sql预处理和session

PreparedStament sql预处理对象

PreparedStament pst =null;

String sql =" SELECT `userName`,`password` FROM `news_user` WHERE `userName` = ? AND `password` = ? " ;

Object[] pars ={user.getName(),user.getPwd()};

pst = connection.prepareStatement(sql);

for(int i =0;i

pst.setObject(i+1,parms[i])    //？占位符的初始下标为1，所以为了对应，i+1

}

int count = pst.excuteUpdate();  //执行失败返回-1  成功 有多少条返回多少条

Session

session创建：request.getsession()

             赋值 :session.setAttribute("","")

             获取: session.getAttribute("","")