mongodb的简单操作
{name:"MongoDB", type:"NoSQL"}####关于NoSQL
1.什么是NoSQL
NoSQL，指非关系型的数据库。No> 2.为什么要使用NoSQL(http://robbin.iteye.com/blog/524977)
对数据库的“三高”需求:
1.高并发读写
2.对海量数据的高效率读写
3.高扩展性和高可用性
关系型数据库的特性地位下降:
1.事务一致性
2.读写实时性
3.复杂SQL，特别是多表关联查询
对自己来说学习的目的主要是跟风，囧，很多招聘信息都要求熟悉MongoDB，个人的项目也无法体会到上面所说的优势，也体会不出关系型数据库的劣势，一个sqlite就可以让我的项目跑的风吼。不过，趁着年轻，多学一点。
####MongoDB简单操作(文档：http://cn.docs.mongodb.org/manual/)
######在Ubuntu上安装MongoDB:
1.`sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 7F0CEB10`
2.`echo "deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen" >> /etc/apt/sources.list.d/10gen.list`
3.`sudo apt-get update`
4.`apt-get install mongodb-10gen`
配置文件:/etc/mongodb.conf
默认数据文件位置:/var/lib/mongodb
默认日志文件位置:/var/log/mongodb
默认监听端口:27017
HTTP服务端口:监听端口+1000(http://localhost:28017)
http://t1.qpic.cn/mblogpic/d237f53b5a0275b8a408/2000.jpg
默认web接口是不能使用里面的功能的，使用web接口要先建数据库目录，修改对象操作权限，再用对应参数如：--rest启动mongod
ashin@linux:~$ sudo mkdir -p /data/db
ashin@linux:~$ sudo chmod 777 /data/db
ashin@linux:~$ mongod --rest
######开启与停止服务:
开启：`sudo service mongodb start`
停止：`sudo service mongodb stop`
重启：`sudo service mongodb restart`
运行javascript shell：`mongo` (help命令可以查看帮助信息)
http://t1.qpic.cn/mblogpic/37710f67ca86110df64a/2000.jpg
MongoDB用文档保存数据(键/值)：{"name":"ashin"}
键不能含有\0,它表示键的结尾，.和$还有_均为保留符号。
多个文档组成集合（集合类似于表，文档类似于行），多个集合组成数据库。
进入shell默认连接的是test数据库，使用db命令可以查看当前正在使用的数据库，use DATABASENAME可以切换使用的数据库。使用show collections可以查看当前数据库有哪些集合。文档可以套嵌，值可以为数组，用{'key':}表示。
######简单CRUD：
> db //显示当前连接的数据库
test
> show collections//显示数据库中所有集合
system.indexes
test
things
> birthday = {'year':1992, 'month':12, 'day':26} //创建文档
{ "year" : 1992, "month" : 12, "day" : 26 }
> db.ak.insert(birthday) //把文档加入到ak集合中，ak集合在数据库中被创建
> show collections
ak
system.indexes
test
things
> db.ak.find()//查询集合中所有文档，Id的值由时间戳+机器+PID+计数器组成。
{ "_id" : ObjectId("51518c97862ecf1b9f562459"), "year" : 1992, "month" : 12, "day" : 26 }
> birthday.name="dog"
dog
> db.ak.update({'year':1992}, birthday) //更新修改文档
> db.ak.find()
{ "_id" : ObjectId("51518c97862ecf1b9f562459"), "year" : 1992, "month" : 12, "day" : 26, "name" : "dog" }
> db.ak.remove({"name":"dog"})//删除文档
> db.ak.find()
>
> dog={'sex':'F'}
{ "sex" : "F" }
> dog.birthday = birthday
{ "year" : 1992, "month" : 12, "day" : 26, "name" : "dog" }
> dog //套嵌文档
{
"sex" : "F",
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
}
}
> dog.food = ['shit', 'maidong'] //使用数组
[ "shit", "maidong" ]
> dog.today = new Date() //使用日期
ISODate("2013-03-26T12:17:17.045Z")
> dog
{
"sex" : "F",
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"shit",
"maidong"
],
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
>
######更新文档：
$inc:对某个键的值加上指定的数
> db.ak.insert(dog)
> db.ak.update({"birthday.year":1992}, {"$inc":{"birthday.day":2}})
> db.ak.findOne()
{
"_id" : ObjectId("5151959f862ecf1b9f56245a"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 28, //26+2
"name" : "dog"
},
"food" : [
"shit",
"maidong"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
$set:指定一个键的值，不存在则创建它
$unset:删除某个键
> db.ak.findOne({"birthday.day":28})
{
"_id" : ObjectId("5151959f862ecf1b9f56245a"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 28,
"name" : "dog"
