修改操作代码实现

• 修改操作
  */
  public void demo2(){
  Connection conn = null;
  PreparedStatement pstmt = null;
  try{
  // 获得连接:
  conn = JDBCUtils.getConnection();
  // 编写SQL语句:
  String sql = "update user set username = ?,password =?,nickname=?,age = ? where id = ?";
  // 预编译SQL:
  pstmt = conn.prepareStatement(sql);
  // 设置参数:
  pstmt.setString(1, "abc");
  pstmt.setString(2, "1234");
  pstmt.setString(3, "旺旺");
  pstmt.setInt(4, 23);
  pstmt.setInt(5, 6);
  // 执行SQL：
  int num = pstmt.executeUpdate();
  if(num > 0){
  System.out.println("修改成功！");
  }
  }catch(Exception e){
  e.printStackTrace();
  }finally{
  JDBCUtils.release(pstmt, conn);
  }
  }`