Computer Science Homework Help

Data models are important in the categorization of data. A data model is a representation of the rules and data objects along with any associations between them. Data models help us see how the data relate, how they are stored, and how they will potentially be accessed. Being really careful in a data model for consistency for values, naming conventions of everything, and of course security of the data is always the goal.

Imagine if you ran a small eCommerce marketplace out of your house. Every day you got shipments to your store that went into your inventory. You had an online store that sold these products. The online store listed the estimated inventory of your products. However, each time you got a shipment, you entered products in a different way, or gave them different names, or sometimes forgot to enter them. If a customer went to purchase something from your online store and the inventory returned that the product was available but was not, the customer would pay and not receive the product. So, you can see how important accurate data models to produce an accurate visual representation of the data that follows all the conventions to provide consistency for that data.

Keeping that in mind, let’s explore how to represent business information as entities (or classes) and relationships in the data model. The data model facilitates the identification of data requirements for any business case and any type of database. A data model can also help communicate technical information to non-technical people so everyone in the company can develop a shared understanding of data and business processes. In the data model we will break down basic objects in groups which are entities. One entity will correlate to each table in our database. Then one instance of the entity will become a row.

Let’s consider specific examples of entities. Most businesses have employees and each employee would have attributes such as a name, address, their assigned location at work, their job title, pay rate or other attributes such as certifications or acquired skills. You would also have products within that business and the products would have specific values, types, descriptions, prices, sizes, and other requirements.

Whether you’re thinking about products, people, or other things about which you need to store information, you need to have a unique attribute (a.k.a., a primary key) to identify that ‘item’ as unique. So, for a book it would be the ISBN, other examples might include employee ID, product ID, Vehicle ID. In each of these last three cases, the unique identifier is assigned to the entity by the system.

To Prepare for this Assignment:

• Review the resources included in the Explore section.
• Review the “Sample Business Scenario” document.
• Review the “Sample UML Class Diagram
• 
  
• Requirements List
• 1. One customer can place an order for many products at a time.
  2. Many different customers may order any particular product.
  3. Workers at the warehouse keep track of orders while they fulfill and ship them.
  4. Customer service representatives should be able to review any customer’s orders, whether they are being fulfilled, in transit, or delivered. All orders include the date the order was placed by the customer, the date the order shipped, and the date the order was delivered.
  5. Five warehouses are available for shipping. The warehouses are located in Chicago, Denver, Los Angeles, Miami, and New York.
  6. Merchandise is always in stock. Zip code proximity determines warehouse association. Customer can only order from the closest warehouse to the receiving address.
  7. Orders ship by weight and size. Weight of any package cannot exceed 70 pounds. Size cannot exceed 3 meters square.
  8. Customers can cancel orders and return products up to four times a month.
  9. Different systems are used to process customer payments and manage inventory.
  10. Employee job types include warehouse worker, customer service representative, administrative staff, or management.
  11. Employees are assigned to a single warehouse. Only warehouse workers must work in the warehouse, all other employees have the option of working remotely from any location.

  Complete the following tasks:

  • Identify 5–8 entities in the list of requirements. Be sure the entities you identify allow you to store all the information specified in the requirements.
    • Remember, entities are things that you need to store information about in the database
    • If you need more than five to eight entities, you need to take a look at them and determine if two or more can be combined.
  • Create a list of attributes for each entity you identified. Attributes represent information you need to include in each entity to fulfill the system data requirements. Remember, attributes are information about entities, they are not themselves considered entities.
  • Include a written justification describing how the list of entities and attributes satisfy the data requirements of the given scenario.
  • To get you started, the Employee entity and suggested attributes is provided below. You may include additional attributes if you think it is necessary to fulfill the data requirements of the scenario. This will be one of the entities you identify from the requirements listing.