Программирование с нуля.

пятница, 7 февраля 2014 г.

MongoDB. Homework 5.

Homework: Homework 5.1 (Hands On)

db.posts.aggregate([{$unwind:"$comments"},{$group:{_id:"$comments.author",count:{$sum:1}}},{$sort:{"count":-1}},{$limit:1},{"$project":{_id:0,'tag':"$_id","count":1}}])

Kayce KenyonDevorah SmarttGisela LevinBrittny WarwickTamika SchildgenMariette Batdorf

Homework: Homework 5.2 (Hands On)

db.zips.aggregate([{$match:{$or:[{state:"NY"},{state:"CA"}]}},{$match:{pop:{$gt:25000}}},{$group:{state:"$state",_id:"$city",zip_codes:{$addToSet:"$_id"},population:{$avg:"$pop"}}}])

448055592167935718198242693777

Homework: Homework 5.3 (Hands On)

db.grades.aggregate([{$unwind:"$scores"},{$match:{"scores.type":{$ne:"quiz"}}},{$group:{_id:{student_id:"$student_id",class_id:"$class_id"},score:{$avg:"$scores.score"}}},{$group:{_id:"$_id.class_id","average":{"$avg":"$score"}}},{$sort:{"average":1}},{$limit:40}])