1.1,简介
MongoDB 是由 C++语言编写一个基于分布式文件存储的开源 NoSQL 数据库系统。在高负 载的情况下，可添加更多的节点，以保证服务性能。在许多场景下用于代替传统的关系型 数据库或键/值存储方式。旨在为 Web 应用提供可扩展的高性能数据存储解决方案。
MongoDB 提供了一个面向文档存储，操作起来比较简单和容易，可以存储比较复杂的 数据类型。最大的特点是支持的查询语言非常强大，语法优点类似于面向对象的查询语 言。几乎可以实现类似关系数据库单表查询的绝大部分功能，而且还支持对数据建立索 引。是一个面向集合的，模式自由的文档型数据库。
1.2,MongoDB 适用领域：
l 网站数据
l 分布式场景
l 缓存层
l 文档格式存储
1.3,逻辑结构
（1）文档（document）：是 mongodb 的核心概念，是 mongodb 逻辑存储的最小单元
（2）集合（collection）：多个文档组成集合
（3）数据库（database）：多个集合组成数据库
1.4,物理存储结构
1.4.1,数据存储结构
l 命名空间文件（ns）
l 数据文件（0,1,2）
1.4.2,日志存储结构
l 系统日志文件 logpath
l journal 日志文件
l oplog 复制操作日志文件
l 慢查询日志
1.5,数据类型
BSON 是 Binary JSON，是二进制的格式，能将 mongdb 的所有文档表示为字节字符串。
JSON 是一种轻量级的数据交换格式。它基于 JavaScript 的一个子集
1.5.1,BSON 的数据类型
l null，代表空或者不存在
l布尔，只有 true 和 false
l 数字，64 位浮点数
l 字符串，utf8 字符串
l 数组，值或者列表可表示为数组
l 对象，对象的数据
1.5.2,BSON 的特点
简单，简洁，容易理解、解析、记忆
1.5.3,命名规则
l 文档的键命名几乎所有 utf8 字符，只有少数例外：$开头；\0（空字符）；_下划线开头。
l 集合的命名几乎所有 utf8 字符，只有少数例外：$开头；\0（空字符）；system.开头；”” 空字符串。
l 数据库的命名几乎所有 utf8 字符，只有少数例外：””空字符串；\0；空格；. 点；\ ；
/。
二，安装搭建mongodb
1．安装mongodb
1.1,环境：
CentOS-6.8 192.168.25.32/24 MongoDB
1.2下载此次安装版本
[root@MongodDB tmp]# wget https://www.mongodb.com/dr/fastdl.mongodb.org/linux/mongodb-linux-x86_64-rhel62- 3.2.7.tgz/download
1.3,解压安装包，并移动到/usr/local/下
[root@MongodDB tmp]# tar zxvf mongodb-linux-x86_64-rhel62-3.2.7.tgz [root@MongodDB tmp]# mv mongodb-linux-x86_64-rhel62-3.2.7/ /usr/local/mongodb
1.4指定同一时间最多可开启的文件数
[root@MongodDB ~]# ulimit -n 1024 [root@MongodDB ~]# ulimit -n 65535 [root@MongodDB ~]# ulimit -n 65535
1.5,用户最多可开启的程序数目
[root@MongodDB ~]# ulimit -u 31994 [root@MongodDB ~]# ulimit -u 65535 [root@MongodDB ~]# ulimit -u 65535
1.6,创建数据目录和日志文件及目录，并创建相应配置文件
[root@MongodDB ~]# mkdir -p /data/mongodb1 [root@MongodDB ~]# mkdir -p /data/logs/mongodb [root@MongodDB ~]# touch /data/logs/mongodb/mongodb1.log [root@MongodDB ~]# cd /usr/local/mongodb/ [root@MongodDB mongodb]# ls bin GNU-AGPL-3.0 MPL-2 README THIRD-PARTY-NOTICES [root@MongodDB mongodb]# mkdir conf [root@MongodDB mongodb]# cat conf/mongodb1.conf port=27017 dbpath=/data/mongodb1 logpath=/data/logs/mongodb/mongodb1.log logappend=true fork=true maxConns=5000 storageEngine=mmapv1
1.7,启动MongoDB数据库,-f 指定配置文件
[root@MongodDB mongodb]# /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/mongodb1.conf [root@MongodDB mongodb]# /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/mongodb1.conf about to fork child process, waiting until server is ready for connections. forked process: 2016 child process started successfully, parent exiting [root@MongodDB mongodb]# netstat -anpt | grep mongod tcp 0 0 0.0.0.0:27017 0.0.0.0:* LISTEN 2016/mongod [root@MongodDB mongodb]# ps aux | grep mongdb root 2044 0.0 0.0 103324 892 pts/0 S+ 20:04 0:00 grep mongdb
1.8,设置开机自动启动
[root@MongodDB mongodb]# cat /etc/rc.local #!/bin/sh # # This script will be executed *after* all the other init scripts. # You can put your own initialization stuff in here if you don't # want to do the full Sys V style init stuff. touch /var/lock/subsys/local rm -f /data/mongodb1/mongod.lock /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/mongodb1.conf
1.9,连接数据库
