rbiodies / alfa

:bank: SQL expressions for queries; combination queues into one ordered queue, eliminating duplicate elements; implementation symmetric difference

Alfa

Task number 4.

The banking system contains the main account table, which stores the accounts of all bank customers:

CREATE TABLE account (

id CHAR NOT NULL, -- account ID

client_id CHAR NOT NULL, -- identifier of the client, account holder

created DATE, -- account opening date

closed DATE, -- account closing date

amount BIGINT, -- account balance

PRIMARY KEY(id)

)

It is necessary to write SQL expressions for queries that return:

• list of open client accounts client_id=<client number> today
• list of clients who have closed all their accounts
• list of the most "valuable" clients for the bank, explaining how you define the "value" of a client

Task number 5.

Given two ordered queues that may contain the same elements. Combine (Java) these queues into one ordered queue, eliminating duplicate elements.

Task number 6.

Implement (Java) symmetric difference of two collections using Collection methods (addAll(), removeAll(), retainAll()).