},
"day" : 2,//birthday.day写成了day造成的
"food" : [
"shit",
"maidong"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
> db.ak.update({"birthday.day":28}, {"$set":{"name":"cookie"}}) //添加/修改键的值
> db.ak.findOne({"birthday.day":28})
{
"_id" : ObjectId("5151959f862ecf1b9f56245a"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 28,
"name" : "dog"
},
"day" : 2,
"food" : [
"shit",
"maidong"
],
"name" : "cookie",
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
> db.ak.update({"birthday.day":28}, {"$unset":{"day":1}}) //删除指定键
> db.ak.findOne({"birthday.day":28})
{
"_id" : ObjectId("5151959f862ecf1b9f56245a"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 28,
"name" : "dog"
},
"food" : [
"shit",
"maidong"
],
"name" : "cookie",
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
>
$push:增加到数组
$ne:不等于，不含有
> db.ak.update({"food" : {"$ne":"egg"}}, {"$push":{"food":"wow"}})//在food中不包含egg的文档中向food中加入wow
> db.ak.find()
{ "_id" : ObjectId("5151959f862ecf1b9f56245a"), "birthday" : { "year" : 1992, "month" : 12, "day" : 28, "name" : "dog" }, "food" : [ "shit", "maidong","moliqingcha","moliqingcha","maijie", "maijie", "egg" ], "name" : "cookie", "sex" : "F", "today" : ISODate("2013-03-26T12:17:17.045Z") }
{ "_id" : ObjectId("51519644862ecf1b9f56245b"), "birthday" : { "year" : 1992, "month" : 12, "day" : 26, "name" : "dog" }, "food" : [ "shit", "maidong", "maijie", "maijie", "wahaha", "wahaha", "wow" ], "sex" : "F", "today" : ISODate("2013-03-26T12:17:17.045Z") }
>
$addToSet:添加到集合，确保不重复
> db.ak.update({"_id":ObjectId("51519644862ecf1b9f56245b")}, {"$addToSet":{"food":"pizza"}}) //添加到set
> db.ak.findOne({"_id":ObjectId("51519644862ecf1b9f56245b")})
{
"_id" : ObjectId("51519644862ecf1b9f56245b"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"shit",
"maidong",
"maijie",
"maijie",
"wahaha",
"wahaha",
"wow",
"pizza"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
> db.ak.update({"_id":ObjectId("51519644862ecf1b9f56245b")}, {"$addToSet":{"food":"pizza"}} ) //再次添加不会被添加
> db.ak.findOne({"_id":ObjectId("51519644862ecf1b9f56245b")})
{
"_id" : ObjectId("51519644862ecf1b9f56245b"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"shit",
"maidong",
"maijie",
"maijie",
"wahaha",
"wahaha",
"wow",
"pizza"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
>
$each:[]:对数组中每个元素执行前面的操作
> db.ak.update({"_id":ObjectId("51519644862ecf1b9f56245b")}, {"$addToSet":{"food":["pizza1","pizza2"]}} ) //为food添加一个数组
> db.ak.findOne({"_id":ObjectId("51519644862ecf1b9f56245b")})
{
"_id" : ObjectId("51519644862ecf1b9f56245b"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"shit",
"maidong",
"maijie",
"maijie",
"wahaha",
"wahaha",
"wow",
"pizza",
[
"pizza1",
"pizza2"
]
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
> db.ak.update({"_id":ObjectId("51519644862ecf1b9f56245b")}, {"$addToSet":{"food":{"$each":["pizza1","pizza2"]}}} ) //$each将每个值添加到food数组中
> db.ak.findOne({"_id":ObjectId("51519644862ecf1b9f56245b")})
{
"_id" : ObjectId("51519644862ecf1b9f56245b"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"shit",
"maidong",
"maijie",
"maijie",
"wahaha",
"wahaha",
"wow",
"pizza",
[
"pizza1",
"pizza2"
],
