//执行删除操作
  public int delete(member m) {
    int ret = 0;
    try{
    String sql = "delect from tb_member where ID=" + m.getID();
    ret=conn.executeUpdate(sql);        //这句没执行      没调用executeUpdate()    ？？？
System.out.println("ret="+ret);
    } catch(Exception e) {
        ret=0;
    }

    conn.close();
    return ret;
  }

  public int executeUpdate(String sql) {
    int result = 0;
    try {
      conn = getConnection();
      stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                  ResultSet.CONCUR_READ_ONLY);
      result = stmt.executeUpdate(sql);
    }
    catch (SQLException ex) {
      result = 0;
    }
    try {
      stmt.close();
    }
    catch (SQLException ex1) {
    }
    return result;
  }