Enterprise Application Programming

Description: A backend for a Twitter-like application. The functionality of the application should have the following: 1. At least 2 roles :Producer and Subscriber 2. The Producers role is the same as the Subscriber, but has some extra capabilities: The producer can produce messages, which the Subscribers get 3. User may have both roles at the same time; 4. Users having the Subscriber role, which means they can subscribe to as many Producers as they want to; 5. All messages stored in the database, can be easily searched based on the following criteria: - User (Producer) ID – means who wrote it; - Message content Tasks: 1. Acquiring design patterns, build a data model for the application described in the above Description section together with API Contracts 2. The following are required: • ERD diagram (if you use RDBMS) as a picture of JPEG/PNG format; • Script to create the data model in the DB (SQL for RDBMS, CQL for Cassandra, etc.), which should be runnable, and creates an expected data structure; • Script to populate the database with few records (2-3 users, 5-7 messages); • A minimum of the following queries: i. Get list of users; ii. Get list of content producers; iii. Get list of content subscribers (full); iv. Get list of content subscribers, subscribed on specific producer; v. Get all messages; vi. Get all messages created by specific producer; vii. Get all messages for given subscriber (it may include messages from multiple producers).