mongo DB的一般操作

最近接触了一些mongoDB 。将一些指令操作记录下来，便于查询和使用

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[root@logs ~]# mongo -u loguser -p log123456 --authenticationDatabase admin
MongoDB shell version: 2.4.10
connecting to: test
> show users
> post = {"title":"My Blog Post","Content":"Here is my blog Post.","Date":new Date()}
{
        "title" : "My Blog Post",
        "Content" : "Here is my blog Post.",
        "Date" : ISODate("2015-02-11T03:12:03.061Z")
}

插入
--插入文档对象
> db.blog.insert(post)
> post = {"title":"Licz Blog Post","Content":"Here is my blog Post.","Date":new Date()}
{
        "title" : "Licz Blog Post",
        "Content" : "Here is my blog Post.",
        "Date" : ISODate("2015-02-11T03:17:07.219Z")
}
> db.blog.insert(post)

读取
--读取集合里一个文档
> db.blog.findOne()
{
        "_id" : ObjectId("54dac88dc956bbcbefa8151c"),
        "title" : "My Blog Post",
        "Content" : "Here is my blog Post.",
        "Date" : ISODate("2015-02-11T03:12:03.061Z")
}

--读取限定文档数
> db.blog.find().limit(100);
> db.blog.find().limit(100);
{ "_id" : ObjectId("54dac88dc956bbcbefa8151c"), "title" : "My Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:12:03.061Z") }
{ "_id" : ObjectId("54dac9b8c956bbcbefa8151d"), "title" : "Licz Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:17:07.219Z") }

--读取所有文档数
> db.blog.find()
{ "_id" : ObjectId("54dac88dc956bbcbefa8151c"), "title" : "My Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:12:03.061Z") }
> db.blog.find().limit(100);
{ "_id" : ObjectId("54dac88dc956bbcbefa8151c"), "title" : "My Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:12:03.061Z") }
{ "_id" : ObjectId("54dac9b8c956bbcbefa8151d"), "title" : "Licz Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:17:07.219Z") }

更新

--修改变量post,增加comments键
> post
{ "title" : "You Blog Post", "Date" : ISODate("2015-02-11T03:18:10.509Z") }
> post.comments=[]
[ ]
> db.blog.update({title:"You Blog Post"},post)
> db.blog.find()
{ "_id" : ObjectId("54dac88dc956bbcbefa8151c"), "title" : "My Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:12:03.061Z") }
{ "_id" : ObjectId("54dac9b8c956bbcbefa8151d"), "title" : "Licz Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:17:07.219Z") }
{ "_id" : ObjectId("54dac9f8c956bbcbefa8151e"), "title" : "You Blog Post", "Date" : ISODate("2015-02-11T03:18:10.509Z"), "comments" : [ ] }

删除

--删除title限定条件的文档
> db.blog.remove({title:"You Blog Post"})
> db.blog.find()
{ "_id" : ObjectId("54dac88dc956bbcbefa8151c"), "title" : "My Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:12:03.061Z") }
{ "_id" : ObjectId("54dac9b8c956bbcbefa8151d"), "title" : "Licz Blog Post", "Content" : "Here is my blog Post.", "Date" : ISODate("2015-02-11T03:17:07.219Z") }
> 

MongoDB使用技巧

--help帮助命令
> help
        db.help()                    help on db methods
        db.mycoll.help()             help on collection methods
        sh.help()                    sharding helpers
        rs.help()                    replica set helpers
        help admin                   administrative help
        help connect                 connecting to a db help
        help keys                    key shortcuts
        help misc                    misc things to know
        help mr                      mapreduce


        show dbs                     show database names
        show collections             show collections in current database
        show users                   show users in current database
        show profile                 show most recent system.profile entries with time >= 1ms
        show logs                    show the accessible logger names
        show log [name]              prints out the last segment of log in memory, 'global' is default
        use <db_name>                set current database
        db.foo.find()                list objects in collection foo
        db.foo.find( { a : 1 } )     list objects in foo where a == 1
        it                           result of the last line evaluated; use to further iterate
        DBQuery.shellBatchSize = x   set default number of items to display on shell
        exit                         quit the mongo shell

--特殊集合名处理
如果集合名恰好是和数据库类的一个属性名相同，可以使用db.getCollection进行访问

> db.version
function (){
    return this.serverBuildInfo().version;
}
> db.getCollection("version")
test.version