[root@MongodDB mongodb]# /usr/local/mongodb/bin/mongo MongoDB shell version: 3.2.7 connecting to: test Welcome to the MongoDB shell. For interactive help, type "help". For more comprehensive documentation, see • http://docs.mongodb.org/ Questions? Try the support group • http://groups.google.com/group/mongodb-user Server has startup warnings: 2019-09-02T19:50:12.394+0800 I CONTROL [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended. 2019-09-02T19:50:12.394+0800 I CONTROL [initandlisten] 2019-09-02T19:50:12.395+0800 I CONTROL [initandlisten] 2019-09-02T19:50:12.395+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'. 2019-09-02T19:50:12.395+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never' 2019-09-02T19:50:12.395+0800 I CONTROL [initandlisten] 2019-09-02T19:50:12.395+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'. 2019-09-02T19:50:12.395+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never' 2019-09-02T19:50:12.395+0800 I CONTROL [initandlisten] \> show dbs local 0.078GB \> exit Bye
1.10,去除启动时的报错
[root@MongodDB mongodb]# echo never > /sys/kernel/mm/transparent_hugepage/enabled [root@MongodDB mongodb]# echo never > /sys/kernel/mm/transparent_hugepage/defrag [root@MongodDB mongodb]# vim .bash_profile [root@MongodDB mongodb]# cat .bash_profile alias mongo=/usr/local/mongodb/bin/mongo [root@MongodDB mongodb]# source .bash_profile
1.11,关闭服务的三种方法
方法一：
[root@MongodDB ~]# mongo > use admin switched to db admin > db.shutdownServer(); server should be down... 2019-09-02T20:19:49.361+0800 I NETWORK [thread1] trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed 2019-09-02T20:19:49.361+0800 W NETWORK [thread1] Failed to connect to 127.0.0.1:27017, reason: errno:111 Connection refused 2019-09-02T20:19:49.361+0800 I NETWORK [thread1] reconnect 127.0.0.1:27017 (127.0.0.1) failed failed > exit bye [root@MongodDB ~]# netstat -anpt |grep mongod
方法二：
[root@MongodDB ~]# /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/mongodb1.conf about to fork child process, waiting until server is ready for connections. forked process: 2081 child process started successfully, parent exiting [root@MongodDB ~]# netstat -anpt | grep mongod tcp 0 0 0.0.0.0:27017 0.0.0.0:* LISTEN 2081/mongod [root@MongodDB ~]# /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/mongodb1.conf --shutdown killing process with pid: 2081 [root@MongodDB ~]# netstat -anpt | grep mongod
方法三：
[root@MongodDB ~]# /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/mongodb1.conf about to fork child process, waiting until server is ready for connections. forked process: 2102 child process started successfully, parent exiting [root@MongodDB ~]# ps -ef |grep mongod root 2102 1 0 20:22 ? 00:00:00 /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/mongodb1.conf root 2118 1857 0 20:22 pts/0 00:00:00 grep mongod [root@MongodDB ~]# kill 2102 [root@MongodDB ~]# netstat -anpt | grep mongod [root@MongodDB ~]#
1.12,开启两个实例：
[root@MongodDB ~]# cd /usr/local/mongodb/conf/ [root@MongodDB conf]# ls mongodb1.conf [root@MongodDB conf]# cp mongodb{1,2}.conf [root@MongodDB conf]# ls mongodb1.conf mongodb2.conf [root@MongodDB conf]# cat mongodb2.conf port=27018 dbpath=/data/mongodb2 logpath=/data/logs/mongodb/mongodb2.log logappend=true fork=true maxConns=5000 storageEngine=mmapv1 [root@MongodDB conf]# mkdir /data/mongodb2 [root@MongodDB conf]# touch /data/logs/mongodb/mongodb2.log [root@MongodDB conf]# chmod 777 /data/logs/mongodb/mongodb2.log
