I Need Help With This Homework ASAP I Have Done Research

I Need Help With This Homework Asap I Have Done Research And Just C

The task involves modifying an existing database schema that captures information about states, capitals, and related attributes. The specific adjustment to be made is the addition of an attribute called "CountyName" to record the county or counties containing each state capital.

First, an analysis of where to place such an attribute is required. Given the scope and design of the current database, "CountyName" pertains to the geographic subdivision (county) rather than an entity about the state or the capital itself. This makes it most appropriate to associate it directly with the entity representing a capital, since each capital can reside in one or more counties, and the relation detailed in the data already links each capital to its state via the "State Abbrev" foreign key.

Therefore, the best approach is to add the "CountyName" attribute into the existing "Capital" relation. Doing so aligns with normalization principles, since each capital's county or counties are specific to that record, and it avoids redundancy or unnecessary data duplication.

In terms of database design, if a capital can span multiple counties (as in the case of Austin and Lansing), this suggests a need for a separate associative or junction entity: a "CapitalCounty" table. However, if each capital is associated with a single primary county, then adding a "CountyName" attribute directly to the "Capital" relation suffices. The assignment states the counties for each capital, specifying multiple counties for some (e.g., Travis and Williamson Counties for Austin, TX), which indicates a need for a many-to-many relationship mapping between capitals and counties.

Consequently, the most appropriate solution involves creating a new entity called "County," which contains "CountyName" and references the associated "Capital" via a foreign key. This approach allows for multiple counties per capital and adheres to relational database normalization. It also maintains the flexibility to model multiple counties for a single capital comprehensively.

Entity-Relationship Diagram Description

The ER diagram will include the following entities:

  • State: with attributes StateAbbrev (PK), StateName, EnteredUnionOrder, StateBird, StatePopulation.
  • Capital: with attributes CapitalName, StateAbbrev (FK), YearDesignated, CapitalPopulation.
  • County: with attributes CountyID (PK), CountyName, and a foreign key to the Capital entity (e.g., CapitalName or a dedicated CapitalID).

The relationships are as follows:

  • The State entity is linked to Capital via StateAbbrev (one-to-many), since each state has one capital in this simplified model.
  • The Capital entity is linked to County via a one-to-many relationship, allowing multiple counties to be associated with a single capital.

This structure effectively captures the requirement that each capital can be located in one or more counties, and each county contains the capital. It maintains normalization and data integrity, facilitating flexible querying and reporting about states, capitals, and their counties.

Conclusion

In summary, the most appropriate solution is to create a new "County" entity containing "CountyName" and linking it to the existing "Capital" entity. This approach accommodates multiple counties per capital, aligns with relational database design principles, and simplifies data management. The ER diagram reflects these entities and their relationships, providing a clear visual model for implementing the revised database schema.

References

  • Elmasri, R., & Navathe, S. B. (2015). Fundamentals of Database Systems (7th ed.). Addison-Wesley.
  • Communications of the ACM, 13(6), 377-387.
  • Relational Database Design and Implementation. Morgan Kaufmann.
  • Database System Concepts (6th ed.). McGraw-Hill Education.
  • Journal of Data Management, 21(3), 45-63.
  • An Introduction to Database Systems. Pearson Education.
  • Principles of Transaction Processing. Morgan Kaufmann.
  • Geography & Environment, 1(3), 246–265.
  • International Journal of Geographic Information Science, 32(4), 770-790.
  • Turkish Journal of Computer and Mathematics Education (TURCOMAT), 11(5), 2093-2102.

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