MongoDB 常用命令介绍
在安装MongoDB后，启动服务器进程（mongod），可以通过在客户端命令mongo实现对MongoDB的管理和监控。看一下MongoDB的命令帮助系统。
一、客户端命令：mongo
#./bin/mongo -h
MongoDB shell version: 2.6.8
usage: ./bin/mongo [options] [db address] [file names (ending in .js)]
db address can be:
foo foo database on local machine
192.169.0.5/foo foo database on 192.168.0.5 machine
192.169.0.5:9999/foo foo database on 192.168.0.5 machine on port 9999
Options:
--shell run the shell after executing files
--nodb don't connect to mongod on startup - no
'db address' arg expected
--norc will not run the ".mongorc.js" file on
start up
--quiet be less chatty
--port arg port to connect to
--host arg server to connect to
--eval arg evaluate javascript
-h [ --help ] show this usage information
--version show version information
--verbose increase verbosity
--ipv6 enable IPv6 support (disabled by
default)
Authentication Options:
-u [ --username ] arg username for authentication
-p [ --password ] arg password for authentication
--authenticationDatabase arg user source (defaults to dbname)
--authenticationMechanism arg (=MONGODB-CR)
authentication mechanism
--gssapiServiceName arg (=mongodb) Service name to use when authenticating
using GSSAPI/Kerberos
--gssapiHostName arg Remote host name to use for purpose of
GSSAPI/Kerberos authentication
file names: a list of files to run. files have to end in .js and will exit after unless --shell is specified如上可以指定IP、端口、数据库及认证信息（用户名、密码）等连接mongodb数据库。
二、MongoDB最顶层的命令
通过mongo进入数据库，使用help查看MongoDB最顶层的命令列表，主要告诉我们管理数据库相关的一些抽象的范畴：数据库操作帮助、集合操作帮助、管理帮助。
> helphelp
db.help() help on db methods
db.mycoll.help() help on collection methods
sh.help() sharding helpers
rs.help() replica set helpers
help admin administrative help
help connect connecting to a db help
help keys key shortcuts
help misc misc things to know
help mr mapreduce
show dbs show database names
show collections show collections in current database
show users show users in current database
show profile show most recent system.profile entries with time >= 1ms
show logs show the accessible logger names
show log [name] prints out the last segment of log in memory, 'global' is default
use <db_name> set current database
db.foo.find() list objects in collection foo
db.foo.find( { a : 1 } ) list objects in foo where a == 1
it result of the last line evaluated; use to further iterate
DBQuery.shellBatchSize = x set default number of items to display on shell
exit quit the mongo shell如果你想了解数据库操作更详细的帮助命令，可以直接使用db.help():
> db.help();
DB methods:
db.adminCommand(nameOrDocument) - switches to 'admin' db, and runs command [ just calls db.runCommand(...) ]
db.auth(username, password)
db.cloneDatabase(fromhost)
db.commandHelp(name) returns the help for the command
db.copyDatabase(fromdb, todb, fromhost)
db.createCollection(name, { size : ..., capped : ..., max : ... } )
db.createUser(userDocument)
db.currentOp() displays currently executing operations in the db
db.dropDatabase()
db.eval(func, args) run code server-side
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()
db.getCollectionNames()
db.getLastError() - just returns the err msg string
db.getLastErrorObj() - return full status object
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.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对数据库进行管理和操作的基本命令，可以从上面获取到。如果想要得到更多，而且每个命令的详细用法，可以使用上面列出的db.listCommands()查询。另一个比较基础的是对指定数据库的集合进行操作、管理和监控，可以通过查询db.mycoll.help()获取到：
> db.mycoll.help();
DBCollection help
db.mycoll.find().help() - show DBCursor help
db.mycoll.count()
db.mycoll.copyTo(newColl) - duplicates collection by copying all documents to newColl; no indexes are copied.
db.mycoll.convertToCapped(maxBytes) - calls {convertToCapped:'mycoll', size:maxBytes}} command
db.mycoll.dataSize()
db.mycoll.distinct( key ) - e.g. db.mycoll.distinct( 'x' )
db.mycoll.drop() drop the collection
db.mycoll.dropIndex(index) - e.g. db.mycoll.dropIndex( "indexName" ) or db.mycoll.dropIndex( { "indexKey" : 1 } )
db.mycoll.dropIndexes()
db.mycoll.ensureIndex(keypattern[,options]) - options is an object with these possible fields: name, unique, dropDups
db.mycoll.reIndex()
db.mycoll.find([query],[fields]) - query is an optional query filter. fields is optional set of fields to return.
e.g. db.mycoll.find( {x:77} , {name:1, x:1} )
db.mycoll.find(...).count()
db.mycoll.find(...).limit(n)
db.mycoll.find(...).skip(n)
db.mycoll.find(...).sort(...)
