查看全部数据表
switched to db ChatRoom
> show collections
Account
Chat
system.indexes
system.users
创建数据表
{ " 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
{ " ok " : 1 }
数据表帮助主题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
{ " _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 " }
说明:
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。
{ " _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
{
" _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
--SELECT DISTINCT("UserName") FROM Account
查询聚集中UserName包含“keyword”关键字的记录
--SELECT * FROM Account WHERE UserName LIKE '%keyword%'
查询聚集中UserName以"keyword" 开头的记录
--SELECT * FROM Account WHERE UserName LIKE 'keyword%'
查询聚集中UserName以“keyword”结尾的记录
--SELECT * FROM Account WHERE UserName LIKE '%keyword'
查询聚集中指定列
--SELECT UserName,Email FROM Account
查询聚集中排除指定列
查询聚集中指定列,且Age > 20
--SELECT UserName,Email FROM Account WHERE Age > 20
聚集中字段排序
> 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
--SELECT COUNT(*) FROM Account
统计聚集中符合条件的记录条数
-- SELECT COUNT(*) FROM Account WHERE Age > 20
统计聚集中字段符合条件的记录条数
--SELECT COUNT(UserName) FROM Account
查询聚集中前5条记录
--SELECT TOP 5 * FROM Account
查询聚集中第10条以后的记录
--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
--SELECT TOP 5 * FROM Account WHERE AccountID NOT IN (SELECT TOP 10 AccountID FROM Account)
or查询
--SELECT UserName,Email FROM Account WHERE UserName LIKE '%keyword%' OR Email LIKE '%keyword%'
添加新记录
修改记录
> 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.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({ " 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