• MongoDB数据库(一):基本操作


    1.NoSQL的概念

    "NoSQL"一词最早于1998年被用于一个轻量级的关系数据库的名字
    随着web2.0的快速发展,NoSQL概念在2009年被提了出来
    NoSQL最常见的解释是"non-relational","Not Only SQL"也被很多人接受,指的是非关系型数据库

    2.关系型数据库和非关系型的区别

    关系型数据库很强大,但是并不能很好的应付所有的场景.关系型数据库的扩展性差,大数据下IO压力大,表结构更改困难

    非关系型数据库易扩展,大数据量高性能,灵活的数据模型,高可用

    3.MongoDB数据库的优势

    • 易扩展:去掉关系型数据库的关系型特性,数据之间无关系,非常容易扩展
    • 大数据量,高性能:得益于无关系性,数据库的结构简单,有非常高的读写性能,尤其是在大数据量下,同样表现优秀
    • 灵活的数据模型:无需事先为要存储的数据建立字段,随时可以存储自定义的数据格式

    4.安装及启动MongoDB数据库

    4.1 安装EPEL源

    [root@localhost ~]# yum list | grep epel
    epel-release.noarch                        7-11                        @extras  
    htop.x86_64                                2.2.0-3.el7                 @epel    
    libdb4.x86_64                              4.8.30-13.el7               @epel    
    libdb4-devel.x86_64                        4.8.30-13.el7               @epel    
    python2-pip.noarch                         8.1.2-7.el7                 @epel    
    [root@localhost ~]# yum install -y epel-release                 # MongoDB包含在EPEL源里面,所以在安装MongoDB必须先安装EPEL源
    Loaded plugins: fastestmirror
    Loading mirror speeds from cached hostfile
    Resolving Dependencies
    --> Running transaction check
    ---> Package epel-release.noarch 0:7-11 will be reinstalled
    --> Finished Dependency Resolution
    
    Dependencies Resolved
    
    ==========================================================================================================
        Package                      Arch                   Version                 Repository              Size
    ==========================================================================================================
    Reinstalling:
        epel-release                 noarch                 7-11                    extras                  15 k
    
    Transaction Summary
    ==========================================================================================================
    Reinstall  1 Package
    
    Total download size: 15 k
    Installed size: 24 k
    Downloading packages:
    epel-release-7-11.noarch.rpm                                                       |  15 kB  00:00:00     
    Running transaction check
    Running transaction test
    Transaction test succeeded
    Running transaction
        Installing : epel-release-7-11.noarch                                                               1/1 
        Verifying  : epel-release-7-11.noarch                                                               1/1 
    
    Installed:
        epel-release.noarch 0:7-11                                                                              
    
    Complete!
    [root@localhost ~]# ls /etc/yum.repos.d/
    CentOS-Base.repo  epel.repo  epel-testing.repo
    

