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MongoDB安装及增删改查操作

时间:2012-12-26 14:52来源:CU 编辑:tkchks 点击:
使用mongodb进行增删改查等基本操作。本例使用 mongodb-win32-i386-2.0.8 , 在windows xp下进行测试。 MongoDB客户端和服务端都运行在本地(同一台机器)。 1.安装MongoDB 1.1.下载 mongodb ,并解压,本
使用mongodb进行增删改查等基本操作。本例使用 mongodb-win32-i386-2.0.8 , 在windows xp下进行测试。 MongoDB客户端和服务端都运行在本地(同一台机器)。
1.安装MongoDB
1.1.下载mongodb,并解压,本例安装在D:\J2ee\mongodb-win32-i386-2.0.8

1.2.使用mongod.exe启动mongodb
$MongoDB-folder/bin/mongod
    D:\J2ee\mongodb-win32-i386-2.0.8\bin>mongod
    mongod --help for help and startup options
    Mon Dec 24 14:56:35
    Mon Dec 24 14:56:35 warning: 32-bit servers don't have journaling enabled by def
    ault. Please use --journal if you want durability.
    Mon Dec 24 14:56:35
    Mon Dec 24 14:56:35 [initandlisten] MongoDB starting : pid=1452 port=27017 dbpat
    h=/data/db 32-bit host=chenzhengwei
    Mon Dec 24 14:56:35 [initandlisten]
    Mon Dec 24 14:56:35 [initandlisten] ** NOTE: when using MongoDB 32 bit, you are
    limited to about 2 gigabytes of data
    Mon Dec 24 14:56:35 [initandlisten] ** see http://blog.mongodb.org/post/13
    7788967/32-bit-limitations
    Mon Dec 24 14:56:35 [initandlisten] ** with --journal, the limit is lower
    Mon Dec 24 14:56:35 [initandlisten]
    Mon Dec 24 14:56:35 [initandlisten] db version v2.0.8, pdfile version 4.5
    Mon Dec 24 14:56:35 [initandlisten] git version: a340a57af7cdda865da420704e1d1b2
    fac0cedc2
    Mon Dec 24 14:56:35 [initandlisten] build info: windows sys.getwindowsversion(ma
    jor=6, minor=0, build=6002, platform=2, service_pack='Service Pack 2') BOOST_LIB
    _VERSION=1_42
    Mon Dec 24 14:56:35 [initandlisten] options: {}
    Mon Dec 24 14:56:35 [initandlisten] exception in initAndListen: 10296 dbpath (/d
    ata/db) does not exist, terminating
    Mon Dec 24 14:56:35 dbexit:
    Mon Dec 24 14:56:35 [initandlisten] shutdown: going to close listening sockets..
    .
    Mon Dec 24 14:56:35 [initandlisten] shutdown: going to flush diaglog...
    Mon Dec 24 14:56:35 [initandlisten] shutdown: going to close sockets...
    Mon Dec 24 14:56:35 [initandlisten] shutdown: waiting for fs preallocator...
    Mon Dec 24 14:56:35 [initandlisten] shutdown: closing all files...
    Mon Dec 24 14:56:35 [initandlisten] closeAllFiles() finished
    Mon Dec 24 14:56:35 dbexit: really exiting now

以上并没有启动mongod,抛出了以下异常信息:
    Mon Dec 24 14:56:35 [initandlisten] exception in initAndListen: 10296 dbpath (/d
    ata/db) does not exist, terminating

