查询所有数据库列表

CODE:

show dbs

如果想查看当前连接在哪个数据库下面,可以直接输入db

CODE:

db
Admin
想切换到test数据库下面

CODE:

use test
switched to db test
db
Test
想查看test下有哪些表或者叫collection,可以输入

CODE:

show collections
system.indexes
user
想知道mongodb支持哪些命令,可以直接输入help

CODE:

help
HELP
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
use set curent database to
db.help() help on DB methods
db.foo.help() help on collection methods
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
如果想知道当前数据库支持哪些方法:

CODE:

db.help();
DB methods:
db.addUser(username, password) 添加数据库授权用户
db.auth(username, password) 访问认证
db.cloneDatabase(fromhost) 克隆数据库
db.commandHelp(name) returns the help for the command
db.copyDatabase(fromdb, todb, fromhost) 复制数据库
db.createCollection(name, { size : ..., capped : ..., max : ... } ) 创建表
db.currentOp() displays the current operation in the db
db.dropDatabase() 删除当前数据库
db.eval_r(func, args) run code server-side
db.getCollection(cname) same as db['cname'] or db.cname
db.getCollectionNames() 获取当前数据库的表名
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 this connection to read from the nonmaster member of a replica pair
db.getName()
db.getPrevError()
db.getProfilingLevel()
db.getReplicationInfo()
db.getSisterDB(name) get the db at the same server as this onew
db.killOp() kills the current operation in the db
db.printCollectionStats() 打印各表的状态信息
db.printReplicationInfo() 打印主数据库的复制状态信息
db.printSlaveReplicationInfo() 打印从数据库的复制状态信息
db.printShardingStatus() 打印分片状态信息
db.removeUser(username) 删除数据库用户
db.repairDatabase() 修复数据库
db.resetError()
db.runCommand(cmdObj) run a database command. if cmdObj is a string, turns it into { cmdObj : 1 }
db.setProfilingLevel(level) 0=off 1=slow 2=all
db.shutdownServer()
db.version() current version of the server
如果想知道当前数据库下的表或者表collection支持哪些方法,可以使用一下命令如:

CODE:

db.user.help(); user为表名
DBCollection help
db.foo.count() 统计表的行数
db.foo.dataSize() 统计表数据的大小
db.foo.distinct( key ) - eg. db.foo.distinct( 'x' ) 按照给定的条件除重
db.foo.drop() drop the collection 删除表
db.foo.dropIndex(name) 删除指定索引
db.foo.dropIndexes() 删除所有索引
db.foo.ensureIndex(keypattern,options) - options should be an object with these possible fields: name, unique, dropDups 增加索引
db.foo.find( [query] , [fields]) - first parameter is an optional query filter. second parameter is optional set of fields to return. 根据条件查找数据


通过条件查询: db.foo.find( { x : 77 } , { name : 1 , x : 1 } )

   db.foo.find(...).count()
   db.foo.find(...).limit(n) 根据条件查找数据并返回指定记录数
   db.foo.find(...).skip(n)
   db.foo.find(...).sort(...) 查找排序
   db.foo.findOne([query]) 根据条件查询只查询一条数据
   db.foo.getDB() get DB object associated with collection  返回表所属的库
   db.foo.getIndexes() 显示表的所有索引
   db.foo.group( { key : ..., initial: ..., reduce : ...[, cond: ...] } ) 根据条件分组
   db.foo.mapReduce( mapFunction , reduceFunction , <optional params> )
   db.foo.remove(query) 根据条件删除数据
   db.foo.renameCollection( newName ) renames the collection  重命名表
   db.foo.save(obj) 保存数据
   db.foo.stats()  查看表的状态
   db.foo.storageSize() - includes free space allocated to this collection 查询分配到表空间大小
   db.foo.totalIndexSize() - size in bytes of all the indexes 查询所有索引的大小
   db.foo.totalSize() - storage allocated for all data and indexes 查询表的总大小
   db.foo.update(query, object[, upsert_bool]) 根据条件更新数据
   db.foo.validate() - SLOW 验证表的详细信息
   db.foo.getShardVersion() - only for use with sharding

Mongodb的备份工具mongodump

如果想备份数据库test 如:

CODE:

[falcon@www.fwphp.cn ~/mongodb/bin]$ ./mongodump --help
options:
--help produce help message
-h [ --host ] arg mongo host to connect to
-d [ --db ] arg database to use
-c [ --collection ] arg collection to use (some commands)
-u [ --username ] arg username
-p [ --password ] arg password
--dbpath arg directly access mongod data files in this path,
instead of connecting to a mongod instance
-v [ --verbose ] be more verbose (include multiple times for more
verbosity e.g. -vvvvv)
-o [ --out ] arg (=dump) output directory
[falcon@www.fwphp.cn ~/mongodb/bin]$ [color=Blue]./mongodump -d test -o test/[/color]
connected to: 127.0.0.1
DATABASE: test to test/test
test.user to test/test/user.bson
100000 objects
test.system.indexes to test/test/system.indexes.bson
1 objects
[falcon@www.fwphp.cn ~/mongodb/bin]$ ls
2 mongo mongodump mongofiles mongorestore mongosniff
dump mongod mongoexport mongoimport mongos test
MongoDB的数据恢复工具mongorestore

