feat(jdbc-sqlite): demonstrate secure querying with Prepared Statements

What
- Introduced `Prepared Statements` example under Section28JDBCusingSQLite.
- Showcases how to execute parameterized SQL queries using `PreparedStatement`.
- Demonstrates binding input values dynamically (e.g., deptno).
- Prints student records matching the query or notifies when no data is found.

Why
- Prevents SQL injection by avoiding direct string concatenation in queries.
- Provides reusability: same SQL template can be executed with different parameters.
- Improves performance as the query is compiled once and reused by the database engine.
- Enhances clarity and safety compared to plain `Statement`.

How
- Loaded SQLite JDBC driver (`Class.forName("org.sqlite.JDBC")`).
- Established connection to `univ.db` database via `DriverManager`.
- Prepared a query template:
  `SELECT * FROM students WHERE deptno = ?`.
- Bound parameter using `pstm.setInt(1, dno)`.
- Executed query with `executeQuery()` and iterated through `ResultSet`.
- Printed student details (roll, name, city, deptno) in structured format.
- Closed JDBC resources (`PreparedStatement`, `Connection`) after execution.

Key Notes
- `?` placeholders allow flexible runtime parameter substitution.
- Use `setInt`, `setString`, etc. depending on parameter type.
- Safer than concatenating user input into raw SQL strings.
- `PreparedStatement` improves both performance and security.

Real-life Applications
- Login systems: verify username/password securely.
- E-commerce: filter products by category, price, or stock availability.
- Banking: fetch transactions by account number or date range.
- HR systems: query employees by department, role, or salary band.

Future Improvements
- Add multiple parameters to demonstrate complex queries (e.g., deptno + city).
- Integrate try-with-resources to simplify resource management.
- Extend to INSERT, UPDATE, DELETE queries using `PreparedStatement`.
- Implement input validation for better user interaction.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan