我是新手啊,我把数据里的数据全取出来放在ArrayList里面了,但是我想让km(数据库第十列)这一列的数求和,然后把结果显示在jsp页面上,该怎么做?jsp页面上怎么接收?拜求各位大神帮忙指导啊。我具体的servlet代码如下。有count的地方都报错了,说是count cannot be resolved to a variable。
try{
Connection conn=null;
Statement st=null;
Class.forName("com.mysql.jdbc.Driver");
conn =DriverManager.getConnection("jdbc:mysql://localhost:3306/test?user=root&password=");
st =conn.createStatement();
String sql1="select sum(km) as count from jixiao2;"
st.execute(sql);
} catch (Exception e)
{
e.printStackTrace();
}
try
{
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection(DBURL,DBUSER,DBPASS);
ResultSet rssumkm1=stmt.executeQuery(sql1);
ResultSet rs=pstmt.executeQuery();
while(rs.next())
{
Jixiao jx=new Jixiao();
jx.setKm(rs.getInt(10));
jx.setAllowance(rs.getInt(11));
jx.setCount(rssumkm1.getInt(count));
list.add(jx);
}
request.setAttribute("Count", count);
request.setAttribute("list", list);
request.getRequestDispatcher("Showlist.jsp").forward(request, response);
改了,改成sumkm,还是不行呢,还是报错sumkm cannot be resolved to a variable
追答sum(km) as count
?
你就不要用count这个变量
问题已经解决了,不是这个问题的,用request.setAttribute("sumkm",(rs.getString(1)));就能传出去,jsp文件就用接收就行。虽然你的回答没有解决问题,不过也是对我解决问题有帮助的,谢谢了。