查看test库中的表

CODE:

show collections
system.indexes
User
删除user表

CODE:

db.user.drop();
True

show collections
System.indexes
现在利用mongorestore表恢复刚才利用mongodump备份的数据

CODE:

[falcon@www.fwphp.cn ~/mongodb/bin]$ ./mongorestore --help
usage: ./mongorestore [options] [directory or filename to restore from]
options:
--help produce help message
-h [ --host ] arg mongo host to connect to
-d [ --db ] arg database to use
-c [ --collection ] arg collection to use (some commands)
-u [ --username ] arg username
-p [ --password ] arg password
--dbpath arg directly access mongod data files in this path,
instead of connecting to a mongod instance
-v [ --verbose ] be more verbose (include multiple times for more
verbosity e.g. -vvvvv)

[falcon@www.fwphp.cn ~/mongodb/bin]$ ./mongorestore -d test -c user test/test/user.bson
connected to: 127.0.0.1
test/test/user.bson
going into namespace [test.user]

    100000 objects

User表中的10w条记录已经恢复

CODE:

show collections
system.indexes
user
db.user.find();
{ "_id" : ObjectId("4b9c8db08ead0e3347000000"), "uid" : 1, "username" : "Falcon.C-1" }
{ "_id" : ObjectId("4b9c8db08ead0e3347010000"), "uid" : 2, "username" : "Falcon.C-2" }
{ "_id" : ObjectId("4b9c8db08ead0e3347020000"), "uid" : 3, "username" : "Falcon.C-3" }
{ "_id" : ObjectId("4b9c8db08ead0e3347030000"), "uid" : 4, "username" : "Falcon.C-4" }
{ "_id" : ObjectId("4b9c8db08ead0e3347040000"), "uid" : 5, "username" : "Falcon.C-5" }
.................
has more

  1. 超级用户相关:

    #增加或修改用户密码

    db.addUser('admin','pwd')

    #查看用户列表

    db.system.users.find()

    #用户认证

    db.auth('admin','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. 客户端连接

    /usr/local/mongodb/bin/mongo user_addr -u user -p 'pwd'
    
  3. 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':'yushunzhi@sohu.com','Al':['test-1@sohu.com','test-2@sohu.com']})
    
    #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()

  4. 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')
    
  5. 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':'yushunzhi@sohu.com'}).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'})

  6. 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()
    

mysql:
SELECT * FROM user
Mongo:
db.user.find()
——————————————
mysql:
SELECT * FROM user WHERE name = 'foobar'
Mongo:
db.user.find({ 'name' : 'foobar' })
——————————————
MySql:
INSERT INTO user ('name','age') VALUES ('foobar',25)
Mongo:
db.user.insert({ 'name' : 'foobar' , 'age' : 25})
——————————————
如果想增加email这一列
MySql:
ALTER TABLE user ...
Mongo:
db.user.insert({ 'name' : 'foobar' , 'age' : 25 , 'email' : 'foo@bar.com' })
——————————————
MySql:
DELETE * FROM user
Mongo:
db.user.remove({})
——————————————
MySql:
DELETE FROM user WHERE age < 30
Mongo:
db.user.remove({ 'age' : {$lt : 30}})
$gt:> ; $gte:>= ; $lt:< ; $lte:<= ; $ne:!=
——————————————
MySql:
UPDATE user SET age = 36 WHERE name = 'foobar'
Mongo:
db.user.update({ 'name' : 'foobar'} , {$set : { 'age' : 36}})
——————————————
MySQL:
UPDATE user SET age = 'age' + 3 WHERE name = 'foobar'
Mongo:
db.user.update({ 'name' : 'foobar'} , {$inc : {'age' : 3}})
——————————————
MySQl:
SELECT COUNT(*) FROM user WHERE name = 'foobar'
Mongo:
db.user.find({ 'name' : 'foobar'}).count()
——————————————
MySql:
SELECT * FROM user limit 10,20
Mongo:
db.user.find().skip(10).limit(20)
——————————————
MySQl:
SELECT * FROM user WHERE age IN (25,35,45)
Mongo:
db.user.find({ 'age' : {$in : [25,35,45]}})
——————————————
MySql:
SELECT * FROM user ORDER BY age DESC
Mongo:
db.user.find().sort({ 'age' : -1})
——————————————
MySQL:
SELECT DISTINCT(name) FROM user WHERE age > 20
Mongo:
db.user.distinct( 'name',{'age' : {$lt : 20}})
——————————————
MySQL:
SELECT name, sum(marks) FROM user GROUP BY name
Mongo:
db.user.group({
key:{'name':true},
cond:{'name':'foo'},
reduce:function(obj,prev){prev.msum += obj.marks;},
initial:{msum : 0}
})
——————————————
MySQL:
SELECT name FROM user WHERE age < 20
Mongo:
db.user.find('this.age < 20' , {name : 1})