查看命令的方式:
1.在shell中运行db.listCommands()
2.在浏览器中访问管理员接口:http://ipaddress:28017/_commands
下面介绍在Mongodb中最经常使用的命令,具体如下:
命令:buildInfo
格式:{"buildInfo":1}
介绍:管理专用命令,返回Mongodb服务器的版本号和主机的操作系统。
示例:
> db.runCommand({"buildInfo":1}) { "version" : "2.0.6", "gitVersion" : "e1c0cbc25863f6356aa4e31375add7bb49fb05bc", "sysInfo" : "Linux domU-12-31-39-01-70-B4 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_41", "versionArray" : [ 2, 0, 6, 0 ], "bits" : 32, "debug" : false, "maxBsonObjectSize" : 16777216, "ok" : 1 }
命令:collStats
格式:{"collStats":collection}
介绍:返回指定集合的统计信息,包括数据大小、已分配的存储空间和索引的大小。
示例:
> db.runCommand({"collStats":"users"}) { "ns" : "test.users", "count" : 3, "size" : 508, "avgObjSize" : 169.33333333333334, "storageSize" : 4096, "numExtents" : 1, "nindexes" : 2, "lastExtentSize" : 4096, "paddingFactor" : 1.51, "flags" : 0, "totalIndexSize" : 16352, "indexSizes" : { "_id_" : 8176, "name_1" : 8176 }, "ok" : 1 }
命令:distinct
格式:{"distinct":collection,"key":key,"query":query}
介绍:列出指定集合中满足查询条件的文档的指定键的所有不同值
示例:
> db.runCommand({"distinct":"foo","key":"name","query":{"age":{"$gt":20}}}) { "values" : [ "gongyong", "chenzhou", "yixin" ], "stats" : { "n" : 4, "nscanned" : 6, "nscannedObjects" : 6, "timems" : 50, "cursor" : "BasicCursor" }, "ok" : 1 }
命令:drop
格式:{"drop":collection}
介绍:删除集合的所有数据
示例:
> db.bbb.save({"x":1,"y":2}) #先往bbb中存一条记录 > db.bbb.find() #查询bbb中的数据 { "_id" : ObjectId("5027d919831a10b0f6e61385"), "x" : 1, "y" : 2 } #使用drop命令删除bbb集合中的数据 > db.runCommand({"drop":"bbb"}) { "nIndexesWas" : 1, "msg" : "indexes dropped for collection", "ns" : "test.bbb", "ok" : 1 } > db.bbb.find() #再次查询,结果为空
命令:dropDatabase
格式:{"dropDatabase":1}
介绍:删除当前数据库中的所有数据
示例:略
命令:dropIndexes
格式:{"dropIndexes":collection,"index":name}
介绍:删除集合里面名称为name的索引,如果名称为"*",则删除全部索引。
示例:
> db.system.indexes.find() { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.foo", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.users", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.games", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.blog.post", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.lists", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.math", "name" : "_id_" } { "v" : 1, "key" : { "name" : 1 }, "ns" : "test.users", "name" : "name_1" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.map", "name" : "_id_" } { "v" : 1, "key" : { "gps" : "2d" }, "ns" : "test.map", "name" : "gps_", "min" : -180, "max" : 181 } > db.runCommand({"dropIndexes":"users","index":"name_1"}) { "nIndexesWas" : 2, "ok" : 1 } > db.system.indexes.find() { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.foo", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.users", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.games", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.blog.post", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.lists", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.math", "name" : "_id_" } { "v" : 1, "key" : { "_id" : 1 }, "ns" : "test.map", "name" : "_id_" } { "v" : 1, "key" : { "gps" : "2d" }, "ns" : "test.map", "name" : "gps_", "min" : -180, "max" : 181 }
命令:findAndModify
格式:
介绍:查找并修改
示例:
> db.foo.find({"name":"yixin"}) { "_id" : ObjectId("5027d84b831a10b0f6e61384"), "name" : "yixin", "age" : 23 } > db.runCommand({"findAndModify":"foo", ... "query":{"name":"yixin"}, ... "update":{"$inc":{"age":1}}}) #把name为yixin的记录中age值加1 { "lastErrorObject" : { "updatedExisting" : true, "n" : 1, "connectionId" : 2, "err" : null, "ok" : 1 }, "value" : { "_id" : ObjectId("5027d84b831a10b0f6e61384"), "name" : "yixin", "age" : 23 }, "ok" : 1 } > db.foo.find({"name":"yixin"}) { "_id" : ObjectId("5027d84b831a10b0f6e61384"), "name" : "yixin", "age" : 24 }
