Exercises 1 And 2: Using Your Knowledge Of Premiere Products
Exercises 1 And 2 1using Your Knowledge Of Premiere Products Deter
Using your knowledge of Premiere Products, determine the functional dependencies that exist in the provided tables. After identifying these dependencies, convert the tables into an equivalent collection that adheres to third normal form (3NF). The tables under consideration are as follows:
- Part (PartNum, Description, OnHand, Class, Warehouse, Price)
- Order (OrderNum, OrderDate, CustomerNum, CustomerName, RepNum, LastName, FirstName, NumOrdered, QuotedPrice)
- Invoice (InvoiceNum, CustomerNum, LastName, FirstName, Street, City, State, Zip, Date, PartNum, Description, Price, NumShipped)
- Orders (OrderNum, OrderDate, PartNum, Description, NumOrdered, QuotedPrice)
- Rep (RepNum, LastName, FirstName, Street, City, State, Zip, Commission, Rate)
- Customer (CustomerNum, CustomerName, Street, City, State, Zip, Balance, CreditLimit, RepNum)
- OrderLine (OrderNum, PartNum, NumOrdered, QuotedPrice)
Additionally, analyze the functional dependencies within the Orders table: OrderNum determines OrderDate; PartNum determines Description; the composite key (OrderNum, PartNum) determines NumOrdered, QuotedPrice, and OrderDate. Recognize how these dependencies influence the normalization process and the design of the database schema.
Sample Paper For Above instruction
Proper database normalization is essential for designing efficient, consistent, and reliable relational databases. In the context of Premiere Products, understanding and applying the principles of functional dependencies and third normal form (3NF) ensures data integrity and minimizes redundancy across various tables involved in inventory management, sales, invoicing, and customer relations.
The initial step in the normalization process is to identify the functional dependencies within each table. For instance, in the Parts table, PartNum uniquely determines Description, OnHand, Class, Warehouse, and Price. This is a straightforward dependency, as each part number corresponds to a specific part with distinct attributes. Recognizing these dependencies guides us toward decomposing tables into smaller, well-structured relations that eliminate redundancy.
Likewise, the Order table initially lists multiple attributes, including OrderNum, OrderDate, Customer information, and details pertaining to the salesperson. The dependency OrderNum → OrderDate indicates that each order has a single date, which should be stored in a separate Orders table containing only one record per order. The detailed customer and salesperson information, such as CustomerNum, CustomerName, LastName, FirstName, and customer address, are functionally dependent on CustomerNum and should be stored in dedicated Customer and Rep tables, respectively.
In the invoicing context, the Invoice table includes multiple pieces of customer and product information. The identification of each invoice by InvoiceNum, with associated customer details, underscores the importance of separating customer attributes into a Customer table. The parts listed on each invoice, along with their description, price, and quantity shipped, indicate a many-to-many relationship between invoices and parts, mediated by an InvoiceLine or similar associative table.
To convert these tables into third normal form, we must eliminate transitive dependencies and ensure that each non-key attribute depends solely on the primary key. For example, in the Customer table, CustomerName and address attributes depend on CustomerNum; in the Rep table, employee details depend on RepNum. Similarly, the Orders table should contain only order identifiers and dates, with customer and employee details stored separately.
This normalization facilitates database consistency, easier maintenance, and query efficiency. It also simplifies data updates, as each piece of information is stored in only one place. Furthermore, it enhances data integrity enforceable through primary and foreign key constraints, ensuring that relationships between entities such as Customers, Orders, and Parts remain consistent.
In conclusion, by systematically analyzing functional dependencies and applying the rules for third normal form, the database schema for Premiere Products can be optimized. Such a schema supports robust data management and provides a strong foundation for expanding functionalities like invoicing and order processing without sacrificing integrity or performance.