转载

MongoDB 入门

什么是 MongoDB ?

MongoDB 是由C++语言编写的，是一个基于分布式文件存储的开源数据库系统。

在高负载的情况下，添加更多的节点，可以保证服务器性能。

MongoDB 旨在为 WEB 应用提供可扩展的高性能数据存储解决方案。

MongoDB 将数据存储为一个文档，数据结构由键值 (key=>value) 对组成。MongoDB 文档类似于 JSON 对象 。字段值可以包含其他文档，数组及文档数组。

安装

下载地址： http://www.mongodb.org/downloads

Windows中安装

在 Windows 系统上安装 MongoDB 数据库是件非常简单的事情，下载可执行安装文件(exe)，双击安装即可。

MongoDB 服务器运行命令： MongoDB 安装目录/bin/mongod.exe

MongoDB 客户端运行命令： MongoDB 安装目录/bin/mongo.exe

Ubuntu 安装

参考官方文档，我的环境 Ubuntu 14.04

# 下载密钥文件
$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv EA312927

# 在 source.list 中增加 MongoDB 源的配置
$ echo "deb http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.2 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.2.list

# 更新 apt 源
$ sudo apt-get update

# 安装 MongoDB
$ sudo apt-get install -y mongodb-org=3.2.6 mongodb-org-server=3.2.6 mongodb-org-shell=3.2.6 mongodb-org-mongos=3.2.6 mongodb-org-tools=3.2.6

上述命令执行完则安装完成，安装成功后 mongod 服务会自动启动，下面检测一下是否安装成功。

$ sudo service mongod status
mongod start/running, process 3841

如果没有启动那么手动启动 mongod 服务

# 启动服务
$ sudo service mongod start

# 停止服务
$ sudo service mongod stop

# 重启服务
$ sudo service mongod restart

开启后，通过 /var/log/mongodb/mongod.log 查看日志文件。

配置

配置文件放在 /etc/mongod.conf ，

默认访问端口为 27017 ，数据库文件存放目录为 /var/lib/mongodb ，日志文件目录为 /var/log/mongodb/mongod.log 。

# mongod.conf

# for documentation of all options, see:
#   http://docs.mongodb.org/manual/reference/configuration-options/

# Where and how to store data.
storage:
  dbPath: /var/lib/mongodb
  journal:
    enabled: true
#  engine:
#  mmapv1:
#  wiredTiger:

# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/mongod.log

# network interfaces
net:
  port: 27017
  bindIp: 127.0.0.1


#processManagement:

#security:

#operationProfiling:

#replication:

#sharding:

## Enterprise-Only Options:

#auditLog:

#snmp:

基本使用

# MongoDB 的相关命令
$ mongo --help
MongoDB shell version: 3.2.6
usage: mongo [options] [db address] [file names (ending in .js)]
db address can be:
  foo                   foo database on local machine
  192.169.0.5/foo       foo database on 192.168.0.5 machine
  192.169.0.5:9999/foo  foo database on 192.168.0.5 machine on port 9999
Options:
  --shell                             run the shell after executing files
  --nodb                              don't connect to mongod on startup - no
                                      'db address' arg expected
  --norc                              will not run the ".mongorc.js" file on
                                      start up
  --quiet                             be less chatty
  --port arg                          port to connect to
  --host arg                          server to connect to
  --eval arg                          evaluate javascript
  -h [ --help ]                       show this usage information
  --version                           show version information
  --verbose                           increase verbosity
  --ipv6                              enable IPv6 support (disabled by default)
  --disableJavaScriptJIT              disable the Javascript Just In Time
                                      compiler
  --enableJavaScriptProtection        disable automatic JavaScript function
                                      marshalling
  --ssl                               use SSL for all connections
  --sslCAFile arg                     Certificate Authority file for SSL
  --sslPEMKeyFile arg                 PEM certificate/key file for SSL
  --sslPEMKeyPassword arg             password for key in PEM file for SSL
  --sslCRLFile arg                    Certificate Revocation List file for SSL
  --sslAllowInvalidHostnames          allow connections to servers with
                                      non-matching hostnames
  --sslAllowInvalidCertificates       allow connections to servers with invalid
                                      certificates
  --sslFIPSMode                       activate FIPS 140-2 mode at startup

Authentication Options:
  -u [ --username ] arg               username for authentication
  -p [ --password ] arg               password for authentication
  --authenticationDatabase arg        user source (defaults to dbname)
  --authenticationMechanism arg       authentication mechanism
  --gssapiServiceName arg (=mongodb)  Service name to use when authenticating
                                      using GSSAPI/Kerberos
  --gssapiHostName arg                Remote host name to use for purpose of
                                      GSSAPI/Kerberos authentication

file names: a list of files to run. files have to end in .js and will exit after unless --shell is specified

从上面的帮助可以看到 mongo 的使用，现在使用 mongo 命令访问 MongoDB 服务

$ mongo
MongoDB shell version: 3.2.6
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

# 查看帮助
> 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
>

相关操作命令

# 连接数据库
$ mongo 127.0.0.1:27017

# 查看已有的数据库
> show dbs

# 切换/创建数据库
> use blogdb

# 显示当前数据库对象或集合
> db
blogdb

# 删除数据库
> db.dropDatabase()
{ "dropped" : "blogdb", "ok" : 1 }

# 向集合 user 中插入一条数据，如果集合不存在则创建
> db.user.insert({name:'hanks',age:22})
WriteResult({ "nInserted" : 1 })

# 查看当前数据库中是所以集合
> show collections
user
course

# 查询所以数据
> db.user.find()
{ "_id" : ObjectId("574021487ca7760c7927ea1b"), "name" : "hanks", "age" : 22 }
{ "_id" : ObjectId("5740214e7ca7760c7927ea1c"), "name" : "kiya", "age" : 22 }

# 条件查询
> db.user.find({name:'hanks'})
{ "_id" : ObjectId("574021487ca7760c7927ea1b"), "name" : "hanks", "age" : 22 }

# 删除
> db.user.remove({name:'hanks'})
WriteResult({ "nRemoved" : 1 })

# 覆盖更新
> db.user.update({name:'hanks'}, {age:'22'})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.user.find({name:'hanks'})
{ "_id" : ObjectId("5740239c7ca7760c7927ea20"), "age" : "22" }

# 更新某个字段
> db.user.update({name:'kiya'}, {$set:{age:'20'}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.user.find({name:'kiya'},)
{ "_id" : ObjectId("574023a37ca7760c7927ea21"), "name" : "kiya", "age" : "20" }