```java public void delStudent(){ //获取连接 Connection conn = DbUtil.getConnection(); //sql, 每行加空格 String sql = "delete from student where id=?"; //预编译SQL，减少sql执行 PreparedStatement ptmt = conn.prepareStatement(sql); //传参 ptmt.setInt(1, id); //执行 ptmt.execute(); DbUtil.close(ptmt,conn); } ```