Mongodb数据库命令端常用操作(五)

#只更新了一条数据，因为 multi 默认为false

4.$unset 删除字段

#查询name='laoda',user字段存在的数据中，删除age=65的age字段

> db.foo.find({},{'_id':0})
{ "name" : "yiwa", "age" : 78, "user" : { "phone" : [ 123, 13, 186 ] } }
{ "name" : "laoda", "age" : 65, "user" : { "phone" : [ 63, 188, 13, 186 ] } }
{ "name" : "sanwa", "age" : 56, "user" : { "phone" : [ 186 ] } }
{ "name" : "siwa", "age" : 15, "user" : { "phone" : [ 63, 137 ] } }
{ "age" : 65, "name" : "laoda" }
> db.foo.update({'name':'laoda','user':{$exists:true}},{$unset:{"age":65}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.foo.find({},{'_id':0})
{ "name" : "yiwa", "age" : 78, "user" : { "phone" : [ 123, 13, 186 ] } }
{ "name" : "laoda", "user" : { "phone" : [ 63, 188, 13, 186 ] } }
{ "name" : "sanwa", "age" : 56, "user" : { "phone" : [ 186 ] } }
{ "name" : "siwa", "age" : 15, "user" : { "phone" : [ 63, 137 ] } }
{ "age" : 65, "name" : "laoda" }

5.$push 数组下操作

#把value追加到field里面去，field一定要是数组类型才行，如果field不存在，会新增一个数组类型加进去

> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda" }
> db.array.update({'name':'laoda','age':65},{$push:{"phone":65}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda", "phone" : [ 65 ] }
> db.array.update({'name':'laoda','age':65},{$push:{"phone":[65,75,{'iphone':'188'},85]}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda", "phone" : [ 65, [ 65, 75, { "iphone" : "188" }, 85 ] ] }

6.$pushAll 数组下操作

#一次可以追加多个值到数组

> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda" }
> db.array.update({'name':'laoda','age':65},{$pushAll:{"phone":[111,222]}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda", "phone" : [ 111, 222 ] }
> db.array.update({'name':'laoda','age':65},{$pushAll:{"phone":[111,222]}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda", "phone" : [ 111, 222, 111, 222 ] }

7.$addToSet 数组操作

#增加一个值到数组内，而且只有当这个值不在数组内才增加 #插入2次发现，此值存在的时候不插入

> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda", "phone" : [ 111, 222, 111, 222, [ 111, 222 ] ] }
> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda", "phone" : [ 111, 222, 111, 222, [ 111, 222 ] ] }
> db.array.update({'name':'laoda','age':65},{$addToSet:{"phone":333}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.array.find({},{'_id':0})
{ "age" : 65, "name" : "laoda", "phone" : [ 111, 222, 111, 222, [ 111, 222 ], 333 ] }
> db.array.update({'name':'laoda','age':65},{$addToSet:{"phone":333}})
WriteResult({ "nMatched" : 1, "nUpserted"