" : "com.mongo.model.Orders","onumber" : "004","date" : ISODate("2014-01-05T16:03:00.000Z"),"cname" : "zcy","item" : {"quantity" : 5.0,"price" : 4.0,"pnumber" : "p002"}
}


db.orders.group({key:{date:1,"item.pnumber" : 1},initial:{"total":0},reduce:function Reduce(doc,out){out.total&＃43;&＃61;doc.item.price}})


对out数据进一步处理db.orders.group({key: {date: 1},initial: {"total": 0,"money":0},reduce: function Reduce(doc, out) {out.total &＃43;&＃61; doc.item.quantity;out.money &＃43;&＃61; doc.item.price*doc.item.quantity},finalize:function Finalize(out){out.avg&＃61;out.money/out.totalreturn out}})


keyf &＃xff1a;对分组字段先进行处理然后分组db.orders.group({keyf: function keysss(doc){return {"month":doc.date.getDay()&＃43;1} },initial: {"total": 0,"money":0},reduce: function Reduce(doc, out) {out.total &＃43;&＃61; doc.item.quantity;out.money &＃43;&＃61; doc.item.price*doc.item.quantity},finalize:function Finalize(out){out.avg&＃61;out.money/out.totalreturn out}})


&＃64;Testpublic void group(){ApplicationContext applicationContext&＃61;new ClassPathXmlApplicationContext("classpath:111.xml");MongoTemplate mongoTemplate&＃61; (MongoTemplate) applicationContext.getBean("mongoTemplate");GroupBy groupBy&＃61;new GroupBy("date");BasicDBObject basicDBObject&＃61;new BasicDBObject();basicDBObject.put("total",0);basicDBObject.put("money",0);groupBy.initialDocument(basicDBObject);groupBy.reduceFunction("function Reduce(doc, out) {out.total &＃43;&＃61; doc.item.quantity;out.money &＃43;&＃61; doc.item.price*doc.item.quantity}");groupBy.finalizeFunction("function Finalize(out){\n" &＃43;" out.avg&＃61;out.money/out.total\n" &＃43;" return out\n" &＃43;" }");
// groupBy.finalizeFunction("function Finalize(out) {out.avg &＃61; out.money / out.totalreturn out}");GroupByResults orders &＃61; mongoTemplate.group("orders", groupBy, Object.class);}