mongodb 更新update

1.$inc

用法：{$inc:{field:value}}

作用：對一個數字字段的某個field增加value

> db.test1.update({'name':'wang'},{$inc:{age:1}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "name" : "wang", "age" : 20, "sex" : "M" }

2.$set

用法：{$set:{field:value}}

作用：把文檔中某個字段field的值設為value

> db.test1.update({'name':'wang'},{$set:{'sex':'F'}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "name" : "wang", "age" : 20, "sex" : "F" }

3.$unset

用法：{$unset:{field:1}}

作用：刪除某個字段field

> db.test1.update({'name':'wang'},{$unset:{'sex':1}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "name" : "wang" }

4.$push

用法：{$push:{field:value}}

作用：把value追加到field里。注：field只能是數組類型，如果field不存在，會自動插入一個數組類型

> db.test1.update({'name':'wang'},{$push:{'sex':'F'}})

> db.test1.update({'name':'wang'},{$push:{'sex':'M'}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "name" : "wang", "sex" : [  "F",  "M" ] }

5.pushAll

用法：{$pushAll:{field:value_array}}

作用：用法同$push一樣，只是$pushAll可以一次追加多個值到一個數組字段內。

> db.test1.update({'name':'wang'},{$pushAll:{'sex':['M or F','M and F']}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "name" : "wang", "sex" : [  "F",  "M",  "M or F",  "M and F" ] }

> db.test1.update({'name':'wang'},{$push:{'sex':['M or F','M and F']}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "name" : "wang", "sex" : [  "F",  "M",  "M or F",  "M and F",  [  "M or F",  "M and F" ] ] }

6.$addToSet

用法：{$addToSet:{field:value}}

作用：加一個值到數組內，而且只有當這個值在數組中不存在時才增加。

> db.test1.update({'name':'wang'},{$addToSet:{'sex':['M or F','MF']}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "name" : "wang", "sex" : [ "F", "M", "M or F", "M and F", [ "M or F", "M and F" ], [ "M or F", "MF" ] ] }

7.$pop

用法：刪除數組內第一個值：{$pop:{field:-1}}、刪除數組內最后一個值：{$pop:{field:1}}

作用：用于刪除數組內的一個值

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "name" : "wang", "sex" : [  "F",  "M",  "M or F",  "M and F" ] }

> db.test1.update({'name':'wang'},{$pop:{'sex':1}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "name" : "wang", "sex" : [  "F",  "M",  "M or F" ] }

8.$pull

用法：{$pull:{field:_value}}

作用：從數組field內刪除一個等于_value的值

> db.test1.update({'name':'wang'},{$pull:{'sex':"F"}})

> db.test1.find({'name':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "name" : "wang", "sex" : [  "M",  "M or F" ] }

10.$rename

用法：{$rename:{old_field_name:new_field_name}}

作用：對字段進行重命名

> db.test1.update({'name':'wang'},{$rename:{'name':'names'}})

> db.test1.find({'name':'wang'})

> db.test1.find({'names':'wang'})

{ "_id" : ObjectId("58662477fb6a734e8f45133f"), "age" : 20, "names" : "wang", "sex" : [  "M",  "M or F" ] }