Mongodb数据库基础入门知识有哪些

Mongodb介绍

Mongodb是一个基于分布式文件存储的数据库，由C++语言编写，为WEB应用提供可扩展的高性能数据存储解决方案

Mongodb是一款介于关系型数据库与非关系型数据库之间的产品， Mongodb是不同于以往的如redis、memcached,它是一种叫文档数据库，存储的是文档（bson-->json的二进制化）

特点：

最大的特点是支持查询语言非常强大，内部执行的引擎是JS解释器，把文档存储成bson结构，查询时将文档转换成JS对象文件，并通过熟悉JS语法来操作

同传统数据库比较：

1、传统数据库是结构化数据，有表结构，每一行内容是符合表结构，且列的类型也一样

2、mongodb数据库是以文档形式存储数据，每一个文档都是有自己独特的结构（js对象）与属性、值，因此它没有特定的规范与格式

Mongodb安装

官方网站：http://mongodb.org

下载最新的stable版本

[root@mingongge ~]# cd /usr/local/src/

[root@mingongge src]# wget https://www.mongodb.com/dr/fastdl.mongodb.org/linux/mongodb-linux-x86_64-rhel62-3.4.6.tgz

[root@Centos-2 src]# tar zxf mongodb-linux-x86_64-rhel62-3.4.6.tgz

[root@Centos-2 src]# cd mongodb-linux-x86_64-rhel62-3.4.6

[root@Centos-2 mongodb-linux-x86_64-rhel62-3.4.6]# cd bin/

[root@Centos-2 bin]# ll

total 277780

-rwxr-xr-x 1 root root 10431547 Jul 6 02:23 bsondump

#二进制导出（bson结构）

-rwxr-xr-x 1 root root 29870496 Jul 6 02:48 mongo

#客户端

-rwxr-xr-x 1 root root 54389424 Jul 6 02:48 mongod

#服务端

-rwxr-xr-x 1 root root 12771652 Jul 6 02:24 mongodump

#导出数据库

-rwxr-xr-x 1 root root 10783691 Jul 6 02:23 mongoexport

#导出易识别的json文档或CSV

-rwxr-xr-x 1 root root 10668482 Jul 6 02:23 mongofiles

-rwxr-xr-x 1 root root 10942731 Jul 6 02:23 mongoimport

-rwxr-xr-x 1 root root 10433507 Jul 6 02:24 mongooplog

-rwxr-xr-x 1 root root 53753432 Jul 6 02:48 mongoperf

-rwxr-xr-x 1 root root 14070941 Jul 6 02:24 mongoreplay

-rwxr-xr-x 1 root root 14127528 Jul 6 02:24 mongorestore

#导入数据库

-rwxr-xr-x 1 root root 30539024 Jul 6 02:48 mongos

#路由器（分片）

-rwxr-xr-x 1 root root 11003296 Jul 6 02:23 mongostat

#状态

-rwxr-xr-x 1 root root 10631445 Jul 6 02:24 mongotop

[root@Centos-2 src]# mv mongodb-linux-x86_64-rhel62-3.4.6 /usr/local/mongodb

[root@Centos-2 src]# cd /usr/local/mongodb/

启动服务

创建数据目录与日志目录

[root@Centos-2 ~]# mkdir /data/mongodb -p

[root@Centos-2 ~]# mkdir /data/mongodblog -p

[root@Centos-2 mongodb]# ./bin/mongod --dbpath /data/mongodb/ --logpath /data/mongodblog/mongo.log --fork --port 27017

about to fork child process, waiting until server is ready for connections.

forked process: 19027

child process started successfully, parent exiting

[root@Centos-2 mongodb]# lsof -i :27017

COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME

mongod 19027 root 7u IPv4 48419 0t0 TCP *:27017 (LISTEN)

参数说明：

--dbpath 指定数据存储目录

--logpath 指定日志存储目录

--fork 后台运行

--port 指定端口（默认27017）

连接数据库

[root@Centos-2 mongodb]# ./bin/mongo

MongoDB shell version v3.4.6

connecting to: mongodb://127.0.0.1:27017

MongoDB server version: 3.4.6

Server has startup warnings:

2017-07-29T10:36:50.683+0800 I STORAGE [initandlisten]

2017-07-29T10:36:50.683+0800 I STORAGE [initandlisten] ** WARNING: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine

2017-07-29T10:36:50.683+0800 I STORAGE [initandlisten] ** See http://dochub.mongodb.org/core/prodnotes-filesystem

2017-07-29T10:36:51.494+0800 I CONTROL [initandlisten]

2017-07-29T10:36:51.494+0800 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.

2017-07-29T10:36:51.494+0800 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.

2017-07-29T10:36:51.494+0800 I CONTROL [initandlisten] ** WARNING: You are running this process as the root user, which is not recommended.

2017-07-29T10:36:51.494+0800 I CONTROL [initandlisten]

2017-07-29T10:36:51.495+0800 I CONTROL [initandlisten]

2017-07-29T10:36:51.495+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.

2017-07-29T10:36:51.495+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'

2017-07-29T10:36:51.495+0800 I CONTROL [initandlisten]

2017-07-29T10:36:51.495+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.

2017-07-29T10:36:51.496+0800 I CONTROL [initandlisten] ** We suggest setting it to 'never'

2017-07-29T10:36:51.496+0800 I CONTROL [initandlisten]

2017-07-29T10:36:51.496+0800 I CONTROL [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 7671 processes, 65535 files. Number of processes should be at least 32767.5 : 0.5 times number of files.

2017-07-29T10:36:51.496+0800 I CONTROL [initandlisten]

重启mongodb服务后重新登陆

[root@Centos-2 mongodb]# ./bin/mongo

MongoDB shell version v3.4.6

connecting to: mongodb://127.0.0.1:27017

MongoDB server version: 3.4.6

> show databases;

admin 0.000GB

local 0.000GB

> show dbs; #查看当前的数据库

admin 0.000GB #管理数据库

local 0.000GB