"pizza1",
"pizza2"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
>
$pop:删除数组任意一端的元素
> db.ak.update({"_id":ObjectId("51519644862ecf1b9f56245b")}, {"$pop":{"food":1}} )//删除food的最后一个元素
> db.ak.findOne({"_id":ObjectId("51519644862ecf1b9f56245b")})
{
"_id" : ObjectId("51519644862ecf1b9f56245b"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"shit",
"maidong",
"maijie",
"maijie",
"wahaha",
"wahaha",
"wow",
"pizza",
[
"pizza1",
"pizza2"
],
"pizza1"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
> db.ak.update({"_id":ObjectId("51519644862ecf1b9f56245b")}, {"$pop":{"food":-1}} ) //删除food的第一个元素
> db.ak.findOne({"_id":ObjectId("51519644862ecf1b9f56245b")})
{
"_id" : ObjectId("51519644862ecf1b9f56245b"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"maidong",
"maijie",
"maijie",
"wahaha",
"wahaha",
"wow",
"pizza",
[
"pizza1",
"pizza2"
],
"pizza1"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
>
数组下标定位
> db.ak.update({"_id":ObjectId("51519644862ecf1b9f56245b")}, {"$set":{"food.1":"maijie2"}}) //修改food的第二个元素
> db.ak.findOne({"_id":ObjectId("51519644862ecf1b9f56245b")})
{
"_id" : ObjectId("51519644862ecf1b9f56245b"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"maidong",
"maijie2",
"maijie",
"wahaha",
"wahaha",
"wow",
"pizza",
[
"pizza1",
"pizza2"
],
"pizza1"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
> db.ak.update({"_id":ObjectId("51519644862ecf1b9f56245b")}, {"$set":{"food.7.0":"pizza0"}}) //修改food第8个元素的第一个值
> db.ak.findOne({"_id":ObjectId("51519644862ecf1b9f56245b")})
{
"_id" : ObjectId("51519644862ecf1b9f56245b"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 26,
"name" : "dog"
},
"food" : [
"maidong",
"maijie2",
"maijie",
"wahaha",
"wahaha",
"wow",
"pizza",
[
"pizza0",
"pizza2"
],
"pizza1"
],
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
>
upsert:update函数第三个参数指定为true表示upsert，即如果要更新的文档存在则正常更新，不存在就新创建。
> db.ak.update({"birthday.day":29}, {"$inc":{"day":1}}) //普通update不存在的文档不会有变化
> db.ak.find()
{ "_id" : ObjectId("5151959f862ecf1b9f56245a"), "birthday" : { "year" : 1992, "month" : 12, "day" : 28, "name" : "dog" }, "food" : [ "shit", "maidong","moliqingcha","moliqingcha","maijie", "maijie", "egg" ], "name" : "cookie", "sex" : "F", "today" : ISODate("2013-03-26T12:17:17.045Z") }
{ "_id" : ObjectId("51519644862ecf1b9f56245b"), "birthday" : { "year" : 1992, "month" : 12, "day" : 26, "name" : "dog" }, "food" : [ "maidong","maijie2","maijie", "wahaha", "wahaha", "wow","pizza", [ "pizza0", "pizza2" ], "pizza1" ], "sex" : "F", "today" : ISODate("2013-03-26T12:17:17.045Z") }
> db.ak.update({"birthday.day":29}, {"$inc":{"day":1}}, true) //upsert更新则会创建新文档
> db.ak.find()
{ "_id" : ObjectId("5151959f862ecf1b9f56245a"), "birthday" : { "year" : 1992, "month" : 12, "day" : 28, "name" : "dog" }, "food" : [ "shit", "maidong","moliqingcha","moliqingcha","maijie", "maijie", "egg" ], "name" : "cookie", "sex" : "F", "today" : ISODate("2013-03-26T12:17:17.045Z") }
{ "_id" : ObjectId("51519644862ecf1b9f56245b"), "birthday" : { "year" : 1992, "month" : 12, "day" : 26, "name" : "dog" }, "food" : [ "maidong","maijie2","maijie", "wahaha", "wahaha", "wow","pizza", [ "pizza0", "pizza2" ], "pizza1" ], "sex" : "F", "today" : ISODate("2013-03-26T12:17:17.045Z") }
