MongoDB数据表基本操作

查看全部数据表

> use ChatRoom

switched to db ChatRoom

> show collections

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()

DBCollection help

db.Account.find().help() - show DBCursor help

db.Account.count()

db.Account.dataSize()

db.Account.distinct( key ) - eg. db.Account.distinct( 'x' )

db.Account.drop() drop the collection

db.Account.dropIndex(name)

db.Account.dropIndexes()

db.Account.ensureIndex(keypattern[,options]) - options is an object with these possible fields: name, unique, dropDups

db.Account.reIndex()

db.Account.find([query],[fields]) - query is an optional query filter. fields is optional set of fields to return.

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() get DB object associated with collection

db.Account.getIndexes()

db.Account.group( { key : ..., initial: ..., reduce : ...[, cond: ...] } )

db.Account.mapReduce( mapFunction , reduceFunction , <optional params> )

db.Account.remove(query)

db.Account.renameCollection( newName , <dropTarget> ) renames the collection.

db.Account.runCommand( name , <options> ) runs a db command with the given name where the first param is the collection name

db.Account.save(obj)

db.Account.stats()

db.Account.storageSize() - includes free space allocated to this collection

db.Account.totalIndexSize() - size in bytes of all the indexes

db.Account.totalSize() - storage allocated for all data and indexes

db.Account.update(query, object[, upsert_bool, multi_bool])

db.Account.validate() - SLOW

db.Account.getShardVersion() - only for use with sharding

查看全部表记录

> db.Account.find()

{ "_id" : ObjectId("4df08553188e444d001a763a"), "AccountID" : 1, "UserName" : "libing", "Password" : "1", "Age" : 26, "Email" : "libing@126.com", "RegisterDate" : "2011-06-09 16:31:25" }

{ "_id" : ObjectId("4df08586188e444d001a763b"), "AccountID" : 2, "UserName" : "lb", "Password" : "1", "Age" : 25, "Email" : "libing@163.com", "RegisterDate" : "2011-06-09 16:36:95" }

--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 }
has more
> 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 }
has more
> 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 }
has more
> it
{ "_id" : ObjectId("4df6d59607444568af61cff9"), "TestID" : 16 }
{ "_id" : ObjectId("4df6d59c07444568af61cffa"), "TestID" : 17 }
{ "_id" : ObjectId("4df6d5a307444568af61cffb"), "TestID" : 18 }
{ "_id" : ObjectId("4df6d5a607444568af61cffc"), "TestID" : 19 }
> it
no cursor

查询一条记录

> db.Account.findOne()
{
"_id" : ObjectId("4ded95c3b7780a774a099b7c"),
"UserName" : "libing",
"Password" : "1",
"Email" : "libing@126.cn",
"RegisterDate" : "2011-06-07 11:06:25"
}--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:"libing@163.com",RegisterDate:"2011-06-09 16:36:95"})

修改记录

> db.Account.update({"AccountID":1},{"$set":{"Age":27,"Email":"libingql@163.com"}})

> db.Account.find({"AccountID":1})

{ "AccountID" : 1, "Age" : 27, "Email" : "libingql@163.com", "Password" : "1", "RegisterDate" : "2011-06-09 16:31:25", "UserName" : "libing", "_id" : ObjectId("4df08553188e444d001a763a") }

> db.Account.update({"AccountID":1},{"$inc":{"Age":1}})

> db.Account.find({"AccountID":1})

{ "AccountID" : 1, "Age" : 28, "Email" : "libingql@163.com", "Password" : "1", "RegisterDate" : "2011-06-09 16:31:25", "UserName" : "libing", "_id" : ObjectId("4df08553188e444d001a763a") }

删除记录

> db.Account.remove({"AccountID":1}) --DELETE FROM Account WHERE AccountID = 1

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

> db.Account.remove({"Age":{$lt:20}}) --DELETE FROM Account WHERE Age < 20

> db.Account.remove({"Age":{$lte:20}}) --DELETE FROM Account WHERE Age <= 20

> db.Account.remove({"Age":{$gt:20}}) --DELETE FROM Account WHERE Age > 20

> db.Account.remove({"Age":{$gte:20}}) --DELETE FROM Account WHERE Age >= 20

> db.Account.remove({"Age":{$ne:20}}) --DELETE FROM Account WHERE Age != 20

> db.Account.remove() --全部删除

> db.Account.remove({}) --全部删除