DB Migration: Update Post Types Counts

gistfile1.txt

var businesses = db.getCollection('businesses').find({});
businesses.map(function(business) {
    var posts = db.getCollection('posts').find({_business: business._id});
    var postTypesCount = {
      idea: 0, offer: 0, news: 0, problem: 0, question: 0, review: 0    
    };
    posts.forEach(function(post) {
        postTypesCount[post.type]++;
    })
    return db.getCollection('businesses').update({_id: business._id}, {$set: {
      post_types_count: postTypesCount  
    }})
})