{ "_id" : ObjectId("51525958265b2c47d47147d3"), "birthday" : { "day" : 29 }, "day" : 1 }
>
save：文档不存在则插入，存在就修改
> dog=db.ak.findOne()
{
"_id" : ObjectId("5151959f862ecf1b9f56245a"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 28,
"name" : "dog"
},
"food" : [
"shit",
"maidong",
"moliqingcha",
"moliqingcha",
"maijie",
"maijie",
"egg"
],
"name" : "cookie",
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z")
}
> dog.color = "gold"
gold
> db.ak.save(dog)
> dog=db.ak.findOne()
{
"_id" : ObjectId("5151959f862ecf1b9f56245a"),
"birthday" : {
"year" : 1992,
"month" : 12,
"day" : 28,
"name" : "dog"
},
"food" : [
"shit",
"maidong",
"moliqingcha",
"moliqingcha",
"maijie",
"maijie",
"egg"
],
"name" : "cookie",
"sex" : "F",
"today" : ISODate("2013-03-26T12:17:17.045Z"),
"color" : "gold"
}
>
更新多个文档：
默认更新只对符合匹配的第一个文档执行操作，要修改所有符合匹配的文档进行操作需要设置update的第四个参数为true
> db.things.find()
{ "_id" : ObjectId("51512cf4c3bb8082f1b65193"), "x" : 4, "j" : 1 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "x" : 4, "j" : 2 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "x" : 4, "j" : 3 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "x" : 4, "j" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "x" : 4, "j" : 5 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "x" : 4, "j" : 6 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "x" : 4, "j" : 7 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "x" : 4, "j" : 8 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519b"), "x" : 4, "j" : 9 }
> db.things.update({"x":4}, {"$set":{"k":0}})
> db.things.find()
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "x" : 4, "j" : 2 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "x" : 4, "j" : 3 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "x" : 4, "j" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "x" : 4, "j" : 5 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "x" : 4, "j" : 6 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "x" : 4, "j" : 7 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "x" : 4, "j" : 8 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519b"), "x" : 4, "j" : 9 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65193"), "j" : 1, "k" : 0, "x" : 4 } //只更新了j=1
> db.things.update({"x":4}, {"$set":{"k":0}}, false, true)
> db.things.find()//全部更新
{ "_id" : ObjectId("51512cf4c3bb8082f1b65193"), "j" : 1, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519b"), "j" : 9, "k" : 0, "x" : 4 }
>
更新并返回文档：
普通的update更新后不会有返回值，可以通过findAndModify命令来做
> db.runCommand({"findAndModify":"things","query":{"x":4},"sort":{"j":-1}, "update":{"$inc":{"k":1}}})
{
"lastErrorObject" : {
"updatedExisting" : true,
"n" : 1,
"connectionId" : 5,
"err" : null,
"ok" : 1
},
"value" : {
"_id" : ObjectId("51512cf4c3bb8082f1b6519b"),
"j" : 9,
"k" : 0,
"x" : 4
},
"ok" : 1
}
> db.things.find()
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519b"), "j" : 9, "k" : 1, "x" : 4 }
> db.runCommand({"findAndModify":"things","query":{"x":4},"sort":{"j":-1}, "update":{"$inc":{"k":1}}}).value
