dynamo

var commentSchema = new Schema({
  postId: {
    type: String,
    hashKey: true
  },
  id: {
    type: String,
    rangeKey: true,
    default: shortId.generate
  },
  timestamp: Date
  commenterId: {
    type: String,
    required: true,
    index: {
      global: true,
      rangeKey: 'timestamp',
    }
  },
  text: String,
  likes: Number
});

var Comment = dynamoose.model('Comment', commentSchema);

// Get a single comment using the table key
Comment.get(
  {postId: postId, id: commentId}, // this is the table key (hash and range)
  function (err, comment) {...}
);

// Get all comments for a post 
Comment
  .query('postId').eq(postId) // only table hash key is used 
  .exec(function (err, allCommentsForPost) {...});

// Get all comments for a commenter
Comment
  .query('commenterId').eq(commenterId) // hash key for index
  .exec(function (err, allCommentsForCommenter) {...});

// Get all comments for a commenter within last 10 days (uses range key)
Comment
  .query('commenterId').eq(commenterId)
  .where('timestamp').ge(Date.now() - 8.64e+8) // use .where for range keys
  .exec(function (err, commentsForCommenterWithin10Days) {...});

// Get all comments for a commenter with likes (uses filters - slower than range)
Comment
  .query('commenterId').eq(commenterId)
  .filter('likes').gt(0) // use filter when not a range key
  .exec(function (err, commentsForCommenterWithLikes) {...});