    4.2 安装MongoDB数据库

    [root@localhost ~]# yum clean all               # 清除yum缓存
    Loaded plugins: fastestmirror
    Cleaning repos: base code epel extras updates
    Cleaning up everything
    Maybe you want: rm -rf /var/cache/yum, to also free up space taken by orphaned data from disabled or removed repos
    Cleaning up list of fastest mirrors
    [root@localhost ~]# yum makecache               # 重新生成yum缓存文件
    Loaded plugins: fastestmirror
    Determining fastest mirrors
    epel/x86_64/metalink                                                               | 7.3 kB  00:00:00     
        * epel: mirrors.aliyun.com
    base                                                                               | 3.6 kB  00:00:00     
    code                                                                               | 2.9 kB  00:00:00     
    epel                                                                               | 4.7 kB  00:00:00     
    extras                                                                             | 3.4 kB  00:00:00     
    updates                                                                            | 3.4 kB  00:00:00     
    (1/21): base/7/x86_64/filelists_db                                                 | 7.1 MB  00:00:01     
    (2/21): base/7/x86_64/primary_db                                                   | 6.0 MB  00:00:00     
    (3/21): base/7/x86_64/other_db                                                     | 2.6 MB  00:00:00     
    (4/21): code/primary_db                                                            |  40 kB  00:00:00     
    (5/21): epel/x86_64/group_gz                                                       |  88 kB  00:00:00     
    (6/21): code/filelists_db                                                          | 688 kB  00:00:01     
    (7/21): epel/x86_64/updateinfo                                                     | 1.0 MB  00:00:00     
    (8/21): epel/x86_64/prestodelta                                                    |  11 kB  00:00:00     
    (9/21): code/other_db                                                              | 2.2 kB  00:00:00     
    (10/21): epel/x86_64/primary_db                                                    | 6.6 MB  00:00:01     
    (11/21): extras/7/x86_64/filelists_db                                              | 231 kB  00:00:00     
    (12/21): extras/7/x86_64/prestodelta                                               |  47 kB  00:00:00     
    (13/21): extras/7/x86_64/primary_db                                                | 180 kB  00:00:00     
    (14/21): base/7/x86_64/group_gz                                                    | 166 kB  00:00:05     
    (15/21): updates/7/x86_64/prestodelta                                              | 358 kB  00:00:00     
    (16/21): updates/7/x86_64/filelists_db                                             | 2.2 MB  00:00:00     
    (17/21): extras/7/x86_64/other_db                                                  | 118 kB  00:00:00     
    (18/21): updates/7/x86_64/other_db                                                 | 351 kB  00:00:00     
    (19/21): epel/x86_64/other_db                                                      | 3.2 MB  00:00:01     
    (20/21): updates/7/x86_64/primary_db                                               | 2.5 MB  00:00:00     
    (21/21): epel/x86_64/filelists_db                                                  |  11 MB  00:00:10     
    Metadata Cache Created
    [root@localhost ~]# yum install -y mongodb mongodb-server               # 安装MongoDB数据库
    Loaded plugins: fastestmirror
    Loading mirror speeds from cached hostfile
        * epel: mirrors.aliyun.com
    Resolving Dependencies
    --> Running transaction check
    ---> Package mongodb.x86_64 0:2.6.12-6.el7 will be installed
    --> Processing Dependency: v8 >= 3.14.5.10 for package: mongodb-2.6.12-6.el7.x86_64
    --> Processing Dependency: libboost_filesystem-mt.so.1.53.0()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
    --> Processing Dependency: libboost_program_options-mt.so.1.53.0()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
    --> Processing Dependency: libpcap.so.1()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
    --> Processing Dependency: libstemmer.so.0()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
    --> Processing Dependency: libtcmalloc.so.4()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
    --> Processing Dependency: libv8.so.3()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
    --> Processing Dependency: libyaml-cpp.so.0.5()(64bit) for package: mongodb-2.6.12-6.el7.x86_64
    ---> Package mongodb-server.x86_64 0:2.6.12-6.el7 will be installed
    --> Running transaction check
    ---> Package boost-filesystem.x86_64 0:1.53.0-27.el7 will be installed
    ---> Package boost-program-options.x86_64 0:1.53.0-27.el7 will be installed
    ---> Package gperftools-libs.x86_64 0:2.6.1-1.el7 will be installed
    ---> Package libpcap.x86_64 14:1.5.3-11.el7 will be installed
    ---> Package libstemmer.x86_64 0:0-2.585svn.el7 will be installed
    ---> Package v8.x86_64 1:3.14.5.10-25.el7 will be installed
    ---> Package yaml-cpp.x86_64 1:0.5.1-1.el7.2 will be installed
    --> Finished Dependency Resolution
    
