Employee Wage, Age, Status, Adler, Talario
Sheet1 Employee Wage Age Status Adler 4120045 Talario 3956543 Aanders 3098041 Aba
Analyze the provided data and develop a comprehensive relational database schema to manage employee records effectively. Your task includes creating diagrams, designing and populating the database, and generating reports and queries to demonstrate your understanding of database development principles.
Paper For Above instruction
Developing a relational database for employee management requires a systematic approach that encompasses designing the schema, creating and populating tables, establishing relationships, and generating meaningful reports. This process not only involves technical skills in SQL and data modeling but also an understanding of the specific data and its contextual application.
Understanding the Data and Requirements
The initial dataset appears to contain employee information, including identifiers, age, wages, and status indicators. The data structure seems to be somewhat unorganized in the initial form, which necessitates normalization and proper schema design. Additionally, there are references to a laboratory database involving patients, medication, and admissions, which seem to be part of a separate detailed example. The key emphasis here is on implementing a well-structured employee database.
Step 1: Creating Diagrams Using Visio
The first phase in database development involves creating entity-relationship diagrams (ERDs) using tools like Microsoft Visio. ER diagrams visualize entities such as Employees, Wages, and Status, along with their attributes and relationships. For the employee database, the main entities might be Employee, Wage, Age, and Status. Relationships could exist indicating that one Employee has one or more wages, or other relevant associations based on the data's semantics.
The ERD helps in understanding the data flow and establishing primary and foreign keys, ensuring the database adheres to normalization principles, particularly reaching Third Normal Form (3NF). Achieving 3NF ensures minimal redundancy and dependency issues, which is critical for data consistency and integrity.
Step 2: Designing the SQL Schema in 3NF
Once the ERD is established, the next step involves creating SQL scripts to develop the database schema. The script should include commands to create each table, define primary and foreign keys, and enforce referential integrity constraints. The tables might include:
- Employee
- Wage
- Status
Each table should contain a primary key, with foreign keys establishing the relationships. For example, the Employee table might have an Employee_ID as its primary key, while the Wage table may reference Employee_ID as a foreign key. Data types should be carefully selected to reflect the data stored; for instance, Employee_ID as NUMBER or INTEGER, Employee Name as VARCHAR2, and Age as NUMBER.
The script must include commands to drop existing tables before creation to prevent conflicts, especially during iterative development. Data insertion statements populate the tables with sample or actual data, which should be consistent with the schema's constraints.
Step 3: Populating the Database
Populating the database involves inserting realistic records into each table. For instance, employee records with their respective wages, age, and status should be added. Ensuring data integrity during insertion is essential; foreign key constraints must be respected, and data types must match the schema definitions. Data should be representative enough to facilitate meaningful reporting and querying.
Step 4: Generating Reports and Queries
The assignment specifies creating a report that includes data for all three patients, which extends to generating a comprehensive employee report in this context. Typical reports may include consolidated employee information, such as their wages, age, and status. Queries should retrieve data across related tables, for example:
- Listing all employees with their wages and statuses
- Filtering employees by age, wage range, or status
- Summarizing total wages or average age
Additionally, each student must add an individual query illustrating their particular area of interest or analysis. For example, a query identifying employees earning above a certain wage threshold or filtering employees based on status or age.
Step 5: Deliverables and Final Submission
The final deliverables include:
- The Visio ERD file (.vcd): The visual schema illustrating entities and relationships.
- The SQL Script file (.sql): A comprehensive script that creates, populates, and queries the database.
- The Spool output file (.lst): Output from executing the SQL script, including query results.
Development guidance recommends developing the script incrementally, testing each step, and documenting personal and program information within the script comments for clarity and reproducibility. The script should employ best practices, such as setting session parameters for readability, using cascading constraints when necessary, and verifying data integrity before proceeding.
Conclusion
The exercise emphasizes the importance of structured database design principles, proper normalization techniques, and effective SQL scripting in developing a relational database. Through this process, students solidify their understanding of entity relationships, constraints, data population, and report generation—all essential skills in database management and development.