即dbpath(/data/db)不存在

正确方法,创建目录D:\J2ee\mongodb-win32-i386-2.0.8\data,用于mongodb存放数据。

执行以下命令:
    D:\J2ee\mongodb-win32-i386-2.0.8\bin>mongod -dbpath D:\J2ee\mongodb-win32-i386-2
    .0.8\data
    Mon Dec 24 15:17:03
    Mon Dec 24 15:17:03 warning: 32-bit servers don't have journaling enabled by def
    ault. Please use --journal if you want durability.
    Mon Dec 24 15:17:03
    Mon Dec 24 15:17:03 [initandlisten] MongoDB starting : pid=5884 port=27017 dbpat
    h=D:\J2ee\mongodb-win32-i386-2.0.8\data 32-bit host=chenzhengwei
    Mon Dec 24 15:17:03 [initandlisten]
    Mon Dec 24 15:17:03 [initandlisten] ** NOTE: when using MongoDB 32 bit, you are
    limited to about 2 gigabytes of data
    Mon Dec 24 15:17:03 [initandlisten] ** see http://blog.mongodb.org/post/13
    7788967/32-bit-limitations
    Mon Dec 24 15:17:03 [initandlisten] ** with --journal, the limit is lower
    Mon Dec 24 15:17:03 [initandlisten]
    Mon Dec 24 15:17:03 [initandlisten] db version v2.0.8, pdfile version 4.5
    Mon Dec 24 15:17:03 [initandlisten] git version: a340a57af7cdda865da420704e1d1b2
    fac0cedc2
    Mon Dec 24 15:17:03 [initandlisten] build info: windows sys.getwindowsversion(ma
    jor=6, minor=0, build=6002, platform=2, service_pack='Service Pack 2') BOOST_LIB
    _VERSION=1_42
    Mon Dec 24 15:17:03 [initandlisten] options: { dbpath: "D:\J2ee\mongodb-win32-i3
    86-2.0.8\data" }
    Mon Dec 24 15:17:03 [initandlisten] waiting for connections on port 27017
    Mon Dec 24 15:17:03 [websvr] admin web console waiting for connections on port 2
    8017

2. 连接MongoDB
再打开一个命令行,执行以下mongo命令:
    D:\J2ee\mongodb-win32-i386-2.0.8\bin>mongo
    MongoDB shell version: 2.0.8
    connecting to: test

3. 创建数据库和表
mongodb中使用以下命令,切换到某个数据库(即使它还不存在)
use database-name

mongodb中当你往一个表里面插入一条记录时,相应的表和数据库就被自动创建好了。具体看下面的例子:
    D:\J2ee\mongodb-win32-i386-2.0.8\bin>mongo
    MongoDB shell version: 2.0.8
    connecting to: test
    > use mydb
    switched to db mydb
    > db.users.insert({username:"henry",password:"123456"})
    > db.users.find()
    { "_id" : ObjectId("50d803393cc996b4e8ce22de"), "username" : "henry", "password"
    : "123456" }
    >

以下是三个常用的命令
    show dbs – List all databases.
    use db_name – Switches to db_name.
    show collections – List all tables in the current selected database.
    > show dbs
    local (empty)
    mydb 0.03125GB
    > use mydb
    switched to db mydb
    > show collections
    system.indexes
    users
    >

In MongoDB, collection means table in SQL.

4. 插入一条记录
插入记录的语法的两种方式:
db.tablename.insert({data}) or db.tablename.save({data})
    > db.users.save({username:"google",password:"google123"})
    > db.users.find()
    { "_id" : ObjectId("50d803393cc996b4e8ce22de"), "username" : "henry", "password": "123456" }
    { "_id" : ObjectId("50d8046a3cc996b4e8ce22df"), "username" : "google", "password" : "google123" }

5. 更新记录
更新一条记录语法:
db.tablename.update({criteria},{$set: {new value}}).

下面的例子中更新用户henry的密码:
    > db.users.update({username:"henry"},{$set:{password:"henry123456"}})
    > db.users.find()
    { "_id" : ObjectId("50d8046a3cc996b4e8ce22df"), "username" : "google", "password" : "google123" }
    { "_id" : ObjectId("50d803393cc996b4e8ce22de"), "password" : "henry123456", "username" : "henry" }
    >

6. 查询记录
查找记录的语法:
db.tablename.find({criteria}).

6.1 列出users表中的所有记录
    > db.users.find()
    { "_id" : ObjectId("50d8046a3cc996b4e8ce22df"), "username" : "google", "password" : "google123" }
    { "_id" : ObjectId("50d803393cc996b4e8ce22de"), "password" : "henry123456", "username" : "henry" }
    >

6.2 查询username 为henry的记录
    > db.users.find({username:"henry"})
    { "_id" : ObjectId("50d803393cc996b4e8ce22de"), "password" : "henry123456", "username" : "henry" }

7. 删除记录
删除记录的语法:
db.tablename.remove({criteria}).

下面的例子
    > db.users.remove({username:"google"})
    > db.users.find()
    { "_id" : ObjectId("50d803393cc996b4e8ce22de"), "password" : "henry123456", "username" : "henry" }
    >

To delete all records from a table, uses db.tablename.remove().
To drop the table, uses db.tablename.drop().