db.mycoll.findOne([query])
db.mycoll.findAndModify( { update : ... , remove : bool [, query: {}, sort: {}, 'new': false] } )
db.mycoll.getDB() get DB object associated with collection
db.mycoll.getPlanCache() get query plan cache associated with collection
db.mycoll.getIndexes()
db.mycoll.group( { key : ..., initial: ..., reduce : ...[, cond: ...] } )
db.mycoll.insert(obj)
db.mycoll.mapReduce( mapFunction , reduceFunction , <optional params> )
db.mycoll.aggregate( [pipeline], <optional params> ) - performs an aggregation on a collection; returns a cursor
db.mycoll.remove(query)
db.mycoll.renameCollection( newName , <dropTarget> ) renames the collection.
db.mycoll.runCommand( name , <options> ) runs a db command with the given name where the first param is the collection name
db.mycoll.save(obj)
db.mycoll.stats()
db.mycoll.storageSize() - includes free space allocated to this collection
db.mycoll.totalIndexSize() - size in bytes of all the indexes
db.mycoll.totalSize() - storage allocated for all data and indexes
db.mycoll.update(query, object[, upsert_bool, multi_bool]) - instead of two flags, you can pass an object with fields: upsert, multi
db.mycoll.validate( <full> ) - SLOW
db.mycoll.getShardVersion() - only for use with sharding
db.mycoll.getShardDistribution() - prints statistics about data distribution in the cluster
db.mycoll.getSplitKeysForChunks( <maxChunkSize> ) - calculates split points over all chunks and returns splitter function
db.mycoll.getWriteConcern() - returns the write concern used for any operations on this collection, inherited from server/db if set
db.mycoll.setWriteConcern( <write concern doc> ) - sets the write concern for writes to the collection
db.mycoll.unsetWriteConcern( <write concern doc> ) - unsets the write concern for writes to the collection有关数据库和集合管理的相关命令，是最基础和最常用的，如集合查询、索引操作等。
三、常用命令实例
1.超级用户相关
use admin
#增加或修改用户密码
db.addUser(ixigua,'pwd')
#查看用户列表
db.system.users.find()
#用户认证
db.auth(ixigua,'pwd')
#删除用户
db.removeUser('mongodb')
#查看所有用户
show users
#查看所有数据库
show dbs
#查看所有的collection
show collections
#查看各collection的状态
db.printCollectionStats()
#查看主从复制状态
db.printReplicationInfo()
#修复数据库
db.repairDatabase()
#设置记录profiling，0=off 1=slow 2=all
db.setProfilingLevel(1)
#查看profiling
show profile
#拷贝数据库
db.copyDatabase('mail_addr','mail_addr_tmp')
#删除collection
db.mail_addr.drop()
#删除当前的数据库
db.dropDatabase()
2.数据增删改
#存储嵌套的对象
db.foo.save({'name':'ysz','address':{'city':'beijing','post':100096},'phone':[138,139]})
#存储数组对象
db.user_addr.save({'Uid':'[email protected]','Al':['[email protected]','[email protected]']})
#根据query条件修改，如果不存在则插入，允许修改多条记录
db.foo.update({'yy':5},{'$set':{'xx':2}},upsert=true,multi=true)
#删除yy=5的记录
db.foo.remove({'yy':5})
#删除所有的记录
db.foo.remove()
3.索引
#增加索引：1(ascending),-1(descending)
db.things.ensureIndex({firstname: 1, lastname: 1}, {unique: true});
#索引子对象
db.user_addr.ensureIndex({'Al.Em': 1})
#查看索引信息
db.deliver_status.getIndexes()
db.deliver_status.getIndexKeys()
#根据索引名删除索引
db.user_addr.dropIndex('Al.Em_1')
4.查询
#查找所有
db.foo.find()
#查找一条记录
db.foo.findOne()
#根据条件检索10条记录
db.foo.find({'msg':'Hello 1'}).limit(10)
#sort排序
db.deliver_status.find({'From':'[email protected]'}).sort({'Dt',-1})
db.deliver_status.find().sort({'Ct':-1}).limit(1)
#count操作
db.user_addr.count()
#distinct操作
db.foo.distinct('msg')
#>操作
db.foo.find({"timestamp": {"$gte" : 2}})
#子对象的查找
db.foo.find({'address.city':'beijing'})
5.管理
#查看collection数据的大小 db.deliver_status.dataSize() #查看colleciont状态 db.deliver_status.stats() #查询所有索引的大小 db.deliver_status.totalIndexSize() #查看当前所使用的数据库 db6.条件操作符
gt:>
lt:<
gte:>=
lte:<=
ne:!=、<>
in:in
nin:notin
all: all
$not: 反匹配(1.3.3及以上版本)
参考文档：
http://blog.csdn.net/shirdrn/article/details/7105539
http://www.jb51.net/article/48217.htm
http://www.cnblogs.com/xusir/archive/2012/12/24/2830957.html