最近没事看来一下mongoDB,貌似很牛逼的样子.因为他不像通常的关系型数据库那么多的约束.而且语法看上去和js一样.
mongod --dbpath C:\zhuyang\zhuyang\mongodb\mongodb\db
---insert
db.person.insert({"name":"zhuyang","sex":"male")
db.person.insert({"name":"hello","sex":"world"})
person = {"name":"nametest","sex":"sextest"}
db.person.insert(person)
---find
db.person.find()
db.person.find({"name":"nametest"})
db.person.findOne()
--update
db.person.update({"name":"nametest"},{"sex":"testupdate"})
--remove
db.person.remove({"name":"nametest"})
db.person.remove({"sex":"testupdate"})
--------------some command
help ----see help doc
db.help(); --to see some command of db level
db.foo.help() ----help of collections
to see the funcion implementation can use function name directly. eg: db.foo.update
---------insert to doc -------------
--insert one record
db.foo.insert({"firstname":"zhu"}) --after this sentence , db will add another _id key(if doesnt defined) and save to doc.see below
db.foo.insert({"lastname":"yang"})
db.foo.insert({"firstname":"chen"})
> db.foo.find()
{ "_id" : ObjectId("52ce585fe2e2fd0a66329ee3"), "firstname" : "zhu" }
------------batch insert
use mongoimport
file<4MB, need a field name _id
-----------remove doc
db.foo.remove() ---remove all
db.foo.remove({"firstname":"chen"}) ---remove one record
------update doc ------
see below
db.user.insert(
{
"firstname":"zhu",
"lastname":"yang",
"friends":32,
"enemies":2
}
)
CHANGE TO
{
"username":"zhuyang",
"relation":
{
"friends":32,
"enemies":2
}
}
var zhuyang = db.user.findOne({"firstname":"zhu"})
zhuyang.relation={
"friends":zhuyang.friends,
"enemies":zhuyang.enemies
}
zhuyang.username="zhuyang"
delete zhuyang.firstname
delete zhuyang.lastname
delete zhuyang.friends
delete zhuyang.enemies
db.user.update({"firstname":"zhu"},zhuyang)
$set 修改器入门
db.user.insert(
{
"name":"joe",
"age":30,
"sex":"male",
"location":"shanghai"
}
)
//想要添加一个新的字段favorite book
//可用下面 2种办法
//1. 用update()
var joe = db.user.findOne({"name":"joe"})
joe.favoritebook="java";
db.user.update({"name":"joe"},joe);
//2. 使用修改器$set
db.user.update(
{
"name":"joe"
},
{
"$set":{
"favoritebook":"c++"
}
}
)
//也可以将favorite book改成一个数组
db.user.update(
{
"name":"joe"
},
{
"$set":{
"favoritebook":[
"c++","c##","perl"
]
}
}
)
//使用$unset 去移除
db.user.update(
{
"name":"joe"
},
{
"$unset":{
"favoritebook":1
}
}
)
//使用$set 修改内嵌文档
db.blog.posts.insert({
"title":"java test",
"content":"this is content",
"author":{
"name":"sb",
"mail":"[email protected]"
}
}
)
//修改作者名字为joe zhu
db.blog.posts.update(
{
"author.name":"sb"
},
{
"$set":
{
"author.name":"joe zhu"
}
}
)
//$inc 修改器用来增加已有键的值,或者在键不存在的时候创建
db.games.insert(
{
"game":"pinball",
"user":"joe"
}
)
//如果小球碰到了砖块,就会给玩家加分.分数随便给,这里把玩家的基数分数设做50.使用$inc 给玩家加50
db.games.update(
{
"game":"pinball",
"user":"joe"
},
{
"$inc":{
"score":50
}
}
)
//之前分数键是不存在的,所以用$inc创建了一个score键,并加量50
//如果小球落到指定位置,那么则加上1000分.
db.games.update(
{
"game":"pinball",
"user":"joe"
},
{
"$inc":{
"score":1000
}
}
)
//现在的分数变成了50+1000=1050了
//数组修改器
//如果指定的键已经存在,那么$push就会向已有的数组末尾加上一个元素,否则就会创建一个新的数组.
