mongoDB安装及CRUD操作

深碍√TFBOYSˉ_ 2022-09-25 05:16 180阅读 0赞

**一、mongodb简介**  
[http://www.ttlsa.com/mongodb/nosql-mongodb-description/][http_www.ttlsa.com_mongodb_nosql-mongodb-description]  
MongoDB组成部分：

1.  Database：可以有多个数据库，各个数据库间相互独立，每个数据库作为一个容器可以包含一个或多个集合(collection)。
2.  Collection：集合是一组文档(document)。在逻辑上相当于关系型数据库中的表。但是与表不同的是，在向集合存储数据时无需事先定义数据结构。
3.  Document：集合中存储文档的单位。一个文档包含了一系列字段或键值对。键是字符串，值可以是各种类型：字符串，整数，浮点数，时间戳，布尔值等等，甚至可以存储另一个文档，以json格式存储。

MongoDB数据交换格式：

*  文档的结构是一个JSON对象。当将这个文档存储于数据库中，将被序列化成一个特殊的二进制编码格式，成为BSON。
 *  BSON是MongoDB默认的数据交换格式。与XML和JSON相比BSON的优势在于内存的消耗和处理时间上更高效。JSON支持BSON支持的所有数据类型，同时还支持一些特殊的数据类型，比如正则表达式，对象ID，日期，二进制数据和代码。更好的移植性，编程语言如PHP，PYTHON，JAVA等等可以直接从BSON格式进行转换，易于与MongoDB融合和管理维护数据。

MongoDB与RDMS对比：

<table> 
 <thead> 
  <tr> 
   <th>RDMS</th> 
   <th align="left">database</th> 
   <th align="left">table</th> 
   <th align="left">row</th> 
   <th align="left">column</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>MongoDB</td> 
   <td align="left">database</td> 
   <td align="left">collection</td> 
   <td align="left">document</td> 
   <td align="left">field</td> 
  </tr> 
 </tbody> 
</table>

MongoDB集合中没有外键，没有联合查询，约束性管理通常由应用层处理。因此其架构很灵活，也没有昂贵的alter table操作。

**二、mongodb安装**  
官网下载最新版本  
[https://www.mongodb.com/download-center?jmp=nav\#community][https_www.mongodb.com_download-center_jmp_nav_community]  
[https://docs.mongodb.com/master/tutorial/install-mongodb-on-red-hat/][https_docs.mongodb.com_master_tutorial_install-mongodb-on-red-hat]  
1、配置好yum源后进行安装

# vim /etc/yum.repos.d/mongodb-org-3.2.repo
    [mongodb-org-3.2]
    name=MongoDB Repository
    baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.2/x86_64/
    gpgcheck=0
    enabled=1
    gpgkey=https://www.mongodb.org/static/pgp/server-3.2.asc
    # yum install -y mongodb-org
    # rpm -qa |grep mongodb 
    mongodb-org-mongos-3.2.8-1.el7.x86_64
    mongodb-org-server-3.2.8-1.el7.x86_64
    mongodb-org-shell-3.2.8-1.el7.x86_64
    mongodb-org-3.2.8-1.el7.x86_64
    mongodb-org-tools-3.2.8-1.el7.x86_64

bsondump:

2、工具介绍  
[https://docs.mongodb.com/manual/reference/program/mongooplog/][https_docs.mongodb.com_manual_reference_program_mongooplog]  
[https://docs.mongodb.com/manual/reference/program/mongoperf/][https_docs.mongodb.com_manual_reference_program_mongoperf]

# rpm -ql mongodb-org-mongos |grep bin
    /usr/bin/mongos      ##分片路由，如果使用了sharding功能，则应用程序连接的是mongos而不是mongod
    # rpm -ql mongodb-org-server |grep bin
    /usr/bin/mongod      ##数据库服务端，每个实例启动一个进程，可以fork为后台运行
    # rpm -ql mongodb-org-shell |grep bin
    /usr/bin/mongo       ##客户端命令行工具，其实也是一个javascript解释器，支持javascript语法
    # rpm -ql mongodb-org-tools |grep bin
    /usr/bin/bsondump       ##将bson格式的文件转储为json格式的数据
    /usr/bin/mongodump      ##数据库备份
    /usr/bin/mongoexport    ##数据导出
    /usr/bin/mongofiles     ##GridFS管理，可实现二制文件的存取
    /usr/bin/mongoimport    ##数据导入
    /usr/bin/mongooplog     ##从远程服务器的复制oplog中检查操作,并应用于本地服务器
    /usr/bin/mongoperf      ##测试磁盘I/O性能，可做mongo的I/O压力测试
    /usr/bin/mongorestore   ##数据恢复
    /usr/bin/mongostat      ##实时性能监控
    /usr/bin/mongotop       ##跟踪MongoDB的实例， 提供每个集合的统计数据。默认情况下，mongotop每一秒刷新一次

2、修改配置文件，创建数据库目录，启动服务

# cat /etc/mongod.conf |grep dbPath
      dbPath: /mongodb/data
    # mkdir -pv /mongodb/data ##默认不会自动创建数据库目录
    mkdir: created directory ‘/mongodb’
    mkdir: created directory ‘/mongodb/data’
    # chown -R mongod.mongod /mongodb/data
    # service mongod start
    Starting mongod (via systemctl):                           [  OK  ]

**三、mongoDB的CRUD操作**  
[http://www.ttlsa.com/mongodb/mongodb-insert-delete-select-update/][http_www.ttlsa.com_mongodb_mongodb-insert-delete-select-update]

