我正在使用
mongodb的node-
mongodb-native驱动程序来编写一个网站.
我有一个关于如何打开mongodb连接一次的问题,然后在user.js中的集合名称用户和comment.js中的集合名称帖子中使用它
我想在db.js中打开db连接,然后为用户和帖子集合插入/保存数据
目前代码,我的db.js
var Db = require('mongodb').Db,Connection = require('mongodb').Connection,Server = require('mongodb').Server;
module.exports = new Db(
'blog',new Server('localhost',Connection.DEFAULT_PORT,{auto_reconnect: true})
);
我在user.js中使用了db.js,如下所示
var mongodb = require('./db');
function User(user){
this.name = user.name;
this.password = user.password;
this.email = user.email;
};
module.exports = User;
User.prototype.save = function(callback) {//save user information
//document to save in db
var user = {
name: this.name,password: this.password,email: this.email
};
mongodb.close();
//open mongodb database
mongodb.open(function(err,db){
if(err){
return callback(err);
}
//read users collection
db.collection('users',function(err,collection){
if(err){
mongodb.close();
return callback(err);
}
//insert data into users collections
collection.insert(user,{safe: true},user){
mongodb.close();
callback(err,user);//success return inserted user information
});
});
});
};
和comment.js
var mongodb = require('./db');
function Comment(name,day,title,comment) {
this.name = name;
this.day = day;
this.title = title;
this.comment = comment;
}
module.exports = Comment;
Comment.prototype.save = function(callback) {
var name = this.name,day = this.day,title = this.title,comment = this.comment;
mongodb.open(function (err,db) {
if (err) {
return callback(err);
}
db.collection('posts',function (err,collection) {
if (err) {
mongodb.close();
return callback(err);
}
//depend on name time and title add comment
collection.findAndModify({"name":name,"time.day":day,"title":title},[ ['time',-1] ],{$push:{"comments":comment}},{new: true},comment) {
mongodb.close();
callback(null);
});
});
});
};
解决方法
您可以连接一次,然后根据需要重复使用多次：
var mongodb = require('mongodb');
var events = require('events');
var event = new events.EventEmitter();
var access = new mongodb.Server(host,port,{ });
var client = null;
new mongodb.Db('YOUR DATABASE',access,{ safe: true,auto_reconnect: true }).open(function (err,c) {
if (!err) {
client = c;
console.log('database connected');
event.emit('connect');
} else {
console.log('database connection error',err);
event.emit('error');
}
});
exports.get = function(fn) {
if(client) {
fn(client);
} else {
event.on('connect',function() {
fn(client);
});
}
};
然后重复使用它：
var db = require('./db');
var items;
db.get(function(client) {
items = new mongodb.Collection(client,'collection');
});
// then anywhere in your code
db.get(function() {
// items.find({ ...
});
