目标：

安装mongo数据库及常用命令。

准备：

-centos7
-网络

安装mongodb：

[root@node1 ~]# yum -y install centos-release-openstack-pike
[root@node1 ~]# yum -y install mongodb mongodb-server      

修改配置文件：

/etc/mongod.conf下
删除：bind_ip = 127.0.0.1
修改：smallfiles = true

启动：

[root@node1 ~]# systemctl start mongod.service

登录：
数据库端口：27017

[root@node1 ~]# mongo 127.0.0.1:27017
MongoDB shell version: 2.6.11
connecting to: 127.0.0.1:27017/test
Server has startup warnings: 
2019-05-24T17:41:25.977+0000 [initandlisten] 
2019-05-24T17:41:25.977+0000 [initandlisten] ** WARNING: Readahead for /var/lib/mongodb is set to 4096KB
2019-05-24T17:41:25.977+0000 [initandlisten] **          We suggest setting it to 256KB (512 sectors) or less
2019-05-24T17:41:25.977+0000 [initandlisten] **          http://dochub.mongodb.org/core/readahead
>

安装完成

常用命令：

use 库名，如果没有这个数据库则创建：

> use test;  
switched to db test

查看数据库列表：

> show dbs;  
admin  (empty)
local  0.031GB
test   0.031GB

向test_collection集合中插入数据，如果没有这个集合则创建：

> db.test_collection.insert({"id":"1","name":"XiaoMing"});  
WriteResult({ "nInserted" : 1 })

查看test数据库下的集合列表：

> show collections;  
system.indexes
test_collection

批量插入，变量“i”作为“id”：

> for(i=1;i<=100;i++) db.test_collection.insert({"id":i,"name":"test"});  
WriteResult({ "nInserted" : 1 })

统计查询结果数：

> db.collection.find().count(); 
30

批量修改，每条数据的年龄=18+id，test=6+id：

> for(i=1;i<=30;i++) db.collection.update({"id":i},{"id":i,"name":"test","age":18+i,"test":6+i});  
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

查询test_collection集合下所有数据：

> db.test_collection.find(); 
{ "_id" : ObjectId("5ce82da287c20cb0e031cb1d"), "id" : "1", "name" : "XiaoMing" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb1e"), "id" : 1, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb1f"), "id" : 2, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb20"), "id" : 3, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb21"), "id" : 4, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb22"), "id" : 5, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb23"), "id" : 6, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb24"), "id" : 7, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb25"), "id" : 8, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb26"), "id" : 9, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb27"), "id" : 10, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb28"), "id" : 11, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb29"), "id" : 12, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb2a"), "id" : 13, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb2b"), "id" : 14, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb2c"), "id" : 15, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb2d"), "id" : 16, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb2e"), "id" : 17, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb2f"), "id" : 18, "name" : "test" }
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb30"), "id" : 19, "name" : "test" }
Type "it" for more

查询“id”为“1”的行：

> db.test_collection.find({"id":"1"});  
{ "_id" : ObjectId("5ce82da287c20cb0e031cb1d"), "id" : "1", "name" : "XiaoMing" }

查询“id”为1的行：

> db.test_collection.find({"id":1});    
{ "_id" : ObjectId("5ce82e4f87c20cb0e031cb1e"), "id" : 1, "name" : "test" }

删除“id”为“1”的行：

> db.test_collection.remove({"id":"1"});  
WriteResult({ "nRemoved" : 1 })

删除集合：

> db.test_collection.drop(); 
true

删除当前数据库：

> db.dropDatabase();  
{ "dropped" : "test", "ok" : 1 }

删除重复数据：
根据唯一的“_id”列来删除

> db.collection.find();
{ "_id" : ObjectId("5ce83107506da8e173b59c56"), "id" : 1, "name" : "test" }
{ "_id" : ObjectId("5ce83119506da8e173b59c57"), "id" : 1, "name" : "test" }
> db.collection.remove({"_id" : ObjectId("5ce83107506da8e173b59c56")}); 
WriteResult({ "nRemoved" : 1 })

修改“id“为1的行：

> db.collection.update({"id":1},{"id":10,"name":"update"}); 
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.collection.find();
{ "_id" : ObjectId("5ce83119506da8e173b59c57"), "id" : 10, "name" : "update" }

查询”id“小于15、”age“大于等于25和”test“在15和20之间的行：

> db.collection.find({"id":{$lt:15},"age":{$gte:25},"test":{$lte:20,$gte:15}});
{ "_id" : ObjectId("5ce834ae506da8e173b59cd8"), "id" : 9, "name" : "test", "age" : 27, "test" : 15 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cd9"), "id" : 10, "name" : "test", "age" : 28, "test" : 16 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cda"), "id" : 11, "name" : "test", "age" : 29, "test" : 17 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdb"), "id" : 12, "name" : "test", "age" : 30, "test" : 18 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdc"), "id" : 13, "name" : "test", "age" : 31, "test" : 19 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdd"), "id" : 14, "name" : "test", "age" : 32, "test" : 20 }

显示查询结果的前两行：

> db.collection.find({"id":{$lt:15},"age":{$gte:25},"test":{$lte:20,$gte:15}}).limit(2); 
{ "_id" : ObjectId("5ce834ae506da8e173b59cd8"), "id" : 9, "name" : "test", "age" : 27, "test" : 15 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cd9"), "id" : 10, "name" : "test", "age" : 28, "test" : 16 }

跳过查询结果的前两行:

> db.collection.find({"id":{$lt:15},"age":{$gte:25},"test":{$lte:20,$gte:15}}).skip(2);  
{ "_id" : ObjectId("5ce834ae506da8e173b59cda"), "id" : 11, "name" : "test", "age" : 29, "test" : 17 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdb"), "id" : 12, "name" : "test", "age" : 30, "test" : 18 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdc"), "id" : 13, "name" : "test", "age" : 31, "test" : 19 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdd"), "id" : 14, "name" : "test", "age" : 32, "test" : 20 }

以”id“的值降序排列：

> db.collection.find({"id":{$lt:15},"age":{$gte:25},"test":{$lte:20,$gte:15}}).sort({id:-1});  
{ "_id" : ObjectId("5ce834ae506da8e173b59cdd"), "id" : 14, "name" : "test", "age" : 32, "test" : 20 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdc"), "id" : 13, "name" : "test", "age" : 31, "test" : 19 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdb"), "id" : 12, "name" : "test", "age" : 30, "test" : 18 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cda"), "id" : 11, "name" : "test", "age" : 29, "test" : 17 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cd9"), "id" : 10, "name" : "test", "age" : 28, "test" : 16 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cd8"), "id" : 9, "name" : "test", "age" : 27, "test" : 15 }

以”age“的值升序排列：

> db.collection.find({"id":{$lt:15},"age":{$gte:25},"test":{$lte:20,$gte:15}}).sort({age:1});  
{ "_id" : ObjectId("5ce834ae506da8e173b59cd8"), "id" : 9, "name" : "test", "age" : 27, "test" : 15 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cd9"), "id" : 10, "name" : "test", "age" : 28, "test" : 16 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cda"), "id" : 11, "name" : "test", "age" : 29, "test" : 17 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdb"), "id" : 12, "name" : "test", "age" : 30, "test" : 18 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdc"), "id" : 13, "name" : "test", "age" : 31, "test" : 19 }
{ "_id" : ObjectId("5ce834ae506da8e173b59cdd"), "id" : 14, "name" : "test", "age" : 32, "test" : 20 }

cs