1.13,编写启停脚本
[root@MongodDB conf]# cd /etc/init.d/ [root@MongodDB init.d]# cat mongodb #!/bin/bash INSTANCE=$1 ACTION=$2 case "$ACTION" in 'start') /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/"$INSTANCE".conf;; 'stop') /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/"$INSTANCE".conf --shutdown;; 'restart') /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/"$INSTANCE".conf --shutdown /usr/local/mongodb/bin/mongod -f /usr/local/mongodb/conf/"$INSTANCE".conf;; esac [root@MongodDB init.d]# chmod +x mongodb [root@MongodDB init.d]# /etc/init.d/mongodb mongodb1 start about to fork child process, waiting until server is ready for connections. forked process: 2139 child process started successfully, parent exiting [root@MongodDB init.d]# /etc/init.d/mongodb mongodb2 start about to fork child process, waiting until server is ready for connections. forked process: 2155 child process started successfully, parent exiting [root@MongodDB init.d]# netstat -anpt |grep mongod tcp 0 0 0.0.0.0:27017 0.0.0.0:* LISTEN 2139/mongod tcp 0 0 0.0.0.0:27018 0.0.0.0:* LISTEN 2155/mongod
到此mongodb已经搭建完毕了
2,基本操作
| 操作 | 作用 |
|---|---|
| show dbs | 查看当前示例下的数据库列表，等同于 show database |
| show users | 显示用户 |
| use <db_name> | 切换当前数据库 |
| db.help() | 显示数据库操作命令 |
| show collections | 显示当前数据库中的集合，等同于 show tables |
| db.mycoll.help() | 显示集合操作命令，mycoll 是当前下叫做 mycoll 的集合 |
| db.foo.find() | 对当前数据库中 foo 集合进行数据查找 |
[root@MongodDB ~]# mongo > show dbs local 0.078GB > show databases local 0.078GB > use benet switched to db benet > show dbs local 0.078GB > show tables > use local switched to db local > show tables startup_log system.indexes > use benet switched to db benet > db.user.insert({"id":1,"name":"Tom"}); WriteResult({ "nInserted" : 1 }) > show dbs benet 0.078GB local 0.078GB > show collections system.indexes user > db.user.find() { "_id" : ObjectId("5d6d0d5bea5345188da4699e"), "id" : 1, "name" : "Tom" } > bye
查看帮助
[root@MongodDB ~]# /usr/local/mongodb/bin/mongod --help [root@MongodDB ~]# mongo MongoDB shell version: 3.2.7 connecting to: test Server has startup warnings: 2019-09-02T20:31:36.534+0800 I CONTROL [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended. 2019-09-02T20:31:36.534+0800 I CONTROL [initandlisten] > help • db.help() help on db methods • db.mycoll.help() help on collection methods • sh.help() sharding helpers • rs.help() replica set helpers • help admin administrative help • help connect connecting to a db help • help keys key shortcuts • help misc misc things to know • help mr mapreduce • show dbs show database names • show collections show collections in current database • show users show users in current database • show profile show most recent system.profile entries with time >= 1ms • show logs show the accessible logger names • show log [name] prints out the last segment of log in memory, 'global' is default • use <db_name> set current database • db.foo.find() list objects in collection foo • db.foo.find( { a : 1 } ) list objects in foo where a == 1 • it result of the last line evaluated; use to further iterate • DBQuery.shellBatchSize = x set default number of items to display on shell • exit quit the mongo shell > > db.help() DB methods: • db.adminCommand(nameOrDocument) - switches to 'admin' db, and runs command [ just calls db.runCommand(...) ] • db.auth(username, password) • db.cloneDatabase(fromhost) • db.commandHelp(name) returns the help for the command • db.copyDatabase(fromdb, todb, fromhost) • db.createCollection(name, { size : ..., capped : ..., max : ... } ) • db.createUser(userDocument) • db.currentOp() displays currently executing operations in the db • db.dropDatabase() • db.eval() - deprecated • db.fsyncLock() flush data to disk and lock server for backups • db.fsyncUnlock() unlocks server following a db.fsyncLock() • db.getCollection(cname) same as db['cname'] or db.cname • db.getCollectionInfos([filter]) - returns a list that contains the names and options of the db's collections • db.getCollectionNames() • db.getLastError() - just returns the err msg string • db.getLastErrorObj() - return full status object • db.getLogComponents() • db.getMongo() get the server connection object • db.getMongo().setSlaveOk() allow queries on a replication slave server • db.getName() • db.getPrevError() • db.getProfilingLevel() - deprecated • db.getProfilingStatus() - returns if profiling is on and slow threshold • db.getReplicationInfo() • db.getSiblingDB(name) get the db at the same server as this one • db.getWriteConcern() - returns the write concern used for any operations on this db, inherited from server object if set • db.hostInfo() get details about the server's host • db.isMaster() check replica primary status • db.killOp(opid) kills the current operation in the db • db.listCommands() lists all the db commands • db.loadServerScripts() loads all the scripts in db.system.js • db.logout() • db.printCollectionStats() • db.printReplicationInfo() • db.printShardingStatus() • db.printSlaveReplicationInfo() • db.dropUser(username) • db.repairDatabase() • db.resetError() • db.runCommand(cmdObj) run a database command. if cmdObj is a string, turns it into { cmdObj : 1 }
2.1,Mongodb常用命令
列出所有数据库：show dbs
列出所有的集合：show collections
使用某个数据库：use kw
查看当前所在数据库：db
插入数据库：db.student.insert({“name”:”kinverwu”})
导入数据库：mongoimport --db test --collection restaurants --drop --file primer -dataset.json
-db test 想往哪个数据库里面导入
--collection restaurants 想往哪个集合中导入
--drop 把集合清空
--file primer-dataset.json 哪个文件
删除数据库：
删除所有数据：db.dropDatabase();
删除指定得数据：db.restaurants.remove({“borough”:”Manhattan”})
删除justOne : db.restaurants.remove({“borough”:”Queens”},{justOne:true})
修改数据库：db.student.update({“name”:”小明”},{$set:{“age”:16}});
更改所有匹配项目：db.student.update({“sex”:”男”},{$set:{“age”:33}},{multi:true});
完整替换:db.student.update({“name”:”小明”},{“name”:”大明”,”age”:16});
查找数据库：
查找所有：db.restaurants.find()
精确匹配：db.student.find({“score.shuxue”:70});
多个条件：db.student.find({“score.shuxue”:70,”age”:12})
大于条件：db.student.find({“score.yuwen”:{$gt:50}});
或者：db.student.find({$or:[{“age”:9},{“age”:11}]});