    Dependencies Resolved
    
    ==========================================================================================================
        Package                          Arch              Version                         Repository       Size
    ==========================================================================================================
    Installing:
        mongodb                          x86_64            2.6.12-6.el7                    epel             43 M
        mongodb-server                   x86_64            2.6.12-6.el7                    epel            6.6 M
    Installing for dependencies:
        boost-filesystem                 x86_64            1.53.0-27.el7                   base             68 k
        boost-program-options            x86_64            1.53.0-27.el7                   base            156 k
        gperftools-libs                  x86_64            2.6.1-1.el7                     base            272 k
        libpcap                          x86_64            14:1.5.3-11.el7                 base            138 k
        libstemmer                       x86_64            0-2.585svn.el7                  epel             67 k
        v8                               x86_64            1:3.14.5.10-25.el7              epel            3.0 M
        yaml-cpp                         x86_64            1:0.5.1-1.el7.2                 epel            176 k
    
    Transaction Summary
    ==========================================================================================================
    Install  2 Packages (+7 Dependent packages)
    
    Total download size: 54 M
    Installed size: 164 M
    Downloading packages:
    (1/9): boost-filesystem-1.53.0-27.el7.x86_64.rpm                                   |  68 kB  00:00:03     
    (2/9): boost-program-options-1.53.0-27.el7.x86_64.rpm                              | 156 kB  00:00:05     
    (3/9): libpcap-1.5.3-11.el7.x86_64.rpm                                             | 138 kB  00:00:00     
    (4/9): gperftools-libs-2.6.1-1.el7.x86_64.rpm                                      | 272 kB  00:00:04     
    (5/9): libstemmer-0-2.585svn.el7.x86_64.rpm                                        |  67 kB  00:00:03     
    (6/9): mongodb-server-2.6.12-6.el7.x86_64.rpm                                      | 6.6 MB  00:00:01     
    (7/9): v8-3.14.5.10-25.el7.x86_64.rpm                                              | 3.0 MB  00:00:01     
    (8/9): yaml-cpp-0.5.1-1.el7.2.x86_64.rpm                                           | 176 kB  00:00:00     
    (9/9): mongodb-2.6.12-6.el7.x86_64.rpm                                             |  43 MB  00:00:30     
    ----------------------------------------------------------------------------------------------------------
    Total                                                                     1.5 MB/s |  54 MB  00:00:36     
    Running transaction check
    Running transaction test
    Transaction test succeeded
    Running transaction
        Installing : boost-filesystem-1.53.0-27.el7.x86_64                                                  1/9 
        Installing : 1:yaml-cpp-0.5.1-1.el7.2.x86_64                                                        2/9 
        Installing : boost-program-options-1.53.0-27.el7.x86_64                                             3/9 
        Installing : gperftools-libs-2.6.1-1.el7.x86_64                                                     4/9 
        Installing : 1:v8-3.14.5.10-25.el7.x86_64                                                           5/9 
        Installing : libstemmer-0-2.585svn.el7.x86_64                                                       6/9 
        Installing : 14:libpcap-1.5.3-11.el7.x86_64                                                         7/9 
        Installing : mongodb-2.6.12-6.el7.x86_64                                                            8/9 
        Installing : mongodb-server-2.6.12-6.el7.x86_64                                                     9/9 
        Verifying  : mongodb-2.6.12-6.el7.x86_64                                                            1/9 
        Verifying  : libstemmer-0-2.585svn.el7.x86_64                                                       2/9 
        Verifying  : 1:v8-3.14.5.10-25.el7.x86_64                                                           3/9 
        Verifying  : gperftools-libs-2.6.1-1.el7.x86_64                                                     4/9 
        Verifying  : boost-program-options-1.53.0-27.el7.x86_64                                             5/9 
        Verifying  : mongodb-server-2.6.12-6.el7.x86_64                                                     6/9 
        Verifying  : 1:yaml-cpp-0.5.1-1.el7.2.x86_64                                                        7/9 
        Verifying  : boost-filesystem-1.53.0-27.el7.x86_64                                                  8/9 
        Verifying  : 14:libpcap-1.5.3-11.el7.x86_64                                                         9/9 
    
    Installed:
        mongodb.x86_64 0:2.6.12-6.el7                    mongodb-server.x86_64 0:2.6.12-6.el7                   
    
    Dependency Installed:
        boost-filesystem.x86_64 0:1.53.0-27.el7           boost-program-options.x86_64 0:1.53.0-27.el7          
        gperftools-libs.x86_64 0:2.6.1-1.el7              libpcap.x86_64 14:1.5.3-11.el7                        
        libstemmer.x86_64 0:0-2.585svn.el7                v8.x86_64 1:3.14.5.10-25.el7                          
        yaml-cpp.x86_64 1:0.5.1-1.el7.2                  
    
    Complete!
    

