mongodb学习笔记

去年接触了mongodb，跟关系数据库相比，在处理非结构化数据方面有很大的优点，特别是跟python的字典基本能无缝结合，整理了一些常用知识点，如下：

一、db操作
# 显示所有数据库列表
show dbs
# 连接到一个指定的数据库,若没有则直接创建
use dbname
# 删除数据库
db.dropDatabase()

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二、collection操作
collection对应mysql中的table

# 查看数据库中的所有集合
db.getCollectionNames() 
show collections
# 创建集合
db.createCollection("ios_group")
# 删除集合
db.userdetails.drop()
# 集合数据的条数
db.userdetails.count()
# 集合储存空间的大小
db.userdetails.storageSize()
# 创建一个集合
db.createCollection("collName", {size: 20, capped: 5, max: 100});
# 通过名称获取集合
db.getCollection("userdetails")
# 集合重命名
db.userInfo.renameCollection("users")
# 在集合中插入文档
db.userdetails.insert(document)
db.userdetails.insert({"user_id" : "user1","password" :"1a2b3c" ,"date_of_join" : "16/10/2010" ,"education" :"M.C.A.", "profession" : "CONSULTANT","interest" : "MUSIC","community_name" :["MODERN MUSIC", "CLASSICAL MUSIC","WESTERN MUSIC"],"community_moder_id" : ["MR. Alex","MR. Dang","MR Haris"],"community_members" : [700,200,1500],"friends_id" : ["kumar","harry","anand"],"ban_friends_id" :["Amir","Raja","mont"]});
db.userdetails.insert({"user_id" : "user2","password" :"11aa1a" ,"date_of_join" : "17/10/2009" ,"education" :"M.B.A." , "profession" : "MARKETING","interest" : "MUSIC","community_name" :["MODERN MUSIC", "CLASSICAL MUSIC","WESTERN MUSIC"],"community_moder_id" : ["MR. Roy","MR. Das","MR Doglus"],"community_members" : [500,300,1400],"friends_id" : ["pal","viki","john"],"ban_friends_id" :["jalan","monoj","evan"]});
db.userdetails.insert({"user_id" : "user3","password" :"b1c1d1" ,"date_of_join" : "16/10/2010" ,"education" :"M.C.A." , "profession" : "IT COR.","interest" : "ART","community_name" :["MODERN ART", "CLASSICAL ART","WESTERN ART"],"community_moder_id" : ["MR. Rifel","MR. Sarma","MR Bhatia"],"community_members" : [5000,2000,1500],"friends_id" : ["philip","anant","alan"],"ban_friends_id" :["Amir","Raja","mont"]});
db.userdetails.insert({"user_id" : "user4","password" :"abczyx" ,"date_of_join" : "17/8/2009" ,"education" :"M.B.B.S." , "profession" : "DOCTOR","interest" : "SPORTS","community_name" :["ATHELATIC", "GAMES FAN GYES","FAVOURIT GAMES"],"community_moder_id" : ["MR. Paul","MR. Das","MR Doglus"],"community_members" : [2500,2200,3500],"friends_id" : ["vinod","viki","john"],"ban_friends_id" :["jalan","monoj","evan"]});
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三、document操作

document对应mysql中的一条记录

# 新建文档
document=({"user_id" : "ABCDBWN","password" :"ABCDBWN"})
# 删除文档
db.userdetails.remove( { "user_id" : "testuser" } )
db.userdetails.remove({})

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四、查询操作

# 查询、条件查询
db.userdetails.find() 
db.userdetails.find({"education":"M.C.A."}) 
db.userdetails.distinct('user_id') 
db.testtable.find({age : {$gt : 22}}) 
# 查询指定列的内容+where条件 
db.userdetails.find({}, {user_id: 1, education: 1}); 
db.userdetails.find({age: {$gt: 25}}, {user_id: 1, education: 1}); 
# 条件or 
db.userInfo.find({$or: [{age: 22}, {age: 25}]}); 
# 按照age升序排列，-1=降序 
db.userInfo.find().sort({age: 1}); 
# 查询5~10条数据 
db.userInfo.find().limit(10).skip(5); 
# 修改数据name 
db.userdetails.update({age: 25}, {$set: {name: 'changeName'}}, false, true);