MongoDB修改器的使用2

1."$inc"的使用

主要用来增加数值，比如网站的访问量，点击量，流量等

1 db.games.insert({game:"pinball",user:"joe"})
2 db.games.find()
3 db.games.update({"game":"pinball","user":"joe"},{"$inc":{"score":50}})
4 db.games.update({"game":"pinball","user":"joe"},{"$inc":{"score":10000}})

运行结果分别为

1 /* 1 */
2 {
3     "_id" : ObjectId("575a37da8fd26400d774e00a"),
4     "game" : "pinball",
5     "user" : "joe",
6     "score" : 10150.0
7 }

db.games.update({"game":"pinball","user":"joe"},{"$inc":{"score":50}})

1 /* 1 */
2 {
3     "_id" : ObjectId("575a37da8fd26400d774e00a"),
4     "game" : "pinball",
5     "user" : "joe",
6     "score" : 10200.0
7 }