mongoBD学习(三)插入与查询数据
admin
2023-04-12 05:42:26
0

root@adela-vm:/opt/mongodb_simple# numactl --interleave=all bin/mongod -f conf/mongod.conf
about to fork child process, waiting until server is ready for connections.
forked process: 4904
child process started successfully, parent exiting

root@adela-vm:/opt/mongodb_simple# ./bin/mongo 127.0.0.1:12345
MongoDB shell version: 2.6.9
connecting to: 127.0.0.1:12345/test

> show dbs    //显示有几个数据库
admin  (empty)
local  0.078GB

> use adela   //切换到adela数据库,不需要事先定义
switched to db adela

> show dbs      //adela数据库没有增加内容,所以不现实
admin  (empty)
local  0.078GB
>

RDBMS中的表 对应 mongoDB中的集合collections ,插入内容为json格式
db.集合名(表).insert(json格式)
db.adela_collection.insert({"x":1})

显示所有的集合
> show collections   
adela_collection
system.indexes

插入数据
> db.adela_collection.insert({y:2})
WriteResult({ "nInserted" : 1 })
> db.adela_collection.find()
{ "_id" : ObjectId("5514f09641daf13c28f7bdb7"), "x" : 1 }
{ "_id" : ObjectId("5514f12b41daf13c28f7bdb8"), "y" : 2 }
 
_id是系统自动分配的,也可以自定义,但是 _id 不能重复
> db.adela_collection.insert({a:1,_id:1})
WriteResult({ "nInserted" : 1 })
> db.adela_collection.insert({a:2,_id:1})
WriteResult({
        "nInserted" : 0,
        "writeError" : {
                "code" : 11000,
                "errmsg" : "insertDocument :: caused by :: 11000 E11000 duplicate key error index: adela.adela_collection.$_id_  dup key: { : 1.0 }"
        }
})

查询adela_collection全表
> db.adela_collection.find()  //不加参数

查询x为1的数据
> db.adela_collection.find({x:1})
{ "_id" : ObjectId("5514f09641daf13c28f7bdb7"), "x" : 1 }
{ "_id" : ObjectId("5514f1d241daf13c28f7bdb9"), "x" : 1 }

循环插入一批数据
> for(i=1;i<11;i++)db.adela_collection.insert({z:i})
WriteResult({ "nInserted" : 1 })

> db.adela_collection.find()
{ "_id" : ObjectId("5514f09641daf13c28f7bdb7"), "x" : 1 }
{ "_id" : ObjectId("5514f12b41daf13c28f7bdb8"), "y" : 2 }
{ "_id" : ObjectId("5514f1d241daf13c28f7bdb9"), "x" : 1 }
{ "_id" : 1, "a" : 1 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe54"), "z" : 1 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe55"), "z" : 2 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe56"), "z" : 3 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe57"), "z" : 4 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe58"), "z" : 5 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe59"), "z" : 6 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5a"), "z" : 7 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5b"), "z" : 8 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5c"), "z" : 9 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5d"), "z" : 10 }

计数count
> db.adela_collection.find().count()
14

skip跳过多少条数据
limit限制返回多少条数据
sort使用排序

> db.adela_collection.find()
{ "_id" : ObjectId("5514f09641daf13c28f7bdb7"), "x" : 1 }
{ "_id" : ObjectId("5514f12b41daf13c28f7bdb8"), "y" : 2 }
{ "_id" : ObjectId("5514f1d241daf13c28f7bdb9"), "x" : 1 }
{ "_id" : 1, "a" : 1 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe54"), "z" : 1 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe55"), "z" : 2 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe56"), "z" : 3 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe57"), "z" : 4 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe58"), "z" : 5 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe59"), "z" : 6 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5a"), "z" : 7 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5b"), "z" : 8 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5c"), "z" : 9 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5d"), "z" : 10 }

> db.adela_collection.find().skip(4)
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe54"), "z" : 1 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe55"), "z" : 2 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe56"), "z" : 3 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe57"), "z" : 4 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe58"), "z" : 5 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe59"), "z" : 6 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5a"), "z" : 7 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5b"), "z" : 8 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5c"), "z" : 9 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe5d"), "z" : 10 }

> db.adela_collection.find().skip(4).limit(5)
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe54"), "z" : 1 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe55"), "z" : 2 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe56"), "z" : 3 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe57"), "z" : 4 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe58"), "z" : 5 }

> db.adela_collection.find().skip(4).limit(5).sort({z:1})
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe54"), "z" : 1 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe55"), "z" : 2 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe56"), "z" : 3 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe57"), "z" : 4 }
{ "_id" : ObjectId("5514f5eca1b17c0bb936fe58"), "z" : 5 }

相关内容

热门资讯

终于了解“天天斗地主究竟有挂吗... 网上科普关于“天天斗地主有没有挂”话题很是火热,小编也是针对天天斗地主作*弊开挂的方法以及开挂对应的...
【第一资讯】“开心安徽比鸡怎么... 有 亲,根据资深记者爆料开心安徽比鸡是可以开挂的,确实有挂(咨询软件无需...
终于了解“授权大厅牛牛开挂器?... 有 亲,根据资深记者爆料授权大厅牛牛是可以开挂的,确实有挂(咨询软件无需...
今日重磅消息“免安装麻将机干扰... 网上科普关于“免安装麻将机干扰器有没有挂”话题很是火热,小编也是针对免安装麻将机干扰器作*弊开挂的方...
2025金融大模型评测体系在沪... 证券时报记者 陈雨康 上海人工智能实验室与上海库帕思科技有限公司联合主办的“2025金融大模型评测体...
【今日要闻】“海贝大厅炸/金/... 网上科普关于“海贝大厅炸/金/花有没有挂”话题很是火热,小编也是针对海贝大厅炸/金/花作*弊开挂的方...
终于了解“杭州麻将到底是不是挂... 家人们!今天小编来为大家解答杭州麻将透视挂怎么安装这个问题咨询软件客服徽4282891的挂在哪里买很...
我来教教您“至尊宝牛牛究竟有挂... 我来教教您“至尊宝牛牛究竟有挂吗?”(太坑了原来有挂)您好,至尊宝牛牛这个游戏其实有挂的,确实是有挂...
【第一消息】“开心泉州麻将怎么... 有 亲,根据资深记者爆料开心泉州麻将是可以开挂的,确实有挂(咨询软件无需...
终于明白“网易麻将怎么装挂?”... 终于明白“网易麻将怎么装挂?”(果然有透视挂)您好,网易麻将这个游戏其实有挂的,确实是有挂的,需要了...