db.blog.posts.findOne({"author.mail":"[email protected]"});
{
"_id" : ObjectId("52cf9f70cae129f46ff6fa5d"),
"author" : {
"mail" : "[email protected]",
"name" : "joe zhu"
},
"content" : "this is content",
"title" : "java test"
}
//比如现在要添加一个数组comments键.并发布一条评论:
db.blog.posts.update(
{
"author.mail":"[email protected]"
},
{
"$push":{
comments:{
"name":"zhu",
"email":"[email protected]",
"content":"nice one"
}
}
}
);
> db.blog.posts.find()
{ "_id" : ObjectId("52cf9f70cae129f46ff6fa5d"), "author" : { "mail" : "[email protected]", "name" : "joe zhu" }, "comments" : [ { "name" : "zhu", "email" : "[email protected]",
"content" : "nice one" } ], "content" : "this is content", "title" : "java test" }
//如果还要添加一条评论
db.blog.posts.update(
{
"author.mail":"[email protected]"
},
{
"$push":{
"comments":{
"name":"yang",
"email":"[email protected]",
"content":"nice two"
}
}
}
)
db.blog.posts.findOne()
"_id" : ObjectId("52cf9f70cae129f46ff6fa5d"),
"author" : {
"mail" : "[email protected]",
"name" : "joe zhu"
},
"comments" : [
{
"name" : "zhu",
"email" : "[email protected]",
"content" : "nice one"
},
{
"name" : "yang",
"email" : "[email protected]",
"content" : "nice two"
}
],
"content" : "this is content",
"title" : "java test"
使用$addToSet添加新的数组元素
db.blog.posts.update(
{
"author.mail":"[email protected]"
},
{
"$addToSet":{
"comments":{
"name":"yang1",
"email":"[email protected]",
"content":"nice 3"
}
}
}
)
使用$addToSet和$each添加多个元素
db.user.update(
{
"_id":ObjectId("52cf9c6dcae129f46ff6fa5c")
},
{
"$addToSet":{
"favoritebook":{
"$each":[
"javascript",
"mongo in action"
]
}
}
}
)
//有几个从数组中删除元素的方法,如果把数组看作是一个栈或者队列.可以用$pop ,这个修改器可以从数组任何一端进行删除{$pop:{key:1}}从数组末端删除1个元素,{$pop:{key:-1}}从数组头删除1个元素
db.lists.insert(
{
"todo":[
"dishes",
"laundry",
"dry cleaning"
]
}
)
db.lists.update(
{
"_id":ObjectId("52cfac11cae129f46ff6fa5f")
},
{
"$pop":{
"todo":-1
}
}
)
//有时基于特定条件来进行删除,而不是依据位置,"$pull"可以做到
db.lists.update(
{
"_id":ObjectId("52cfad13cae129f46ff6fa60")
},
{
"$pull":{
"todo":"laundry"
}
}
)
//数组的定位修改器
//若是数数组有多个值,而我们只想对其中一部分做修改.通过位置或者定位操作符$
//数组都是从0开始的,我们可以通过下表进行访问元素
> db.blog.posts.findOne()
{
"_id" : ObjectId("52cfae34cae129f46ff6fa61"),
"author" : {
"name" : "sb",
"mail" : "[email protected]"
},
"comments" : [
{
"name" : "yang",
"email" : "[email protected]",
"content" : "nice two",
"vote" : 5
},
{
"name" : "yang1",
"email" : "[email protected]",
"content" : "nice 1",
"vote" : 6
}
],
"content" : "this is content",
"title" : "java test"
}
//如果想要增加其中一个元素的投票数
db.blog.posts.update(
{
"_id": ObjectId("52cfae34cae129f46ff6fa61")
},
{
"$inc":{//这里的$inc用来做增加,也就是说vote数量将会在原有基础上增加100
"comments.0.vote":100//comments.0第1个元素
}
}
)
//但是在很多情况下我们并不知道每一个元素的下标,这样就不能通过位置来操作, 而是用$来操作
db.blog.posts.update(
{
"comments.name": "yang" //若有多个匹配,则只会操作一个
},
{
"$set":{//直接设值
"comments.$.vote":300
}
}
)
//upsert 是一种特殊的更新方式,如果没文档符合更新条件,那么就会以这个条件和更新数据创建一个新的文档
db.user.update(
{
"edu":"gaozhong"//文档中没有edu==gaozhong
},
{
"$set":{
"age":100
}
},
true//true表名这是一个upsert方式的更新
)
db.user.find()
{ "_id" : ObjectId("52cfb32dedd18a0edc7db7b0"), "age" : 100, "edu" : "gaozhong" }