    4.3 CentOS系统上操作MongoDB数据库常用命令

    [root@localhost ~]# systemctl status mongod                 # 查看系统上MongoDB数据库启动状态
    ● mongod.service - High-performance, schema-free document-oriented database
        Loaded: loaded (/usr/lib/systemd/system/mongod.service; disabled; vendor preset: disabled)
        Active: inactive (dead)
    [root@localhost ~]# systemctl start mongod                  # 启动MongoDB数据库
    [root@localhost ~]# systemctl status mongod                 # 再次查看MongoDB数据库的启动状态,显示已启动
    ● mongod.service - High-performance, schema-free document-oriented database
        Loaded: loaded (/usr/lib/systemd/system/mongod.service; disabled; vendor preset: disabled)
        Active: active (running) since Mon 2019-03-18 19:22:17 CST; 2s ago
        Process: 1393 ExecStart=/usr/bin/mongod $OPTIONS run (code=exited, status=0/SUCCESS)
        Main PID: 1395 (mongod)
        CGroup: /system.slice/mongod.service
                └─1395 /usr/bin/mongod --quiet -f /etc/mongod.conf run
    
    Mar 18 19:22:17 localhost.localdomain systemd[1]: Starting High-performance, schema-free document-or......
    Mar 18 19:22:17 localhost.localdomain mongod[1393]: about to fork child process, waiting until serve...ns.
    Mar 18 19:22:17 localhost.localdomain mongod[1393]: forked process: 1395
    Mar 18 19:22:17 localhost.localdomain systemd[1]: Started High-performance, schema-free document-ori...se.
    Hint: Some lines were ellipsized, use -l to show in full.
    [root@localhost ~]# systemctl stop mongod                   # 停止MongoDB
    [root@localhost ~]# systemctl status mongod
    ● mongod.service - High-performance, schema-free document-oriented database
        Loaded: loaded (/usr/lib/systemd/system/mongod.service; disabled; vendor preset: disabled)
        Active: inactive (dead)
    
    Mar 18 19:22:17 localhost.localdomain systemd[1]: Starting High-performance, schema-free document-or......
    Mar 18 19:22:17 localhost.localdomain mongod[1393]: about to fork child process, waiting until serve...ns.
    Mar 18 19:22:17 localhost.localdomain mongod[1393]: forked process: 1395
    Mar 18 19:22:17 localhost.localdomain systemd[1]: Started High-performance, schema-free document-ori...se.
    Mar 18 19:22:23 localhost.localdomain systemd[1]: Stopping High-performance, schema-free document-or......
    Mar 18 19:22:23 localhost.localdomain systemd[1]: Stopped High-performance, schema-free document-ori...se.
    Hint: Some lines were ellipsized, use -l to show in full.
    [root@localhost ~]# systemctl enable mongod                 # 把MongoDB设置为开机自启动
    Created symlink from /etc/systemd/system/multi-user.target.wants/mongod.service to /usr/lib/systemd/system/mongod.service.
    [root@localhost ~]# systemctl disable mongod                # 取消MongoDB数据库开机自启动
    Removed symlink /etc/systemd/system/multi-user.target.wants/mongod.service.
    

