MongoDB数据表基本操作

查看全部数据表

>useChatRoom
switchedtodbChatRoom
>showcollections
Account
Chat
system.indexes
system.users

创建数据表

>db.createCollection("Account")
{"ok":1}

> db.createCollection("Test",{capped:true, size:10000}) { "ok" : 1 }

{"ok":1}

-- 说明

capped:true，表示该集合的结构不能被修改；

size:在建表之初就指定一定的空间大小，接下来的插入操作会不断地按顺序APPEND数据在这个预分配好空间的文件中，如果已经超出空间大小，则回到文件头覆盖原来的数据继续插入。这种结构保证了插入和查询的高效性，它不允许删除单个记录，更新的也有限制：不能超过原有记录的大小。这种表效率很高，它适用于一些暂时保存数据的场合，比如网站中登录用户的session信息，又比如一些程序的监控日志，都是属于过了一定的时间就可以被覆盖的数据。

修改数据表名

>db.Account.renameCollection("Account1")
{"ok":1}

数据表帮助主题help

>db.Account.help()
DBCollectionhelp
db.Account.find().help()-showDBCursorhelp
db.Account.count()
db.Account.dataSize()
db.Account.distinct(key)-eg.db.Account.distinct('x')
db.Account.drop()dropthecollection
db.Account.dropIndex(name)
db.Account.dropIndexes()
db.Account.ensureIndex(keypattern[,options])-optionsisanobjectwiththesepossiblefields:name,unique,dropDups
db.Account.reIndex()
db.Account.find([query],[fields])-queryisanoptionalqueryfilter.fieldsisoptionalsetoffieldstoreturn.
e.g.db.Account.find({x:77},{name:1,x:1})
db.Account.find(...).count()
db.Account.find(...).limit(n)
db.Account.find(...).skip(n)
db.Account.find(...).sort(...)
db.Account.findOne([query])
db.Account.findAndModify({update:...,remove:bool[,query:{},sort:{},'new':false]})
db.Account.getDB()getDBobjectassociatedwithcollection
db.Account.getIndexes()
db.Account.group({key:...,initial:...,reduce:...[,cond:...]})
db.Account.mapReduce(mapFunction,reduceFunction,<optionalparams>)
db.Account.remove(query)
db.Account.renameCollection(newName,<dropTarget>)renamesthecollection.
db.Account.runCommand(name,<options>)runsadbcommandwiththegivennamewherethefirstparamisthecollectionname
db.Account.save(obj)
db.Account.stats()
db.Account.storageSize()-includesfreespaceallocatedtothiscollection
db.Account.totalIndexSize()-sizeinbytesofalltheindexes
db.Account.totalSize()-storageallocatedforalldataandindexes
db.Account.update(query,object[,upsert_bool,multi_bool])
db.Account.validate()-SLOW
db.Account.getShardVersion()-onlyforusewithsharding

查看全部表记录

>db.Account.find()
{"_id":ObjectId("4df08553188e444d001a763a"),"AccountID":1,"UserName":"libing","Password":"1","Age":26,"Email":"[e-mail]","RegisterDate":"2011-06-0916:31:25"}
{"_id":ObjectId("4df08586188e444d001a763b"),"AccountID":2,"UserName":"lb","Password":"1","Age":25,"Email":"[e-mail]","RegisterDate":"2011-06-0916:36:95"}

--SELECT * FROM Account

说明：

默认每页显示20条记录，当显示不下的情况下，可以用it迭代命令查询下一页数据。
可以通过DBQuery.shellBatchSize设置每页显示数据的大小。如：DBQuery.shellBatchSize = 5，这样每页就显示5条记录了。

