Mongodb and MongoMapper Supporting tagline
Install mongodb
brew install mongodb
mongodb homepage http://www.mongodb.org/display/DOCS/Home
some usual mongo commands :
show dbs
show collections
show users
show profile
use <db name>
db.help() help on DB methods
db.foo.help() help on collection methods
db.foo.find() list objects in collection foo
db.foo.find( { a : 1 } ) list objects in foo where a == 1
CURD
create
db.createCollection(“user”);
insert
db.user.insert({uid:1,username:”yiwinking”,age:1});
find
db.user.find();
db.user.find({uid:1});
find methods :limit ，sort ，findOne，distinct
update
db.user.update({uid:1},{$set:{age:26}})
update method :$unset、$push 、$pushAll 、$pop 、$pull 、$pullAll
some skills
find out using db :db
change db :use "db"
find out mongodb commands: help
find out db methods : db.help()
Mongo mapper
Document:http://mongomapper.com/
install gem install mongo_mapper
Querying
Finders methods: (Actually,the methods like rails)
Model.all => find all
Model.find(id) => find though id
Model.first' , Model.last => first and last one
- Model.paginate({
-
order => :created_at.asc,
-
per_page => 25,
-
page => 3,
})
per_page means per in every page
page means in which page.
models = Model.where(:first_name => "winking", :last_name => "Yi")
Model.count => number of model’s obj
Model.sort(:first_name) => sort by first_name
Model.sort(:first_name).limit(100) find objs with 100 limit
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