import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class SimpleJDBC {
	public static void main(String[] args) {
		//1. 드라이버 로드
		try {
			Class.forName("oracle.jdbc.driver.OracleDriver");
			System.out.println("드라이버로드 성공");
		} catch (ClassNotFoundException e) {
			System.out.println("드라이버클래스를 찾을 수 없습니다.");
		}
		//2. 커넥션 생성
		Connection con = null;
		try {
			String URL = "jdbc:oracle:thin:@localhost:1521/xe";
			String ID = "hr";
			String PW = "hr";
			con = DriverManager.getConnection(URL, ID, PW);
			System.out.println(con);
		//3. SQL 구문 작성
			String sql = "select first_name, salary from employees where employee_id=103";
		
		//4. Statement 객체 생성
			PreparedStatement stmt = con.prepareStatement(sql);
			
		//5. 쿼리문 실행
			ResultSet rs = stmt.executeQuery();
			
		//6. 결과집합 소비
			if(rs.next()) {
				String name = rs.getString("first_name");
				int salary = rs.getInt("salary");
				System.out.println(name + ", " + salary);
			}else {
				System.out.println("조회한 데이터가 없습니다.");
			}
			
		}catch(SQLException e) {
			System.out.println(e.getMessage());
		}finally {
		//7. 커넥션 닫기
			if(con!=null) {
				try { con.close(); } catch(Exception e) {}
			}
		}
	}//end main
}//end class