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519b"), "j" : 9, "k" : 1, "x" : 4 }
> db.things.find()
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519b"), "j" : 9, "k" : 2, "x" : 4 }
> db.runCommand({"findAndModify":"things","query":{"k":2},"sort":{"j":1}, "remove":true}).value
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519b"), "j" : 9, "k" : 2, "x" : 4 }
> db.things.find()
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
>
######查询
find():默认传递{}参数，{}匹配集合的全部内容
find({}, {'key1':1, "key2":1}):只返回第二个参数指定的键，_id总是被返回
> db.things.find({}, {'k':1})
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "k" : 0 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "k" : 0 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "k" : 0 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "k" : 0 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "k" : 0 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "k" : 0 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "k" : 0 }
> db.things.find({}, {'k':1, '_id':0})
{ "k" : 0 }
{ "k" : 0 }
{ "k" : 0 }
{ "k" : 0 }
{ "k" : 0 }
{ "k" : 0 }
{ "k" : 0 }
查询条件：
"$lt", "$lte", "$gt", "$gte", "$ne", "$in", "$nin", "$or", "$not", "$mod"
> db.things.find({"j":{"$gte":3, "$lte":7}})
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
>
> db.things.find({"j":{"$in":}})
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
> db.things.find({"j":{"$nin":}})
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
> db.things.find({"j":{"$mod":}})//将查询的值除以第一个给定值，余数为第二个给定值则返回结果
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
> db.things.find({"j":{"$not":{"$mod":}}})
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
>
正则表达式：
> db.things.find()
{ "_id" : ObjectId("51526f5af1085f80823f7344"), "j" : "hello" }
{ "_id" : ObjectId("515270a7f1085f80823f7346"), "j" : "1hello" }
> db.things.find({"j":/hello/})
{ "_id" : ObjectId("51526f5af1085f80823f7344"), "j" : "hello" }
{ "_id" : ObjectId("515270a7f1085f80823f7346"), "j" : "1hello" }
> db.things.find({"j":/^hello/})
{ "_id" : ObjectId("51526f5af1085f80823f7344"), "j" : "hello" }
>
查询数组：
> db.array.insert({'a':})
> db.array.insert({'a':})
> db.array.insert({'a':})
> db.array.find({"a":})
> db.array.find({"a":{"$all":}})//通过多个元素来匹配数组必须用$all
{ "_id" : ObjectId("515272d9f1085f80823f7349"), "a" : [ 1, 2, 3 ] }
{ "_id" : ObjectId("515272dff1085f80823f734a"), "a" : [ 2, 3, 4 ] }
{ "_id" : ObjectId("515272e2f1085f80823f734b"), "a" : [ 2, 3, 1 ] }
> db.array.find({"a":}) //准确匹配，与位置有关
{ "_id" : ObjectId("515272d9f1085f80823f7349"), "a" : [ 1, 2, 3 ] }
> db.array.find({"a":[2,1,3rray.find({},{"a":{"$slice":2}}) //返回前2个元素
{ "_id" : ObjectId("515272d9f1085f80823f7349"), "a" : [ 1, 2 ] }
{ "_id" : ObjectId("515272dff1085f80823f734a"), "a" : [ 2, 3 ] }
{ "_id" : ObjectId("515272e2f1085f80823f734b"), "a" : [ 2, 3 ] }
> db.array.find({},{"a":{"$slice":-2}}) //返回后2个元素
{ "_id" : ObjectId("515272d9f1085f80823f7349"), "a" : [ 2, 3 ] }
{ "_id" : ObjectId("515272dff1085f80823f734a"), "a" : [ 3, 4 ] }
{ "_id" : ObjectId("515272e2f1085f80823f734b"), "a" : [ 3, 1 ] }
> db.array.find({},{"a":{"$slice":}})//返回第1个到第2个元素
{ "_id" : ObjectId("515272d9f1085f80823f7349"), "a" : [ 1, 2 ] }