>db.Test.find()
{"_id":ObjectId("4df6d55407444568af61cfea"),"TestID":1}
{"_id":ObjectId("4df6d55907444568af61cfeb"),"TestID":2}
{"_id":ObjectId("4df6d55b07444568af61cfec"),"TestID":3}
{"_id":ObjectId("4df6d55e07444568af61cfed"),"TestID":4}
{"_id":ObjectId("4df6d56207444568af61cfee"),"TestID":5}
{"_id":ObjectId("4df6d56507444568af61cfef"),"TestID":6}
{"_id":ObjectId("4df6d56807444568af61cff0"),"TestID":7}
{"_id":ObjectId("4df6d56b07444568af61cff1"),"TestID":8}
{"_id":ObjectId("4df6d56e07444568af61cff2"),"TestID":9}
{"_id":ObjectId("4df6d57a07444568af61cff3"),"TestID":10}
{"_id":ObjectId("4df6d57d07444568af61cff4"),"TestID":11}
{"_id":ObjectId("4df6d58007444568af61cff5"),"TestID":12}
{"_id":ObjectId("4df6d58307444568af61cff6"),"TestID":13}
{"_id":ObjectId("4df6d58e07444568af61cff7"),"TestID":14}
{"_id":ObjectId("4df6d59207444568af61cff8"),"TestID":15}
{"_id":ObjectId("4df6d59607444568af61cff9"),"TestID":16}
{"_id":ObjectId("4df6d59c07444568af61cffa"),"TestID":17}
{"_id":ObjectId("4df6d5a307444568af61cffb"),"TestID":18}
{"_id":ObjectId("4df6d5a607444568af61cffc"),"TestID":19}
>DBQuery.shellBatchSize
20
>DBQuery.shellBatchSize=5
5
>db.Test.find()
{"_id":ObjectId("4df6d55407444568af61cfea"),"TestID":1}
{"_id":ObjectId("4df6d55907444568af61cfeb"),"TestID":2}
{"_id":ObjectId("4df6d55b07444568af61cfec"),"TestID":3}
{"_id":ObjectId("4df6d55e07444568af61cfed"),"TestID":4}
{"_id":ObjectId("4df6d56207444568af61cfee"),"TestID":5}
hasmore
>it
{"_id":ObjectId("4df6d56507444568af61cfef"),"TestID":6}
{"_id":ObjectId("4df6d56807444568af61cff0"),"TestID":7}
{"_id":ObjectId("4df6d56b07444568af61cff1"),"TestID":8}
{"_id":ObjectId("4df6d56e07444568af61cff2"),"TestID":9}
{"_id":ObjectId("4df6d57a07444568af61cff3"),"TestID":10}
hasmore
>it
{"_id":ObjectId("4df6d57d07444568af61cff4"),"TestID":11}
{"_id":ObjectId("4df6d58007444568af61cff5"),"TestID":12}
{"_id":ObjectId("4df6d58307444568af61cff6"),"TestID":13}
{"_id":ObjectId("4df6d58e07444568af61cff7"),"TestID":14}
{"_id":ObjectId("4df6d59207444568af61cff8"),"TestID":15}
hasmore
>it
{"_id":ObjectId("4df6d59607444568af61cff9"),"TestID":16}
{"_id":ObjectId("4df6d59c07444568af61cffa"),"TestID":17}
{"_id":ObjectId("4df6d5a307444568af61cffb"),"TestID":18}
{"_id":ObjectId("4df6d5a607444568af61cffc"),"TestID":19}
>it
nocursor

查询一条记录

>db.Account.findOne()
{
"_id":ObjectId("4ded95c3b7780a774a099b7c"),
"UserName":"libing",
"Password":"1",
"Email":"[e-mail]",
"RegisterDate":"2011-06-0711:06:25"
}

--SELECT TOP 1 * FROM Account

查询聚集中字段的不同记录

>db.Account.distinct("UserName")

--SELECT DISTINCT("UserName") FROM Account

查询聚集中UserName包含“keyword”关键字的记录

db.Account.find({"UserName":/keyword/})

--SELECT * FROM Account WHERE UserName LIKE '%keyword%'

查询聚集中UserName以"keyword" 开头的记录

>db.Account.find({"UserName":/^keyword/})

