Exemplo de update e delete usando o JDBC 1

    Connection connection = null;
    try {
        // Load the JDBC driver
        String driverName = "oracle.jdbc.driver.OracleDriver";
        Class.forName(driverName);
    
        // Create a connection to the database
        String serverName = "127.0.0.1";
        String portNumber = "1521";
        String sid = "mydatabase";
        String url = "jdbc:oracle:thin:@" + serverName + ":" + portNumber + ":" + sid;
        String username = "username";
        String password = "password";
        connection = DriverManager.getConnection(url, username, password);
    } catch (ClassNotFoundException e) {
        // Could not find the database driver
    } catch (SQLException e) {
        // Could not connect to the database
    }

    Connection connection = null;
    try {
        // Load the JDBC driver
        String driverName = "org.gjt.mm.mysql.Driver"; // MySQL MM JDBC driver
        Class.forName(driverName);
    
        // Create a connection to the database
        String serverName = "localhost";
        String mydatabase = "mydatabase";
        String url = "jdbc:mysql://" + serverName +  "/" + mydatabase; // a JDBC url
        String username = "username";
        String password = "password";
        connection = DriverManager.getConnection(url, username, password);
    } catch (ClassNotFoundException e) {
        // Could not find the database driver
    } catch (SQLException e) {
        // Could not connect to the database
    }

    try {
        // Load the JDBC driver
        String driverName = "org.gjt.mm.mysql.Driver";
        Class.forName(driverName);
    } catch (ClassNotFoundException e) {
        // Could not find the driver
    }

    try {
        Statement stmt = connection.createStatement();
    
        // Use TRUNCATE
        String sql = "TRUNCATE my_table";
    
        // Use DELETE
        sql = "DELETE FROM my_table";
    
        // Execute deletion
        stmt.executeUpdate(sql);
    } catch (SQLException e) {
    }

   try {
        // Create a statement
        Statement stmt = connection.createStatement();
    
        // Prepare a statement to insert a record
        String sql = "DELETE FROM my_table WHERE col_string='a string'";
    
        // Execute the delete statement
        int deleteCount = stmt.executeUpdate(sql);
        // deleteCount contains the number of deleted rows
    
        // Use a prepared statement to delete
    
        // Prepare a statement to delete a record
        sql = "DELETE FROM my_table WHERE col_string=?";
        PreparedStatement pstmt = connection.prepareStatement(sql);
        // Set the value
        pstmt.setString(1, "a string");
        deleteCount = pstmt.executeUpdate();
        System.err.println(e.getMessage());

    try {
        Statement stmt = connection.createStatement();
    
        // Prepare a statement to update a record
        String sql = "UPDATE my_table SET col_string='a new string' WHERE col_string = 'a string'";
    
        // Execute the insert statement
        int updateCount = stmt.executeUpdate(sql);
        // updateCount contains the number of updated rows
    } catch (SQLException e) {
    }

   try {
        Statement stmt = connection.createStatement();
    
        // Prepare a statement to insert a record
        String sql = "INSERT INTO my_table (col_string) VALUES('a string')";
    
        // Execute the insert statement
        stmt.executeUpdate(sql);
    } catch (SQLException e) {
    }