MongoDB数据表基本操作

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 " :  " [email protected] ",  " RegisterDate " :  " 2011-06-09 16:31:25 " }
{  " _id " : ObjectId( " 4df08586188e444d001a763b "),  " AccountID " : 2,  " UserName " :  " lb ",  " Password " :  " 1 ",  " Age " : 25,  " Email " :  " [email protected] ",  " 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 " :  " [email protected] ",
         " 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: " [email protected] ",RegisterDate: " 2011-06-09 16:36:95 "})

修改记录

> db.Account.update({ " AccountID ":1},{ " $set ":{ " Age ":27, " Email ": " [email protected] "}})
> db.Account.find({ " AccountID ":1})
{  " AccountID " : 1,  " Age " : 27,  " Email " :  " [email protected] ",  " 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 " :  " [email protected] ",  " 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