{ "_id" : ObjectId("515272dff1085f80823f734a"), "a" : [ 2, 3 ] }
{ "_id" : ObjectId("515272e2f1085f80823f734b"), "a" : [ 2, 3 ] }
$where执行任意javascript作为查询：
> db.things.find({"$where":function(){
... for (i in this){
... for (j in this){
... if (i!=j && this == this){ //查找键不同但值相同的元素
... return true;
... }
... }
... }
... }})
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
>
游标：
> var c = db.things.find(); //必须用var声明
> c.hasNext()
true
> while (c.hasNext()){
... printjson(c.next())
... }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51526f5af1085f80823f7344"), "j" : "hello" }
{ "_id" : ObjectId("515270a7f1085f80823f7346"), "j" : "1hello" }
> db.things.find().limit(2) //指定返回个数上限
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
> db.things.find().skip(2)//略过指定个数
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51526f5af1085f80823f7344"), "j" : "hello" }
{ "_id" : ObjectId("515270a7f1085f80823f7346"), "j" : "1hello" }
> db.things.find().sort({'j':-1}) //1升序，-1降序
{ "_id" : ObjectId("51526f5af1085f80823f7344"), "j" : "hello" }
{ "_id" : ObjectId("515270a7f1085f80823f7346"), "j" : "1hello" }
{ "_id" : ObjectId("51512cf4c3bb8082f1b6519a"), "j" : 8, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65199"), "j" : 7, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65198"), "j" : 6, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65197"), "j" : 5, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65196"), "j" : 4, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65195"), "j" : 3, "k" : 0, "x" : 4 }
{ "_id" : ObjectId("51512cf4c3bb8082f1b65194"), "j" : 2, "k" : 0, "x" : 4 }
>
聚合：
> db.array.find()
{ "_id" : ObjectId("515272d9f1085f80823f7349"), "a" : [ 1, 2, 3 ] }
{ "_id" : ObjectId("515272dff1085f80823f734a"), "a" : [ 2, 3, 4 ] }
{ "_id" : ObjectId("515272e2f1085f80823f734b"), "a" : [ 2, 3, 1 ] }
> db.array.count()
3
> db.array.count({"a":})
1
> db.runCommand({"distinct":"array", "key":"a"})
{
"values" : [
1,
2,
3,
4
],
"stats" : {
"n" : 3,
"nscanned" : 3,
"nscannedObjects" : 3,
"timems" : 0,
"cursor" : "BasicCursor"
},
"ok" : 1
}
分组：
> db.testgroup.find()
{ "_id" : ObjectId("5157937e12ebc6d285bdf6c1"), "ka" : 1, "kb" : 2 }
{ "_id" : ObjectId("5157938512ebc6d285bdf6c2"), "ka" : 1, "kb" : 1 }
{ "_id" : ObjectId("5157938912ebc6d285bdf6c3"), "ka" : 1, "kb" : 1 }
{ "_id" : ObjectId("5157938f12ebc6d285bdf6c4"), "ka" : 1, "kb" : 1 }
{ "_id" : ObjectId("5157939512ebc6d285bdf6c5"), "ka" : 1, "kb" : 1 }
> db.testgroup.group({
"key":{"kb":1},
"initial":{count:0},
"reduce":function(currdoc, prevdoc){
prevdoc.count+=currdoc.ka }
})
[ { "kb" : 2, "count" : 1 }, { "kb" : 1, "count" : 4 } ]
>
initial文档在reduce执行时，会作为初始文档传递给后续过程作为累加器文档，最后返回这个initial文档。
reduce中系统会传递两个参数，当前文档和累加器文档。
GridFS:
GridFS用来存放大二进制文件
ashin@linux:~$ ls
diskmongodb-note.txtopenshifttestVirtualBox VMsWallpaperworkspace公共的模板视频图片文档下载音乐桌面
ashin@linux:~$ mongofiles put mongodb-note.txt
connected to: 127.0.0.1
added file: { _id: ObjectId('51579c73e0af6265ff63802d'), filename: "mongodb-note.txt", chunkSize: 262144, uploadDate: new Date(1364696179568), md5:"6cd61341da1784b37e692c862ef4be45", length: 30615 }
done!