*  **select VS db.coll.find()**

![这里写图片描述][20160815124110001]

*  **insert operation**

![这里写图片描述][20160815124007153]

*  **update VS db.coll.update()**

![这里写图片描述][20160815124028750]

*  **delete VS db.coll.delete()**

![这里写图片描述][20160815124049903]  
1、使用客户端命令连接到本机数据库，插入测试数据

# mongo
    > help        ##查看可以使用的命令
    > db.help()   ##获取数据库相关操作的方法
    > for(i=1;i<100;i++) db.testcoll.insert({name:"user"+i,age:i,gender:"f",prefruits:["peach","strawberry"]})
    WriteResult({ "nInserted" : 1 })
    > show collections;
    testcoll

2、删除年龄为3和姓名为user8的用户，并更新user7的年龄为77，查询testcoll中前7项文档

> db.testcoll.remove({age:3})
    WriteResult({ "nRemoved" : 1 })
    > db.testcoll.remove({name:"user8"})
    WriteResult({ "nRemoved" : 1 })
    > db.testcoll.update({name:"user7"},{$set:{age:77}})
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.testcoll.find().limit(7)
    { "_id" : ObjectId("57b0038c871b1423b53cdbc2"), "name" : "user1", "age" : 1, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdbc3"), "name" : "user2", "age" : 2, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdbc5"), "name" : "user4", "age" : 4, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdbc6"), "name" : "user5", "age" : 5, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdbc7"), "name" : "user6", "age" : 6, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdbc8"), "name" : "user7", "age" : 77, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdbca"), "name" : "user9", "age" : 9, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }

3、查询年龄>=15，<=17的文档

> db.testcoll.find({
       $and:[{age:{
       $gte:15}},{age:{
       $lte:17}}]})
    { "_id" : ObjectId("57b0038c871b1423b53cdbd0"), "name" : "user15", "age" : 15, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdbd1"), "name" : "user16", "age" : 16, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdbd2"), "name" : "user17", "age" : 17, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }

4、查询包含某元素的文档

> db.testcoll.insert({name:"Celeste",age:22,gender:"m",fruit:["avocado","mangosteen"]})
    WriteResult({ "nInserted" : 1 })
    > db.testcoll.find({fruit:{$exists:true}})
    { "_id" : ObjectId("57b00a81871b1423b53cdc26"), "name" : "Celeste", "age" : 22, "gender" : "m", "fruit" : [ "avocado", "mangosteen" ] }

5、更新文档，mongoDB默认情况下只修改匹配到的第一个符合条件的文档指定multi为true

> db.testcoll.update({age:{$gt:95}},{$set:{gender:"m"}})
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.testcoll.find({age:{$gt:95}})
    { "_id" : ObjectId("57b0038c871b1423b53cdc21"), "name" : "user96", "age" : 96, "gender" : "m", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdc22"), "name" : "user97", "age" : 97, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdc23"), "name" : "user98", "age" : 98, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdc24"), "name" : "user99", "age" : 99, "gender" : "f", "prefruits" : [ "peach", "strawberry" ] }
    > db.testcoll.update({age:{$gt:95}},{$set:{gender:"m"}},{multi:true})
    WriteResult({ "nMatched" : 4, "nUpserted" : 0, "nModified" : 3 })
    > db.testcoll.find({age:{$gt:95}})
    { "_id" : ObjectId("57b0038c871b1423b53cdc21"), "name" : "user96", "age" : 96, "gender" : "m", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdc22"), "name" : "user97", "age" : 97, "gender" : "m", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdc23"), "name" : "user98", "age" : 98, "gender" : "m", "prefruits" : [ "peach", "strawberry" ] }
    { "_id" : ObjectId("57b0038c871b1423b53cdc24"), "name" : "user99", "age" : 99, "gender" : "m", "prefruits" : [ "peach", "strawberry" ] }

6、更新文档删除指定字段

> db.testcoll.update({name:"user98"},{$unset:{gender:""}})
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.testcoll.find({age:{$in:[98]}})
    { "_id" : ObjectId("57b0038c871b1423b53cdc23"), "name" : "user98", "age" : 98, "prefruits" : [ "peach", "strawberry" ] }

7、查询连接数

> db.serverStatus().connections
    { "current" : 1, "available" : 52427, "totalCreated" : NumberLong(6) }

[http_www.ttlsa.com_mongodb_nosql-mongodb-description]: http://www.ttlsa.com/mongodb/nosql-mongodb-description/
[https_www.mongodb.com_download-center_jmp_nav_community]: https://www.mongodb.com/download-center?jmp=nav#community
[https_docs.mongodb.com_master_tutorial_install-mongodb-on-red-hat]: https://docs.mongodb.com/master/tutorial/install-mongodb-on-red-hat/
[https_docs.mongodb.com_manual_reference_program_mongooplog]: https://docs.mongodb.com/manual/reference/program/mongooplog/
[https_docs.mongodb.com_manual_reference_program_mongoperf]: https://docs.mongodb.com/manual/reference/program/mongoperf/
[http_www.ttlsa.com_mongodb_mongodb-insert-delete-select-update]: http://www.ttlsa.com/mongodb/mongodb-insert-delete-select-update/
[20160815124110001]: /images/20220718/6b60027f40c44846b3a4a68aca1f55b2.png
[20160815124007153]: /images/20220718/6c2e553b0b024aab9ec4ad3f9346049d.png
[20160815124028750]: /images/20220718/34fcff2bad4d4daa82d59a7569a2de9a.png
[20160815124049903]: /images/20220718/52690fc9284d431fa37cfeb920d2550b.png