Hello This Is Your Individual Assignment Expectations
Hello This Is Your Individual Assignment Expectations Are That Yo
This assignment involves creating ERDs from an existing database, modifying the design, and generating SQL code to implement those changes. The database in question is the tutorial database from w3schools, accessible via their online editor. You need to diagram the database using a diagramming tool, applying proper ERD symbols for entities, relationships, weak, associative, and normal entities. The first ERD should be based on the original database, and the second should include modifications such as multiple stores, store details, inventory management, employee roles, and employment history. Additionally, you must generate SQL statements to alter the database to reflect these changes, including creating new tables, modifying existing tables, establishing constraints, and ensuring no key fields are null. Every SQL command must be accompanied by a screenshot showing the executed changes. The final submission should include the ERD of the original database, the ERD of the modified database, and all screenshots of SQL commands with their execution results. The assignment is worth 100 points and must be submitted through Canvas.
Paper For Above instruction
The task of designing an Entity-Relationship Diagram (ERD) for the w3schools tutorial database exemplifies practical database modeling skills essential for efficient database management and development. The process involves visualizing the database’s structure, understanding its entities, attributes, and relationships, and documenting these in a formal diagram. After creating the initial ERD, modifications are introduced to meet additional requirements for a multi-store retail environment, necessitating the creation of new tables, modification of existing ones, and detailed declaration of primary and foreign keys to maintain referential integrity. Furthermore, translating these modifications into SQL commands enables concrete alterations in the database, ensuring that the database structure aligns with the evolving business needs.
The original ERD serves as a foundational depiction of the database, showing key entities such as products, categories, and orders, along with their relationships. The creation of this ERD requires the use of diagramming tools such as Microsoft Visio, PowerPoint, or specialized ERD software, all of which provide the appropriate symbols for primary keys, foreign keys, weak entities, and associative entities. Symbol accuracy is crucial, as certain UML class diagram tools like Microsoft Project lack the specialized notation for ERDs.
Upon establishing the baseline ERD, the modifications reflect a more complex business scenario involving multiple stores. Each store has detailed attributes such as address, square footage, and contact information, along with an assigned store manager. The introduction of product inventories across multiple stores involves creating an Inventory table that tracks product quantities, available space, and store-specific inventories. Additionally, employees can have various roles (e.g., Sales Associate, Assistant Manager, Store Manager, Inventory Specialist), which call for a role attribute in the Employee entity. The employment history further complicates the model, requiring a new table that logs each employee’s contract period, role changes, and movements between stores, including start and end dates.
The SQL commands generated to reflect these design changes encompass creating new tables, such as the Stores table, Inventory table, EmploymentHistory table, and EmployeeRoles table. Modifications to existing tables include adding fields for store IDs, employee roles, and employment dates, with appropriate foreign key constraints to ensure referential integrity. Each SQL statement must be executed within the database environment, with screenshots capturing the 'after' state to demonstrate successful implementation. Constraints preventing null values in primary and foreign key fields are applied to maintain data consistency and integrity.
The final deliverable comprises the original ERD, the modified ERD, and a comprehensive set of SQL statements with execution screenshots. These components demonstrate proficiency in database modeling, normalization, constraint creation, and practical SQL scripting, all aligned with the business requirements for managing multiple store locations, inventories, and employee employment history effectively.
References
- Elmasri, R., & Navathe, S. B. (2015). Fundamentals of Database Systems (7th ed.). Pearson.