How to model Student/Classes with DynamoDB (NoSQL)

Question

I\'m trying to get my way with DynamoDB and NoSQL.

What is the best (right?) approach for modeling a student table and class tables with respect to the fact that I need

Answer 1

To join two Amazon DynamoDB tables

The following example maps two Hive tables to data stored in Amazon DynamoDB. It then calls a join across those two tables. The join is computed on the cluster and returned. The join does not take place in Amazon DynamoDB. This example returns a list of customers and their purchases for customers that have placed more than two orders.

CREATE EXTERNAL TABLE hive_purchases(customerId bigint, total_cost double, items_purchased array) 
STORED BY 'org.apache.hadoop.hive.dynamodb.DynamoDBStorageHandler'
TBLPROPERTIES ("dynamodb.table.name" = "Purchases",
"dynamodb.column.mapping" = "customerId:CustomerId,total_cost:Cost,items_purchased:Items");

CREATE EXTERNAL TABLE hive_customers(customerId bigint, customerName string, customerAddress array) 
STORED BY 'org.apache.hadoop.hive.dynamodb.DynamoDBStorageHandler' TBLPROPERTIES ("dynamodb.table.name" = "Customers",
"dynamodb.column.mapping" = "customerId:CustomerId,customerName:Name,customerAddress:Address");

Select c.customerId, c.customerName, count(*) as count from hive_customers c 
JOIN hive_purchases p ON c.customerId=p.customerId 
GROUP BY c.customerId, c.customerName HAVING count > 2;