    5.MongoDB的基础命令

    数据库基本操作:

    show dbs/show databases             # 查看所有数据库
    use db_name                         # 切换数据库
    db                                  # 查看当前数据库
    db.dropDatabase()                   # 删除当前数据库
    

    命令的基本操作:

    db.createCollection(name,options)   # 手动创建集合
        options可配置选项为:
            capped:默认值为false表示集合大小不设置上限,值为true表示为集合大小设置上限
            size:当capped值为true时,需要指定参数,表示集合上限大小,当文档达到上限时,会将之前的数据覆盖,单位为字节
    show collections                    # 查看所有集合
    db.集合名称.drop()                   # 删除指定集合
    

    向不存在的集合中第一次加入数据时,集合会自动被创建出来,也可以手动创建集合

    示例:

    [root@localhost ~]# mongo
    MongoDB shell version v3.4.16
    connecting to: mongodb://127.0.0.1:27017
    MongoDB server version: 3.4.16
    Server has startup warnings: 
    2019-03-21T21:38:26.752+0800 I CONTROL  [initandlisten] 
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] 
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] 
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] 
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
    2019-03-21T21:38:26.753+0800 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
    2019-03-21T21:38:26.754+0800 I CONTROL  [initandlisten] 
    > show dbs                                  # 查看所有数据库
    admin   0.000GB
    local   0.000GB
    quotes  0.000GB
    > db.createCollection("study_test")         # 手动创建study_test集合,返回1表示集合创建成功
    { "ok" : 1 }
    > use study_test                            # 使用study_test集合
    switched to db study_test
    

    6.MongoDB的数据类型

    MongoDB中的数据类型有:

    Object ID                   # 文档ID
    String                      # 字符串,最常用,必须是有效的UTF-8
    Boolean                     # 存储一个布尔值,true或false
    Integer                     # 整数可以是32位或者64位,取决于服务器
    Double                      # 存储浮点值
    Arrays                      # 数组或列表,多个值存储到一个键
    Object                      # 用于嵌入式的文档,即一个值为一个文档
    Null                        # 存储Null值
    Timestamp                   # 时间戳,表示从1970-1-1到现在的总秒数
    Date                        # 存储当前日期或时间的UNIX时间格式
    

    需要注意的点:

    1.创建⽇期语句如下 :参数的格式为YYYY-MM-DD

    例如:

    > new Date("2018-12-12")
    ISODate("2018-12-12T00:00:00Z")
    

    2.每个⽂档都有⼀个_id属性,保证每个⽂档的唯⼀性.在向集合中写入文档时,可以⾃⼰设置文档的_id属性,如果没有手动指定,则MongoDB会为每个⽂档提供了⼀个唯一的_id, 类型为objectID

    objectID是⼀个12字节的⼗六进制数:前4个字节为当前时间戳,接下来3个字节的机器ID,接下来的2个字节中MongoDB的服务进程id,最后3个字节是简单的增量值

    例如:

    > db.test_table01.insert({"name":"xiaowang","age":10})          # 向test_table01集合中插入一条数据
    WriteResult({ "nInserted" : 1 })
    > db.test_table01.find()                    # 打印test_table01中的所有数据
    { "_id" : ObjectId("5c939a4f4c9ce97c5b78a0da"), "name" : "xiaowang", "age" : 10 }
    > db.test_table01.find().pretty()           # 格式化打印test_table01中的所有数据
    {
            "_id" : ObjectId("5c939a4f4c9ce97c5b78a0da"),
            "name" : "xiaowang",
            "age" : 10
    }
    > db.test_table01.insert({name:"xiaohong",age:20})
    WriteResult({ "nInserted" : 1 })
    > db.test_table01.find()
    { "_id" : ObjectId("5c939a4f4c9ce97c5b78a0da"), "name" : "xiaowang", "age" : 10 }
    { "_id" : ObjectId("5c939adc4c9ce97c5b78a0db"), "name" : "xiaohong", "age" : 20 }
    > db.test_table01.find().pretty()
    {
            "_id" : ObjectId("5c939a4f4c9ce97c5b78a0da"),
            "name" : "xiaowang",
            "age" : 10
    }
    {
            "_id" : ObjectId("5c939adc4c9ce97c5b78a0db"),
            "name" : "xiaohong",
            "age" : 20
    }
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  • 原文地址:https://www.cnblogs.com/renpingsheng/p/10576805.html
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