1.mongodb入門命令

1.1 show databases; 或 show dbs; //查看當前的數據庫

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

1.2 use databaseName  選擇庫

      show tables/collections 查看當前庫下的collections

1.3 如何創建庫

　　mongodb 的庫是隱式創建，你可以use一個不存在的庫

　　然后在該庫下創建collection，即可創建庫

1.4 db.createCollection('collectionName');  //創建collection

1.5 collection 允許隱式創建

　  db.collectionName.insert(document);

1.6 db.collectionName.drop();       /刪除collection

> use shop
switched to db shop
> db.createCollection('user');
{ "ok" : 1 }
> show dbs;
admin   0.000GB
config  0.000GB
local   0.000GB
shop    0.000GB
> show collections;
user

1.7插入user表語句

(1)自動生成id值

 db.user.insert({name:'lisi',age:22})
WriteResult({ "nInserted" : 1 })
> db.user.find();
{ "_id" : ObjectId("5d73077c71b815674de4d152"), "name" : "lisi", "age" : 22 }

(2) 指定生成id

> db.user.insert({_id:2,name:'wangwu',age:25})
WriteResult({ "nInserted" : 1 })
> db.user.find();
{ "_id" : ObjectId("5d73077c71b815674de4d152"), "name" : "lisi", "age" : 22 }
{ "_id" : 2, "name" : "wangwu", "age" : 25 }

(3) 插入多層

> db.user.insert({_id:3,name:'xiaobing',hobby:['basketball','football'],intro:{'title':'My intro','content':'from china'}});
WriteResult({ "nInserted" : 1 })
> db.user.find();
{ "_id" : ObjectId("5d73077c71b815674de4d152"), "name" : "lisi", "age" : 22 }
{ "_id" : 2, "name" : "wangwu", "age" : 25 }
{ "_id" : 3, "name" : "xiaobing", "hobby" : [ "basketball", "football" ], "intro" : { "title" : "My intro", "content" : "from china" } }
>

 1.8 其實mongodb不需要聲明表,可直接寫入表數據,即可創建成功!

> show tables;
user
> db.goods.insert({_id:1,name:'oppoR11',price:'3000'});
WriteResult({ "nInserted" : 1 })
> show tables;
goods
user
> db.goods.find()
{ "_id" : 1, "name" : "oppoR11", "price" : "3000" }

1.9 刪除表 db.collectionName.drop();

> show collections
goods
user
> db.goods.drop();
true
> show collections;
user
>                   

2.0 刪除數據庫

 db.dropDatabase()

> show dbs;
admin   0.000GB
config  0.000GB
local   0.000GB
shop    0.000GB
> use shop;
switched to db shop

> db.dropDatabase();
{ "dropped" : "shop", "ok" : 1 }
> show dbs;
admin   0.000GB
config  0.000GB
local   0.000GB
>               

2.1 查詢幫助 db.help();

> db.help()
DB methods:
        db.adminCommand(nameOrDocument) - switches to 'admin' db, and runs command [just calls db.runCommand(...)]
        db.aggregate([pipeline], {options}) - performs a collectionless aggregation on this database; returns a cursor
        db.auth(username, password)
        db.cloneDatabase(fromhost) - deprecated
        db.commandHelp(name) returns the help for the command
        db.copyDatabase(fromdb, todb, fromhost) - deprecated
        db.createCollection(name, {size: ..., capped: ..., max: ...})
        db.createView(name, viewOn, [{$operator: {...}}, ...], {viewOptions})
        db.createUser(userDocument)
        db.currentOp() displays currently executing operations in the db
        db.dropDatabase()
        db.eval() - deprecated
        db.fsyncLock() flush data to disk and lock server for backups
        db.fsyncUnlock() unlocks server following a db.fsyncLock()
        db.getCollection(cname) same as db['cname'] or db.cname
        db.getCollectionInfos([filter]) - returns a list that contains the names and options of the db's collections
        db.getCollectionNames()
        db.getLastError() - just returns the err msg string
        db.getLastErrorObj() - return full status object
        db.getLogComponents()
        db.getMongo() get the server connection object
        db.getMongo().setSlaveOk() allow queries on a replication slave server
        db.getName()
        db.getPrevError()
        db.getProfilingLevel() - deprecated
        db.getProfilingStatus() - returns if profiling is on and slow threshold
        db.getReplicationInfo()
        db.getSiblingDB(name) get the db at the same server as this one
        db.getWriteConcern() - returns the write concern used for any operations on this db, inherited from server object if set
        db.hostInfo() get details about the server's host
        db.isMaster() check replica primary status
        db.killOp(opid) kills the current operation in the db
        db.listCommands() lists all the db commands
        db.loadServerScripts() loads all the scripts in db.system.js
        db.logout()
        db.printCollectionStats()
        db.printReplicationInfo()
        db.printShardingStatus()
        db.printSlaveReplicationInfo()
        db.dropUser(username)
        db.repairDatabase()
        db.resetError()
        db.runCommand(cmdObj) run a database command.  if cmdObj is a string, turns it into {cmdObj: 1}
        db.serverStatus()
        db.setLogLevel(level,<component>)
        db.setProfilingLevel(level,slowms) 0=off 1=slow 2=all
        db.setWriteConcern(<write concern doc>) - sets the write concern for writes to the db
        db.unsetWriteConcern(<write concern doc>) - unsets the write concern for writes to the db
        db.setVerboseShell(flag) display extra information in shell output
        db.shutdownServer()
        db.stats()
        db.version() current version of the server