{
'index':
id: 'index'
title: 'Index Page'
content: 'this is the index page'
tags: []
position: 1
category: 1
'jquery':
id: 'jquery'
title: 'jQuery'
content: 'this is about jQuery'
tags: ['jquery']
position: 2
category: 1
'history':
id: 'history'
title: 'History.js'
content: 'this is about History.js'
tags: ['jquery','html5','history']
position: 3
category: 1
}
collection.find tags: $in: ['jquery']