UPDATE: Streamlined Code Structure!

- Changed method access modifiers to increase encapsulation and security.
- Introduced `readonly` for the database connection string to prevent
  unintentional modifications.
- Parameterized SQL queries and commands to prevent SQL injection
  vulnerabilities.
- Refined method parameter lists for better readability and maintainability.
- Improved SQL query structure and syntax for better database interactions.

-----------------------------------------------------------------------------

	modified:   StudentManagementSystem/Program.cs

Author: softcodenet