at _index__jsp._jspService(/index.jsp:7),index.jsp第七行错误,如果没有估计错的话, 数据库连接conn没有实例化
uname没有取到值,为null,运行uname.length()就出错了
select username from test where username="+uname+"and pwd="+pwd+""; ^^^^^^^^^^^^^^^^^^^^^^^^^SQL语句问题,好好看看!!
if(uname==null) {//null 处理}
请问wandou999与各位,下面这条语句应该什么样去改正才能连到数据库的值,做到密码与用户判断?上面的程序我运行以后,返回的结果是的总是密码错误,显然是数据库没有连接到??谢谢 select pwd from test where username="+uname+"and pwd="+pwd+"";
<%@page contentType="text/html;charset=GBK"%>
<%@page import="java.sql.*"%>
<jsp:useBean id="Conn" scope="page" class="sqlconn.Conn"/>
<%
String uname=request.getParameter("username");
String pwd=request.getParameter("passwd");
if(uname.length()!=0)
{
if(pwd.length()==0)
{
out.println ("<script language=javascript>alert('密码不能为空');javascript:history.back();</script>");
}
else
{
ResultSet rt=Conn.executeQuery("select username from test where username="+uname+"and pwd="+pwd+"");
if(!rt.next())
{
out.println("用户密码错误");
}
else
{
out.println("登陆成功!.");
}
}
}
%>
//<script language=javascript>alert('密码不能为空');javascript:history.back();</script>
请问哪里错误?
^^^^^^^^^^^^^^^^^^^^^^^^^SQL语句问题,好好看看!!
select pwd from test where username="+uname+"and pwd="+pwd+"";