Node.js + mongoose + mongodb 学习笔记

1. 安装 mongodb：

a）下载 最新版 Mongodb下载

tar xzf mongodb-osx-x86_64-2.2.0.tgz
sudo mv mongodb-osx-x86_64-1.4.0 /usr/local/mongodb
sudo chown -R root /usr/local/mongodb

数据库默认位置在： /data/db， 可以通过 －dbpath重设

b）启动 mongodb

打开一个 terminal：

/usr/local/mongodb/bin/mongod

将启动mongodb， 可以设置 PATH＝$PATH:/usr/local/mongodb/bin, 然后直接输入命令： mongod

打开另一个terminal：

/usr/local/mongodb/bin/mongo

将自动连接默认数据库test， 可以设置 PATH＝$PATH:/usr/local/mongodb/bin, 然后直接输入命令： mongo

c）简单操作 (obj is a json format object)

show collections 显示所有集合

db.collection_name.drop(); //delete a collection

db.collection_name.find(); // show all record in the collection

db.collection_name.save(obj);// create a record in the collection

db.collection_name.find()// search a record. '$gt' - >, '$gte' - >=, '$lt' - <, '$lte' - <=, '$ne' - !=, '$in' - 'is in array', '$nin' - ' ! in array'

db.collection_name.update() // update whole record, you have to give all fields by updating, all you will lost them, if u not give it in update

db.collection_name.update() by using '$set':obj // update partially, the values not shown here will not be changed

db.collection_name.update() by using '$pull' or '$push'//update partially for array field

db.collection_name.remove(); // remove all records in the collection

db.collection_name.remove(obj) // remove the obj in the collection

d) the collection namr which is by mongoose created is writed in small letter 

e.g.

/*
 * create model, 'user' plus 's' will be the collection name for MongoDB(database: 'smartlog', colloection: 'users')
 */
var User_model = mongoose.model('user', User_schema);

2 mongoose in Node.js

a) install mongoose model: npm install mongoose

b) include in server.js

var mongoose = require('mongoose');

c) connect to mongodb

mongoose.connect('mongodb://127.0.0.1/smartlog);   or

var db = mongoose.createConnection('localhost', 'smartlog');

d) create a dynamic schema:

var User_schema = new mongoose.Schema({userid: String});

e) create a model with predefined schema

var User_model = mongoose.model('user', User_schema);

f) using model to update

User_model.update({userId:userid},{'$set':{online: isOnline}}, function(err, count){});

g) using model to remove

User_model.remove({'userId':{'$in': userIds}},function(error, count){});

h)create a new record:

first: var newUser = new User_model({userId: XXXX});

second: newUser.save(function(error, user){});

i) search all records

User_model.find({},function(err, users){});

j) search a record

User_model.findOne({'userId':data.userId}, function(err, user){});