MongoDB数据表基本操作

原文地址为： 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

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