ashin@linux:~$ rm mongodb-note.txt
ashin@linux:~$ ls
diskopenshifttestVirtualBox VMsWallpaperworkspace公共的模板视频图片文档下载音乐桌面
ashin@linux:~$ mongofiles get mongodb-note.txt
connected to: 127.0.0.1
done write to: mongodb-note.txt
ashin@linux:~$ ls
diskmongodb-note.txtopenshifttestVirtualBox VMsWallpaperworkspace公共的模板视频图片文档下载音乐桌面
ashin@linux:~$
####主从复制
主从复制可用于备份、故障恢复、读扩展等。设置一个主节点，多个从节点，从节点就可以复制主节点的数据到本地。
在linux上的2612端口建一个主节点并设置为自动同步：`mongod --dbpath ./mongo/dbs/master/ --port 2612 --master --autoresync`
在windows上7474端口建个从节点：`mongod.exe --dbpath c:\data\db --port 7474 --slave --source 192.168.2.130:2612`
现在在主节点上添加数据，可以看到后台在打印同步信息，完成后到windows下去看，和主节点上的数据一样了。如果在从节点上添加数据的话，会提示not master。以从节点的身份运行mongo shell貌似不能连接上数据库，改成独立的mongod服务运行就好了。
####副本集
副本集是有自动故障恢复功能的主从集群，区别是副本集没有固定的主节点。
在192.168.2.130上创建数据库：`mongod --dbpath test/mongo/dbs/node2/ --port 10002 --replSet imsetname/192.168.2.108:10001`
在192.168.2.108上创建数据库：`mongod --dbpath test/mongo/dbs/node1/ --port 10001 --replSet imsetname/192.168.2.130:10002`
连接数据库初始化服务器：
`mongo 192.168.2.130:10002/admin`
> db.runCommand({"replSetInitiate":{
... "_id":"imsetname",
... "members":[
... {
... "_id":1,
... "host":"192.168.2.130:10002"
... },
... {
... "_id":2,
... "host":"192.168.2.108:10001"
... }
... ]}})
{
"info" : "Config now saved locally.Should come online in about a minute.",
"ok" : 1
}
进入数据库提示符变为：`imsetname:PRIMARY> `表示是master节点，可以进行操作，断开再次连接发现提示符变成：`imsetname:SECONDARY> `，再进行操作会提示错误信息。master节点是不确定的，它由其他节点选举出来。读扩展可以放在从节点上查询减轻主节点负载。
####分片
将数据库集合拆分，分散存在不同的机器上，mongodb可以自动进行分片。运行一个mongos路由进程，它知道所有数据存放的位置。
启动配置服务器：
ashin@linux:~/test/mongo$ mkdir dbs/config
ashin@linux:~/test/mongo$ mongod. --dbpath ./dbs/config --port 2612
建立mongos进程：
ashin@linux:~/test/mongo$ mongos --port 2712 --configdb localhost:2612 添加分片（普通的mongod实例或副本集）：
ashin@linux:~/test/mongo$ mkdir dbs/shard1
ashin@linux:~/test/mongo$ mongod--dbpath dbs/shard1 --port 7777
ashin@linux:~/test/mongo$ mkdir dbs/shard2
ashin@linux:~/test/mongo$ mongod--dbpath dbs/shard2 --port 7778
连接mongos，为集群添加片：
ashin@linux:~/test/mongo$ mongo localhost:2712/admin
MongoDB shell version: 2.4.1
connecting to: localhost:2712/admin
mongos> db.runCommand({
... addshard:"localhost:7777",
... allowLocal:true //在localhost上运行片，生产环境中集群部署在不同的机器上
... })
{ "shardAdded" : "shard0000", "ok" : 1 }
