mongodb的基本操作

/usr/local/mongodb/bin/mongo#启动mongodb
MongoDB shell version: 2.2.6
connecting to: test

show dbs;#查看数据库
imooc 0.203125GB
local (empty)
use imooc_2#当没有imooc_2数据库时这个命令相当于创建了此数据库
switched to db imooc_2
show tables#查看数据库下的表
system.indexes
teacher

db.teacher.insert({‘name’:lilaoshi,age:24})#当imooc_2数据库没有teacher表时这个命令相当于创建了此表并插入数据
Sat Aug 29 20:54:09 ReferenceError: lilaoshi is not defined (shell):1#因为lilaoshi是字符串
db.teacher.insert({‘name’:’lilaoshi’,age:24})#插入
db.teacher.find();#查找（_id是mongodb的默认key）
{ “_id” : ObjectId(“55e1ab7ab6aebb3a7ca49928”), “name” : “lilaoshi”, “age” : 24 }

use imooc#进入imooc数据库
switched to db imooc
show tables;#查看数据库下的表
goods
imooc_collection
stu
system.indexes
tea
db.stu.count()#查看数据量
10000
db.stu.find({_id:3})
{ “_id” : 3, “sn” : “003”, “name” : “xiaoming3” }
db.stu.remove({_id:3})#删除数据根据_id删除
db.stu.find({_id:3})
db.stu.remove()#删除全部数据
db.stu.find()
db.stu.insert({_id:2,’name’:’xiaoming2’,age:21})
for(i=3;i<30;i++)db.stu.insert({_id:i,’name’:’xiaoming’+i,age:2+i})#用for插入多条
db.stu.find()
{ “_id” : 1, “name” : “xiaoming”, “age” : 20 }
{ “_id” : 2, “name” : “xiaoming2”, “age” : 21 }
{ “_id” : 3, “name” : “xiaoming3”, “age” : 5 }
db.stu.update({_id:2},{$set:{age:23}})#修改_id为2的age
db.stu.find()
{ “_id” : 1, “name” : “xiaoming”, “age” : 20 }
{ “_id” : 2, “name” : “xiaoming2”, “age” : 23 }

for(i=1;i<20;i++)db.stu.update({_id:i},{$set:{age:23}})#批量修改

db.stu.find()
{ “_id” : 1, “name” : “xiaoming”, “age” : 23 }
{ “_id” : 2, “name” : “xiaoming2”, “age” : 23 }
{ “_id” : 3, “name” : “xiaoming3”, “age” : 23 }
{ “_id” : 4, “name” : “xiaoming4”, “age” : 23 }
{ “_id” : 5, “name” : “xiaoming5”, “age” : 23 }

db.stu.help()#查看帮助
DBCollection help
db.stu.find().help() - show DBCursor help
db.stu.count()
db.stu.copyTo(newColl) - duplicates collection by copying all documents to newColl; no indexes are copied.
db.stu.convertToCapped(maxBytes) - calls {convertToCapped:’stu’, size:maxBytes}} command
db.stu.dataSize()
db.stu.distinct( key ) - e.g. db.stu.distinct( ‘x’ )
db.stu.drop() drop the collection
db.stu.dropIndex(index) - e.g. db.stu.dropIndex( “indexName” ) or db.stu.dropIndex( { “indexKey” : 1 } )
db.stu.dropIndexes()
db.stu.ensureIndex(keypattern[,options]) - options is an object with these possible fields: name, unique, dropDups
db.stu.reIndex()
db.stu.find([query],[fields]) - query is an optional query filter. fields is optional set of fields to return.
e.g. db.stu.find( {x:77} , {name:1, x:1} )
db.stu.find(…).count()
db.stu.find(…).limit(n)
db.stu.find(…).skip(n)
db.stu.find(…).sort(…)
db.stu.findOne([query])
db.stu.findAndModify( { update : … , remove : bool [, query: {}, sort: {}, ‘new’: false] } )
db.stu.getDB() get DB object associated with collection
db.stu.getIndexes()
db.stu.group( { key : …, initial: …, reduce : …[, cond: …] } )
db.stu.insert(obj)
db.stu.mapReduce( mapFunction , reduceFunction , )
db.stu.remove(query)
db.stu.renameCollection( newName , ) renames the collection.
db.stu.runCommand( name , ) runs a db command with the given name where the first param is the collection name
db.stu.save(obj)
db.stu.stats()
db.stu.storageSize() - includes free space allocated to this collection
db.stu.totalIndexSize() - size in bytes of all the indexes
db.stu.totalSize() - storage allocated for all data and indexes
db.stu.update(query, object[, upsert_bool, multi_bool]) - instead of two flags, you can pass an object with fields: upsert, multi
db.stu.validate( ) - SLOW
db.stu.getShardVersion() - only for use with sharding
db.stu.getShardDistribution() - prints statistics about data distribution in the cluster
db.stu.getSplitKeysForChunks( ) - calculates split points over all chunks and returns splitter function