MongoDB

MongoDB

MongoDB 安装

https://www.mongodb.com/download-center/community 这是 MongoDB 的下载中心，选择需要下载的版本和操作系统。注意，MongoDB 的稳定版本都是偶数的。

Mac 系统下安装

Mac 系统可通过 Homebrew 安装 MongoDB 还是相对较简单的

$ brew update # 更新 Homebrew 数据包
$ brew install mongodb # 安装 MongoDB

Linux 系统安装

$ wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1604-4.2.2.tgz 
$ tar -xvf mongodb-linux-x86_64-ubuntu1604-4.2.2.tgz
$ mv mongodb-linux-x86_64-ubuntu1604-4.2.2 mongodb-4.2.2
$ export PATH=$PATH:/data/soft/mongodb-4.2.2/bin

安装校验

查看 MongoDB 版本，校验是否安装成功，出现以下信息则安装成功

$ mongo --version
MongoDB shell version v4.2.2

开启 MongoDB 实例

启动 MongoDB

通过 --dbpath 参数自定义目录路径，若省略 --dbpath 参数，将会使用系统默认的数据目录 (/data/db)

$ mongod --dbpath <自定义的目录路径>

检查是否成功启动

出现以下信息链接成功，默认端口为 27017

2018-01-28T21:20:50.190+0800 I CONTROL  [initandlisten] MongoDB starting : pid=10488 port=27017 dbpath=/Users/may/documents/mongodb/data 64-bit host=XXXX.local
2018-01-28T21:20:50.191+0800 I CONTROL  [initandlisten] db version v3.6.22018-01-28T21:20:50.191+0800 I CONTROL  [initandlisten] git version: 489d177dbd0f0420a8ca04d39fd78d0a2c539420
2018-01-28T21:20:50.956+0800 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. Number of files is 256, should be at least 1000
2018-01-28T21:20:50.979+0800 I FTDC     [initandlisten] Initializing full-time diagnostic data capture with directory '/Users/may/documents/mongodb/data/diagnostic.data'
2018-01-28T21:20:50.980+0800 I NETWORK  [initandlisten] waiting for connections on port 27017

打开 mongodb 客户端

打开本地控制台输入命令 mongo 连接到 mongodb 服务器

$ mongo

看到以下信息链接成功，会显示 mongodb 的版本号、链接地址，默认端口号为 27017

MongoDB shell version v3.6.2
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.6.2
Server has startup warnings: 
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] 
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] 
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] ** WARNING: This server is bound to localhost.
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] **          Remote systems will be unable to connect to this server. 
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] **          Start the server with --bind_ip <address> to specify which IP 
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] **          addresses it should serve responses from, or with --bind_ip_all to
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] **          bind to all interfaces. If this behavior is desired, start the
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] **          server with --bind_ip 127.0.0.1 to disable this warning.
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] 
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] 
2018-01-28T20:26:16.102+0800 I CONTROL  [initandlisten] ** WARNING: soft rlimits too low. Number of files is 256, should be at least 1000

展示所有数据库

> show dbs
admin   0.000GB
config  0.000GB
local   0.000GB

查看当前所连接的数据库

> db
test

查看当前数据库下的所有集合(数据表)

> show collections
demo_admin

切换/创建数据库

切换数据库，使用use之前我们不需要对数据库进行额外的创建，在mongo中会在需要的时候自己创建。

> use demo
switched to db demo

Nodejs 客户端链接 MongoDB

const MongoClient = require('mongodb').MongoClient;
const mongodbUrl = "mongodb://localhost:27017/demo";
const DB = {};
const userCollName = 'user'; //指定集合名
//封装初始化数据库方法
const init = () => {
    if(DB.db){
        return Promise.reject('mongodb has already initialized');
    }
    return MongoClient.connect(mongodbUrl)
        .then(db => {
            DB.db  = db;
            DB.userColl = db.collection(userCollName);
            //退出关闭mongodb数据库连接
            process.on('exit', () => db.close());
            console.log('mongodb initialized');
        });
}

问题汇总

db.collection is not a function

是因为 mongodb 版本是 3.0 以上版本，将 mongodb 版本指定安装为 2.2.34 即可解决，npm 安装

npm install mongodb@^2.2.34 --save

安装与部署