[Mongodb] M-102 Week 2 Assignments

-----2.1 > homework.a() 3 ---- 2.2
	var prod1 = db.products.findOne({_id:ObjectId("507d95d5719dbef170f15c00")})
	prod1.term_years = 3
	db.products.update({_id:prod1._id},prod1)
	prod1.limits.sms.over_rate = 0.01
	db.products.update({_id:prod1._id},prod1)
	> homework.b()
	0.050.019031
	---- 2.3
	> db.products.find({"limits.voice":{$exists:1}}).count()
	3
	---- 2.4
	> db.products.ensureIndex({for:1})
	Q1 : 4
	Q2 : 4
	Q3 : YES
	---- 2.5
	// Trouver les items et boucler dessus
	> db.products.find({for:{$exists:1},for:"ac3"}).forEach( function(item) { printjson(item) } )
	// Réaliser l'update
	> db.products.find({for:{$exists:1},for:"ac3"}).forEach( function(item) { db.products.update({_id:item._id},{$inc:{price:2}}) } )
	> homework.c()
	89.5954.5