解决办法：
我用ASP做过类似的功能，，第一步：
用JSP把数据库中表的字段得到，，java.sql.* 有实现操作的类，，
<%
for{%>
<input type=checkbox name="colName" value="<%=colName%>"><%=colName%>
<%}%>
第二步
当checkbox被选择时检测有多些checkbox被选，，大于30时，提示，，，
之后提交，，
第三步
接收String array=request.getParameterValues("colName");
String col_sql="";
for(int i=0;i<array.length-1;i++){
col_sql+=array[i]+",";
}
col_sql+=array[i];sql="select "+col_sql+" form table ....."
我用ASP做过类似的功能，，第一步：
用JSP把数据库中表的字段得到，，java.sql.* 有实现操作的类，，
<%
for{%>
<input type=checkbox name="colName" value="<%=colName%>"><%=colName%>
<%}%>
第二步
当checkbox被选择时检测有多些checkbox被选，，大于30时，提示，，，
之后提交，，
第三步
接收String array=request.getParameterValues("colName");
String col_sql="";
for(int i=0;i<array.length-1;i++){
col_sql+=array[i]+",";
}
col_sql+=array[i];sql="select "+col_sql+" form table ....."
<HTML>
<HEAD>
<TITLE>自定义统计表</TITLE>
<script language="javascript" src="../include/input.js"></script>
<SCRIPT language=JavaScript><!-- Begin
sortitems = 1; // Automatically sort items within lists? (1 or 0)function move(fbox,tbox) {
for(var i=0; i<fbox.options.length; i++) {
if(fbox.options[i].selected && fbox.options[i].value != "") {
//alert (i);
if (tbox.options.length==0){
abc(fbox,tbox,i);
}
else{
for(var m=0; m<tbox.options.length; m++) {
//alert (m);
//alert (fbox.options[i].text);
//alert (tbox.options[m].text);
if (fbox.options[i].value==tbox.options[m].value){
//alert("kkk");
return false;
}
}
abc(fbox,tbox,i);
}
}
}
BumpUp(fbox);
if (sortitems) SortD(tbox);
}function abc(fbox,tbox,num)
{
var no = new Option();
no.value = fbox.options[num].value;
no.text = fbox.options[num].text;
tbox.options[tbox.options.length] = no;
}function formsub(){if (window.event.keyCode==13){submit1.click();
}}function addvaluetext(){
var str=formviewarea.begintime.value;
var str1=formviewarea.endtime.value;
if (document.formviewarea.list2.options.length<1)
{
window.setTimeout('alert("不能提交空景区")',50);
return false;
}
if (str==""){
alert("开始日期不能未空");
return false;
}
if (str1==""){
alert("结束日期不能未空");
return false;
}
document.formviewarea.hiddentext1.value="";
document.formviewarea.hiddentext2.value=""; for(var i=0; i<document.formviewarea.list2.options.length; i++)
{
if (document.formviewarea.hiddentext1.value==""){
document.formviewarea.hiddentext1.value=document.formviewarea.list2.options[i].value;
}
else{
document.formviewarea.hiddentext1.value=document.formviewarea.hiddentext1.value+","+document.formviewarea.list2.options[i].value;
}
if (document.formviewarea.hiddentext2.value==""){
document.formviewarea.hiddentext2.value=document.formviewarea.list2.options[i].text;
}
else{
document.formviewarea.hiddentext2.value=document.formviewarea.hiddentext2.value+","+document.formviewarea.list2.options[i].text;
}
}
}
/*mys:此函数是去掉已选择字段空值，并计算已选择字段列表的长度*/
function BumpUp(box) {
for(var i=0; i<box.options.length; i++) {
if(box.options[i].value =="")
{
for(var j=i; j<box.options.length-1; j++)
{
box.options[j].value = box.options[j+1].value;
box.options[j].text = box.options[j+1].text;
}
var ln = i;
break;
}
}
if(ln < box.options.length) {
box.options.length -= 1;
BumpUp(box);
}
}/*mys:排序*/
function SortD(box) {
var temp_opts = new Array();
var temp = new Object();
for(var i=0; i<box.options.length; i++)
{
temp_opts[i] = box.options[i];
}
for(var x=0; x<temp_opts.length-1; x++)
{
for(var y=(x+1); y<temp_opts.length; y++)
{
if(temp_opts[x].text > temp_opts[y].text)
{
temp = temp_opts[x].text;
temp_opts[x].text = temp_opts[y].text;
temp_opts[y].text = temp;
temp = temp_opts[x].value;
temp_opts[x].value = temp_opts[y].value;
temp_opts[y].value = temp;
}
}
}
for(var i=0; i<box.options.length; i++) {
box.options[i].value = temp_opts[i].value;
box.options[i].text = temp_opts[i].text;
}
}
// End -->
</SCRIPT><SCRIPT language=javascript>
<!--
sortitems = 1;
function delete1(tbox){
for (var i=0;i<document.formviewarea.list2.options.length;i++){
if (document.formviewarea.list2.options[i].selected){
document.formviewarea.list2.options[i].value="";
document.formviewarea.list2.options[i].text="";
}
}
BumpUp(tbox);
if (sortitems) SortD(tbox);
}
//-->
</SCRIPT><SCRIPT language=JavaScript type=text/javascript>
<!--
var ggg=0;
function change(uuu)
{
for (var i=0;i<document.formviewarea.list2.options.length;i++){
document.formviewarea.list2.options[i].value="";
document.formviewarea.list2.options[i].text="";
}
BumpUp(formViewArea.list2);
if (1) SortD(formViewArea.list2);var zzz= "div"+uuu;
if (ggg>0)
{
oldObj.style.display="none";
}
else{
div1.style.display="none";
}
document.all(zzz).style.display="";
oldObj=document.all(zzz);
ggg+=1; var table = new Array('T4','T9','T10','T11');
with(document.formA)
{
for (i=0;i<radioprovince.length;i++)
{
if (radioprovince[i].checked)
{
document.formviewarea.hiddentext0.value = table[i];
}
}
}
} function jdreturn(){
radio1.checked=true;
if (hiddcontent1.style.display=="" && hiddcontent2.style.display==""){
hiddcontent1.style.display="none";
hiddcontent2.style.display="none";
}
}
//-->
</SCRIPT>
<META content="text/html; charset=gb2312" http-equiv=Content-Type>
<META content="" name=Keywords><LINK href="../include/tjextend.css" rel=stylesheet
type=text/css>
<STYLE media=screen type=text/css>DIV {
POSITION: relative
}
</STYLE><META content="MSHTML 5.00.3315.2870" name=GENERATOR></HEAD>