MongoDB基本操作
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1. 进入mongo环境
mongo
[[email protected] ~]# 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:
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten]
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten]
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten]
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is ‘always‘.
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten] ** We suggest setting it to ‘never‘
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten]
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is ‘always‘.
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten] ** We suggest setting it to ‘never‘
2018-07-20T17:53:38.109+0800 I CONTROL [initandlisten]
> 2.查询所有数据库
show dbs;
> show dbs
admin 0.000GB
local 0.000GB
3.创建或者切换库（如果数据库不存在，则创建数据库，否则切换到指定数据库）
use mydb；
> use mydb
switched to db mydb
> show dbs
admin 0.000GB
local 0.000GB
可以看到，我们刚创建的数据库 mydb并不在数据库的列表中， 要显示它，我们需要向 mydb数据库插入一些数据。
4.创建集合
> db.createCollection("log")
{ "ok" : 1 }
> show dbs
admin 0.000GB
local 0.000GB
mydb 0.000GB
5. 插入数据 （如果插入时集合不存在，则包括创建集合和插入数据两个动作）及更新
> db.logdata.insert({name:‘zhangsan‘, age:‘25‘});
WriteResult({ "nInserted" : 1 }
> db.logdata.insert({‘_id‘: ‘terrywang‘, ‘super_admin‘: true})
WriteResult({ "nInserted" : 1 })
> db.logdata.find({‘_id‘:‘terrywang‘})
{ "_id" : "terrywang", "super_admin" : true } > db.logdata.update({‘_id‘: ‘terrywang‘}, {$set: {‘super_admin‘: false}})
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.logdata.find({"_id":"terrywang"})
{ "_id" : "terrywang", "super_admin" : false }
6.查看集合内容
> db.logdata.find()
{ "_id" : ObjectId("5b529ef8bfde59a50f5e5397"), "name" : "lisi", "age" : "30" }
{ "_id" : "terrywang", "super_admin" : false }
> db.logdata.findOne({‘_id‘:‘terrywang‘})
{ "_id" : "terrywang", "super_admin" : true } 7.按条件筛选
> db.logdata.find({"name":"zhangsan"});
{ "_id" : ObjectId("5b529e14bfde59a50f5e5396"), "name" : "zhangsan", "age" : "25" }
正则查找
> db.logdata.find({"_id":/e*/i})
{ "_id" : "terrywang", "super_admin" : false }
i表明是否是case-insensitive，有i则表示忽略大小写
只筛选到某一列
> db.logdata.find({},{D:1})
{ "_id" : ObjectId("5b529ad3aea13d710cc622d5") } 8.删除文档
先插入一个文档
> db.logdata.insert({name:‘lisi‘, age:‘30‘});
WriteResult({ "nInserted" : 1 })
> db.logdata.find()
{ "_id" : ObjectId("5b529e14bfde59a50f5e5396"), "name" : "zhangsan", "age" : "25" }
{ "_id" : ObjectId("5b529ef8bfde59a50f5e5397"), "name" : "lisi", "age" : "30" }
删除一个文档
> db.logdata.remove({"name":"zhangsan"})
WriteResult({ "nRemoved" : 1 })
> db.logdata.find()
{ "_id" : ObjectId("5b529ef8bfde59a50f5e5397"), "name" : "lisi", "age" : "30" }
9.显示集合
> show tables;
log
logdata
10.显示集合中文档数
> db.logdata.find()
{ "_id" : ObjectId("5b529ef8bfde59a50f5e5397"), "name" : "lisi", "age" : "30" }
{ "_id" : "terrywang", "super_admin" : false }
> db.logdata.count()
2
11.查看集合索引
> db.logdata.getIndex()
2018-07-21T11:42:09.337+0800 E QUERY [thread1] TypeError: db.logdata.getIndex is not a function :
@(shell):1:1
> db.logdata.getIndexes()
[
{
"v" : 2,
"key" : {
"_id" : 1
},
"name" : "_id_",
"ns" : "mydb.logdata"
}
]
12.删除表
> db.logdata.drop()
true
> show tables;
log
test
> db.test.drop()
true
> show tables
log
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