JDBCExample

//STEP 1. Import required packages
import java.sql.*;

public class JDBCExample {

    // JDBC driver name and database URL
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://localhost:3306/students";

    //  Database credentials
    static final String USER = "root";
    static final String PASS = "asdf";

    public static void main(String[] args) {
        Connection con = null;
        Statement stmt = null;

        try {
            //STEP 2: Register JDBC driver
            Class.forName(JDBC_DRIVER);

            //STEP 3: Open a connection
            System.out.println("Connecting to a selected database ... ");
            con = DriverManager.getConnection(DB_URL, USER, PASS);
            System.out.println("Connected database successfully.");

            //STEP 4: Execute a query
            System.out.println("Creating statement.");
            stmt = con.createStatement();

            String sql = "SELECT id, first_name, last_name, age FROM registration";
            ResultSet rs = stmt.executeQuery(sql);

            //STEP 5: Extract data from result set
            while(rs.next()){
                //Retrieve by column name
                int id  = rs.getInt("id");
                String firstName = rs.getString("first_name");
                String lastName = rs.getString("last_name");
                int age = rs.getInt("age");

                //Display values
                System.out.print("ID: " + id);
                System.out.print(", Age: " + age);
                System.out.print(", First: " + firstName);
                System.out.println(", Last: " + lastName);
            }
            rs.close();
        }catch(SQLException se){

            //Handle errors for JDBC
            se.printStackTrace();

        }catch(Exception e){

            //Handle errors for Class.forName
            e.printStackTrace();

        }finally{
            //finally block used to close resources
            try{
                if(stmt!=null)
                    con.close();
            }catch(SQLException se){  /* do noting if still some exception */ }

            try{
                if(con!=null)
                    con.close();
            }catch(SQLException se){
                se.printStackTrace();
            }//end finally try
        } //end try

        System.out.println("Goodbye!");

    }//end main

}//end JDBCExample