Javascript random number

Dear Sir,
I have a table with many coloumns with one coloumn as vacant corresponding to every row.All coloumns are retreived from database.I have to generate random numbers corresponding to every row.But problem is one constraint is there while generating random numbers.If there is 60 rows,i have to do 60/10=6 groups of those rows.group-1,2,3,4,5,6.Under one group there will be 10 rows and their random numbers will be same.Then next 10 rows' random numbers will be same.coloumn name is LOT NO.After displaying that table with that vacant coloumn,then there will be one button generate lot no.After clickin on that button numbers will be generated along with updation in the database for the LOT_NO coloumn in the database.

e.g:-I have a table for students' details in a school.unique is their roll number in rows.coloumns are age,sex,grade etc.There is one coloumn vacant for lot no.I want to place equal number of students under one lot number.Then same numbers under another.If there is 60 stuednts.Group them as a,b,c,d,e,f.six group.60/10=6.For the first 10 studets lot no should be generated randomly and should be same.Next 10 students should have same lot no with random generation.I want that random function with its implementation.After clicking the button javascript should create random numbers as i have mentioned above.
Age Sex Location Lot No
Roll No
452345 4 M ty Empty
545454 6 M 5y Empty
767568 7 M hy Empty
203392 9 M ty Empty

After clickig on generate numbers random numbers should be generated.But First two students should have same random numbers and second two should have another same numbers.Likewise we can create for 20,30,40 students.

Please help me
Regards
Debasis Mohapatra

View Answers

July 13, 2010 at 5:58 PM

Hi Friend,

Try the following code:

<%@ page language="java" %>
<%@ page import="java.sql.*" %>
<%@ page import="java.util.*" %>
<%!
public int nullIntconvert(String str){
int num=0;
if(str==null) {
str="0";
}
else if((str.trim()).equals("null")) {
str="0";
}
else if(str.equals("")) {
str="0";
}
try{
num=Integer.parseInt(str);
}
catch(Exception e) { }
return num;
}
%>
<%
Connection conn = null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root";, "root");
ResultSet rs1 = null;
ResultSet rs2 = null;
PreparedStatement ps1=null;
PreparedStatement ps2=null;

int showRows=10;
int totalRecords=10;
int totalRows=nullIntconvert(request.getParameter("totalRows"));
int totalPages=nullIntconvert(request.getParameter("totalPages"));
int iPageNo=nullIntconvert(request.getParameter("iPageNo"));
int cPageNo=nullIntconvert(request.getParameter("cPageNo"));

int startResult=0;
int endResult=0;
if(iPageNo==0){
iPageNo=0;
}
else{
iPageNo=Math.abs((iPageNo-1)*showRows);
}
String query1="SELECT SQL_CALC_FOUND_ROWS * FROM student limit "+iPageNo+","+showRows+"";
ps1=conn.prepareStatement(query1);
rs1=ps1.executeQuery();
String query2="SELECT FOUND_ROWS() as cnt";
ps2=conn.prepareStatement(query2);
rs2=ps2.executeQuery();
if(rs2.next()) {
totalRows=rs2.getInt("cnt");
System.out.println(totalRows);
}
%>
<html>
<h3>Pagination of JSP page</h3>
<body>
<form method="post" action="update.jsp">
<input type="hidden" name="iPageNo" value="<%=iPageNo%>">
<input type="hidden" name="cPageNo" value="<%=cPageNo%>">
<input type="hidden" name="showRows" value="<%=showRows%>">
<table width="100%" cellpadding="0" cellspacing="0" border="1" >
<tr>
<td>Roll No</td>
<td>Name</td>
<td>Marks</td>
<td>Grade</td>
<td>Lot No</td>
</tr>
<%
Random r=new Random();
int ran=r.nextInt(10);
while(rs1.next()){
%>
<tr>
<td><input type="text" name="roll" value="<%=rs1.getInt("rollNo")%>"></td>
<td><input type="text" name="name" value="<%=rs1.getString("name")%>"></td>
<td><input type="text" name="marks" value="<%=rs1.getInt("marks")%>"></td>
<td><input type="text" name="grade" value="<%=rs1.getString("grade")%>"></td>
<td><input type="text" name="lotNo" value="<%=ran%>"></td>
</tr>

July 13, 2010 at 5:59 PM

continue..

<%
}
%>
<%
try{
if(totalRows<(iPageNo+showRows)) {
endResult=totalRows;
}
else{
endResult=(iPageNo+showRows);
}
startResult=(iPageNo+1);
totalPages=((int)(Math.ceil((double)totalRows/showRows)));
}
catch(Exception e){
e.printStackTrace();
}
%>
<tr>
<td colspan="3">
<div>
<%
int i=0;
int cPage=0;
if(totalRows!=0) {
cPage=((int)(Math.ceil((double)endResult/(totalRecords*showRows))));
int prePageNo=(cPage*totalRecords)-((totalRecords-1)+totalRecords);
if((cPage*totalRecords)-(totalRecords)>0){
%>
<a href="pagination.jsp?iPageNo=<%=prePageNo%>&cPageNo=<%=prePageNo%>"> << Previous</a>
<%
}
for(i=((cPage*totalRecords)-(totalRecords-1));i<=(cPage*totalRecords);i++){
if(i==((iPageNo/showRows)+1)){%>
<a href="pagination.jsp?iPageNo=<%=i%>" style="cursor:pointer;color: red"><b><%=i%></b></a>
<%
}
else if(i<=totalPages){
%>
<a href="pagination.jsp?iPageNo=<%=i%>"><%=i%></a>
<%
}
}
if(totalPages>totalRecords && i<totalPages){
%>
<a href="pagination.jsp?iPageNo=<%=i%>&cPageNo=<%=i%>"> >> Next</a>
<%
}
}
%>
<b>Rows <%=startResult%>-<%=endResult%>Total Rows<%=totalRows%> </b>
</div>
</td>
</tr>
</table>
<input type="submit" value="Update">
</form>
</body>
</html>
<%
try{
if(ps1!=null){
ps1.close();
}
if(rs1!=null){
rs1.close();
}

if(ps2!=null){
ps2.close();
}
if(rs2!=null){
rs2.close();
}
if(conn!=null){
conn.close();
}
}
catch(Exception e)
{
e.printStackTrace();
}
%>

update.jsp:

<%@page import="java.sql.*"%>
<%
String d[] =request.getParameterValues("roll");
String name[] =request.getParameterValues("name");

String marks[] =request.getParameterValues("marks");

String grade[] =request.getParameterValues("grade");

String lotNo[] =request.getParameterValues("lotNo");

%>
<%
try{
Connection conn = null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root";, "root");

Statement st=null;
st=conn.createStatement();
for(int a=0;a<10;a++){
String no=d[a];
String tit=name[a];
String mar=marks[a];
String gra=grade[a];
String lot=lotNo[a];
st.executeUpdate("update student set rollNo='"+no+"', name='"+tit+"',marks='"+mar+"',grade='"+gra+"',lotNo='"+lot+"' where rollNo='"+no+"'");
}
}
catch(Exception e){
e.printStackTrace();
}
response.sendRedirect("pagination.jsp");
%>

Thanks