8. 索引
Index(索引)可以提高查询的效率

8.1 List all indexes of table “users”, by default the column “_id” is always the primary key and created automatically.
    > db.users.getIndexes()
    [
    {
    "v" : 1,
    "key" : {
    "_id" : 1
    },
    "ns" : "mydb.users",
    "name" : "_id_"
    }
    ]
    >

8.2 To create an index, uses db.tablename.ensureIndex(column). In below example, an index is created on column “username”.
    > db.users.ensureIndex({username:1})
    > db.users.getIndexes()
    [
    {
    "v" : 1,
    "key" : {
    "_id" : 1
    },
    "ns" : "mydb.users",
    "name" : "_id_"
    },
    {
    "v" : 1,
    "key" : {
    "username" : 1
    },
    "ns" : "mydb.users",
    "name" : "username_1"
    }
    ]
    >

8.3 To drop an index, uses db.tablename.dropIndex(column). In below example, the index on column “username” is deleted or dropped.
    > db.users.dropIndex({username:1})
    { "nIndexesWas" : 2, "ok" : 1 }
    > db.users.getIndexes()
    [
    {
    "v" : 1,
    "key" : {
    "_id" : 1
    },
    "ns" : "mydb.users",
    "name" : "_id_"
    }
    ]
    >

8.4 To create an unique index, uses db.tablename.ensureIndex({column},{unique:true}). In below example, an unique index is created on column “username”.
    > db.users.ensureIndex({username:1},{unique:true});
    > db.users.getIndexes()
    [
    {
    "v" : 1,
    "key" : {
    "_id" : 1
    },
    "ns" : "mydb.users",
    "name" : "_id_"
    },
    {
    "v" : 1,
    "key" : {
    "username" : 1
    },
    "unique" : true,
    "ns" : "mydb.users",
    "name" : "username_1"
    }
    ]
    >

9. 帮助
At last, uses help() to guide you how to do things in MongoDB.

9.1 help – All available commands.
    > help
    db.help() help on db methods
    db.mycoll.help() help on collection methods
    rs.help() help on replica set methods
    help admin administrative help
    help connect connecting to a db help
    help keys key shortcuts
    //...

9.2 db.help() – Shows help on db.
    > db.help()
    DB methods:
    db.addUser(username, password[, readOnly=false])
    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.currentOp() displays the current operation in the db
    db.dropDatabase()
    db.eval(func, args) run code server-side
    db.getCollection(cname) same as db['cname'] or db.cname
    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 this connection to read from the nonmas
    ter member of a replica pair
    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.isMaster() check replica primary status
    db.killOp(opid) kills the current operation in the db
    db.listCommands() lists all the db commands
    db.logout()
    db.printCollectionStats()
    db.printReplicationInfo()
    db.printSlaveReplicationInfo()
    db.printShardingStatus()
    db.removeUser(username)
    db.repairDatabase()
    db.resetError()
    db.runCommand(cmdObj) run a database command. if cmdObj is a string, tu
    rns it into { cmdObj : 1 }
    db.serverStatus()
    db.setProfilingLevel(level,) 0=off 1=slow 2=all
    db.shutdownServer()
    db.stats()
    db.version() current version of the server
    db.getMongo().setSlaveOk() allow queries on a replication slave server
    db.fsyncLock() flush data to disk and lock server for backups
    db.fsyncUnock() unlocks server following a db.fsyncLock()
    >

9.3 db.collection.help() – Shows help on collection (table).
    > db.users.help()
    DBCollection help
    db.users.find().help() - show DBCursor help
    db.users.count()
    db.users.dataSize()
    db.users.distinct( key ) - eg. db.users.distinct( 'x' )
    db.users.drop() drop the collection
    db.users.dropIndex(name)
    //...

9..4 db.collection.function.help() – Shows help on function.
    > db.users.find().help()
    find() modifiers
    .sort( {...} )
    .limit( n )
    .skip( n )
    .count() - total # of objects matching query, ignores skip,limit
    .size() - total # of objects cursor would return, honors skip,limit
    .explain([verbose])
    //...

Done. Hope this summary of MongoDB commands could help others.
References

Official MongoDB tutorials
MongoDB Indexes

http://docs.mongodb.org/manual/tutorial/install-mongodb-on-windows/

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