import java.sql.*; public class testMySql { // JDBC driver name and database URL static final String JDBC_DRIVER = "com.mysql.jdbc.Driver"; static final String DB_URL = "jdbc:mysql://localhost/cs4010"; // Database credentials static final String USER = "cs4010"; static final String PASS = "cs4010"; public static void main(String[] args) { Connection conn = null; Statement stmt = null; try { //STEP 2: Register JDBC driver Class.forName("com.mysql.jdbc.Driver"); //STEP 3: Open a connection System.out.println("Connecting to database..."); conn = DriverManager.getConnection(DB_URL,USER,PASS); //STEP 4: Execute a query System.out.println("Creating statement..."); stmt = conn.createStatement(); String sql; sql = "SELECT student_id, name, year, test FROM student"; ResultSet rs = stmt.executeQuery(sql); //STEP 5: Extract data from result set while (rs.next()) { //Retrieve by column name int id = rs.getInt("student_id"); String the_name = rs.getString("name"); String year = rs.getString("year"); int score = rs.getInt("test"); //Display values System.out.print("Student ID: " + id); System.out.print(", Name: " + the_name); System.out.print(", Year: " + year); System.out.println(", Entrance Test Score: " + score); } //STEP 6: Clean-up environment rs.close(); stmt.close(); conn.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) stmt.close(); } catch (SQLException se2) { }// nothing we can do try { if (conn!=null) conn.close(); } catch (SQLException se) { se.printStackTrace(); }//end finally try }//end try System.out.println("Goodbye!"); }//end main }//end FirstExample
MariaDB [cs4010]> select * from student; +------------+-----------+--------+------+ | student_id | name | year | test | +------------+-----------+--------+------+ | 1 | Joe Jones | Senior | 85 | | 3 | Sam Smith | Junior | 90 | | 4 | Bob Brown | Junior | 75 | +------------+-----------+--------+------+ 3 rows in set (0.00 sec) ~/javafiles/Servlets/src >java testMySql Connecting to database... Creating statement... Student ID: 1, Name: Joe Jones, Year: Senior, Entrance Test Score: 85 Student ID: 3, Name: Sam Smith, Year: Junior, Entrance Test Score: 90 Student ID: 4, Name: Bob Brown, Year: Junior, Entrance Test Score: 75 Goodbye!