mongos> db.runCommand({
... addshard:"localhost:7778",
... allowLocal:true
... })
{ "shardAdded" : "shard0001", "ok" : 1 }
切分数据：
mongos> db.runCommand({"enablesharding":"shardtest"}) //将shardtest数据库的分片功能打开
{ "ok" : 1 }
mongos> db.runCommand({"shardcollection":"shardtest.hehe", "key":{"_id":1}}) //对hehe集合按照_id来分片。
{ "collectionsharded" : "shardtest.hehe", "ok" : 1 }
管理分片：
mongos> use config//切换到config数据库
switched to db config
mongos> db.shards.find() //查询分片
{ "_id" : "shard0000", "host" : "localhost:7777" }
{ "_id" : "shard0001", "host" : "localhost:7778" }
mongos> db.databases.find() //查询已经在片上的数据库信息，partitioned表示是否启用分片功能，primary表示数据库最开始创建数据文件的位置
{ "_id" : "admin", "partitioned" : false, "primary" : "config" }
{ "_id" : "test", "partitioned" : false, "primary" : "shard0000" }
{ "_id" : "shardtest", "partitioned" : true, "primary" : "shard0000" }
mongos> db.chunks.find() //块信息
{ "_id" : "shardtest.hehe-_id_MinKey", "lastmod" : { "t" : 1, "i" : 0 }, "lastmodEpoch" : ObjectId("51592a6afbb6a0314bd6a9c7"), "ns" : "shardtest.hehe", "min" : { "_id" : { "$minKey" : 1 } }, "max" : { "_id" : { "$maxKey" : 1 } }, "shard" : "shard0000" }
mongos> db.printShardingStatus() //显示所有概要信息
--- Sharding Status ---
sharding version: {
"_id" : 1,
"version" : 3,
"minCompatibleVersion" : 3,
"currentVersion" : 4,
"clusterId" : ObjectId("51592728fbb6a0314bd6a939")
}
shards:
{"_id" : "shard0000","host" : "localhost:7777" }
{"_id" : "shard0001","host" : "localhost:7778" }
databases:
{"_id" : "admin","partitioned" : false,"primary" : "config" }
{"_id" : "test","partitioned" : false,"primary" : "shard0000" }
{"_id" : "shardtest","partitioned" : true,"primary" : "shard0000" }
shardtest.hehe
shard key: { "_id" : 1 }
chunks:
shard00001
{ "_id" : { "$minKey" : 1 } } -->> { "_id" : { "$maxKey" : 1 } } on : shard0000 { "t" : 1, "i" : 0 }
mongos> use admin //删除分片
switched to db admin
mongos> db.runCommand({"removeshard":"localhost:7777"})
{
"msg" : "draining started successfully",
"state" : "started",
"shard" : "shard0000",
"note" : "you need to drop or movePrimary these databases",
"dbsToMove" : [
"shardtest",
"test"
],
"ok" : 1
}
先在mongos中插入数据后，在7777上可以查到，7778上没有数据，删除7777后，7778上有了数据。数据量太小的原因。
MongoDB有个0day，run操作可以直接执行shell命令。
文章为阿小信的个人笔记，转载请注明出处。
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