Imagine you are designing a database for a system for an online retail store that needs to manage customer orders and product inventory through a web application. The system should allow users to view products, add them to a shopping cart, and place orders.

$($b$)1$dentify the key entities in the database, specifying the entity name, attributes, data types, relationships, and cardinality constraints.

$[10$ marks$]$

$($c$)$ The store requires reports on the orders made in the store. Create SQL statements that can produce each of the following reports:

$1.$ A list of all products and the quantity held in stock.

$[1$ mark$\}$

$2.$ A list of all products and the quantity sold in each month.

$[3$ marks$]$

$3.$The top $10$ spending customers of all time.

$[4$ marks$)$

$($d$)$ The retail store merges with another store who have their own database. Describe the challenges that might be encountered in merging these databases and explain how these challenges might be overcome

$[6$ marks$)$