命令:getLastError
格式:{"getLastError":1[ , "w":w[ , "wtimeout":timeout}
介绍:查看对本集合执行的最后一次操作的错误信息或者其它状态信息。在w台服务器复制集合的最后操作之前,这个命令会阻塞。
示例:
> db.runCommand({"getLastError":1}) { "n" : 0, "connectionId" : 2, "err" : null, "ok" : 1 }
命令:isMaster
格式:{"isMaster":1}
介绍:检查本服务器是主服务器还是从服务器
示例:
> db.runCommand({"isMaster":1}) { "ismaster" : true, "maxBsonObjectSize" : 16777216, "ok" : 1 }
命令:listCommands
格式:{"listCommands":1}
介绍:返回所有可以在服务器上运行的命令及相关信息。
示例: 返回结果太多,示例就省略了
命令:listDatabases
格式:{"listDatabases":1}
介绍:管理专用命令,列出服务器上所有的数据库
示例:
> db.runCommand({"listDatabases":1}) { "errmsg" : "access denied; use admin db", "ok" : 0 } #报错,提示访问被拒绝,要求必须使用admin数据库 > use admin #切换到admin数据库 switched to db admin > db.runCommand({"listDatabases":1}) { "databases" : [ { "name" : "test", "sizeOnDisk" : 67108864, "empty" : false }, { "name" : "results", "sizeOnDisk" : 67108864, "empty" : false }, { "name" : "admin", "sizeOnDisk" : 1, "empty" : true }, { "name" : "local", "sizeOnDisk" : 1, "empty" : true } ], "totalSize" : 134217728, "ok" : 1 }
命令:ping
格式:{"ping":1}
介绍:检查服务器链接是否正常。即便服务器上锁了,这条命令也会立刻返回
示例:
> db.runCommand({"ping":1}) { "ok" : 1 }
命令:renameCollection
格式:{"renameCollection":a,"to":b}
介绍:将集合a重命名为b,其中a和b都必须是完整的集合命名空间(例如"test.foo"代表test数据库中的foo集合)
示例:
> db.runCommand({"renameCollection":"foo","to":"foo_bak"}) { "errmsg" : "access denied; use admin db", "ok" : 0 } > use admin switched to db admin > db.runCommand({"renameCollection":"foo","to":"foo_bak"}) { "errmsg" : "exception: source namespace does not exist", "code" : 10026, "ok" : 0 } > db.runCommand({"renameCollection":"test.foo","to":"test.foo_bak"}) { "ok" : 1 } > db.foo_bak.find() > use test switched to db test > db.foo_bak.find() { "_id" : ObjectId("502149203e2ff9961cc7b555"), "name" : "chenzhou" } { "_id" : ObjectId("502149353e2ff9961cc7b556"), "age" : 23 } { "_id" : ObjectId("5021495c3e2ff9961cc7b557"), "name" : "gongyong", "age" : 26 } { "_id" : ObjectId("50214ad63e2ff9961cc7b558"), "name" : "chenzhou", "age" : 22, "friends" : 500, "enemies" : 2 } { "_id" : 123, "x" : 1 } { "_id" : ObjectId("5027d84b831a10b0f6e61384"), "name" : "yixin", "age" : 24 }
命令:repairDatabase
格式:{"repairDatabase":1}
介绍:修复并压缩当前数据库,这个操作可能非常耗时。
示例:略
命令:serverStatus
格式:{"serverStatus":1}
介绍:返回这台服务器的管理统计信息。
示例:
> db.runCommand({"serverStatus":1}) { "host" : "localhost.localdomain", "version" : "2.0.6", "process" : "mongod", "uptime" : 3661, "uptimeEstimate" : 2987, "localTime" : ISODate("2012-08-12T17:07:05.076Z"), "globalLock" : { "totalTime" : 3659420009, "lockTime" : 609397, "ratio" : 0.00016652830188971076, "currentQueue" : { "total" : 0, "readers" : 0, "writers" : 0 }, "activeClients" : { "total" : 0, "readers" : 0, "writers" : 0 } }, "mem" : { "bits" : 32, "resident" : 45, "virtual" : 158, "supported" : true, "mapped" : 64 }, "connections" : { "current" : 1, "available" : 818 }, "extra_info" : { "note" : "fields vary by platform", "heap_usage_bytes" : 491848, "page_faults" : 0 }, "indexCounters" : { "btree" : { "accesses" : 1, "hits" : 1, "misses" : 0, "resets" : 0, "missRatio" : 0 } }, "backgroundFlushing" : { "flushes" : 60, "total_ms" : 119, "average_ms" : 1.9833333333333334, "last_ms" : 0, "last_finished" : ISODate("2012-08-12T17:06:05.816Z") }, "cursors" : { "totalOpen" : 0, "clientCursors_size" : 0, "timedOut" : 0 }, "network" : { "bytesIn" : 7312, "bytesOut" : 63515, "numRequests" : 102 }, "opcounters" : { "insert" : 2, "query" : 29, "update" : 1, "delete" : 0, "getmore" : 0, "command" : 75 }, "asserts" : { "regular" : 0, "warning" : 0, "msg" : 0, "user" : 1, "rollovers" : 0 }, "writeBacksQueued" : false, "ok" : 1 }