--SELECT * FROM Account WHERE UserName LIKE 'keyword%'

查询聚集中UserName以“keyword”结尾的记录

>db.Account.find({"UserName":/keyword$/})

--SELECT * FROM Account WHERE UserName LIKE '%keyword'

查询聚集中指定列

>db.Account.find({},{"UserName":1,"Email":1}) --1:true

--SELECT UserName,Email FROM Account

查询聚集中排除指定列

>db.Account.find({},{"UserName":0}) --0:false

查询聚集中指定列，且Age > 20

>db.Account.find({"Age":{"$gt":20}},{"UserName":1,"Email":1})

--SELECT UserName,Email FROM Account WHERE Age > 20

聚集中字段排序

>db.Account.find().sort({"UserName":1})--升序
>db.Account.find().sort({"UserName":-1})--降序

--SELECT * FROM Account ORDER BY UserName ASC

--SELECT * FROM Account ORDER BY UserName DESC

统计聚集中记录条数

>db.Account.find().count()

--SELECT COUNT(*) FROM Account

统计聚集中符合条件的记录条数

>db.Account.find({"Age":{"$gt":20}}).count()

-- SELECT COUNT(*) FROM Account WHERE Age > 20

统计聚集中字段符合条件的记录条数

>db.Account.find({"UserName":{"$exists":true}}).count()

--SELECT COUNT(UserName) FROM Account

查询聚集中前5条记录

>db.Account.find().limit(5)

--SELECT TOP 5 * FROM Account

查询聚集中第10条以后的记录

>db.Account.find().skip(10)

--SELECT * FROM Account WHERE AccountID NOT IN (SELECT TOP 10 AccountID FROM Account)

查询聚集中第10条记录以后的5条记录

>db.Account.find().skip(10).limit(5)

--SELECT TOP 5 * FROM Account WHERE AccountID NOT IN (SELECT TOP 10 AccountID FROM Account)

or查询

>db.Account.find({"$or":[{"UserName":/keyword/},{"Email":/keyword/}]},{"UserName":true,"Email":true})

--SELECT UserName,Email FROM Account WHERE UserName LIKE '%keyword%' OR Email LIKE '%keyword%'

添加新记录

>db.Account.insert({AccountID:2,UserName:"lb",Password:"1",Age:25,Email:"[e-mail]",RegisterDate:"2011-06-0916:36:95"})

修改记录

>db.Account.update({"AccountID":1},{"$set":{"Age":27,"Email":"[e-mail]"}})
>db.Account.find({"AccountID":1})
{"AccountID":1,"Age":27,"Email":"[e-mail]","Password":"1","RegisterDate":"2011-06-0916:31:25","UserName":"libing","_id":ObjectId("4df08553188e444d001a763a")}

>db.Account.update({"AccountID":1},{"$inc":{"Age":1}})
>db.Account.find({"AccountID":1})
{"AccountID":1,"Age":28,"Email":"[e-mail]","Password":"1","RegisterDate":"2011-06-0916:31:25","UserName":"libing","_id":ObjectId("4df08553188e444d001a763a")}

删除记录

>db.Account.remove({"AccountID":1})--DELETEFROMAccountWHEREAccountID=1

>db.Account.remove({"UserName":"libing"})--DELETEFROMAccountWHEREUserName='libing'

>db.Account.remove({"Age":{$lt:20}})--DELETEFROMAccountWHEREAge<20
>db.Account.remove({"Age":{$lte:20}})--DELETEFROMAccountWHEREAge<=20
>db.Account.remove({"Age":{$gt:20}})--DELETEFROMAccountWHEREAge>20
>db.Account.remove({"Age":{$gte:20}})--DELETEFROMAccountWHEREAge>=20
>db.Account.remove({"Age":{$ne:20}})--DELETEFROMAccountWHEREAge!=20

>db.Account.remove()--全部删除
>db.Account.remove({})--全部删除