SQL error

Hello all,
I have a ordersDone page for administrative use on a e-bookstore.Im trying to find the books selled retrieving the data from a database.This is my code:
<%
Connection con;
con = null;

try {
Class.forName("org.gjt.mm.mysql.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost/e_store");
}
catch (ClassNotFoundException e) {
}
catch (SQLException e) {
}

Statement stmtOrder = con.createStatement();
Statement stmtOrderProduct = con.createStatement();
Statement stmtProduct = con.createStatement();

ResultSet rsOrder = stmtOrder.executeQuery("Select * From Orders where OrderStatus = 'Done';");

while (rsOrder.next())
{
String CustomerID = rsOrder.getString("Customer_ID");
String OrderID = rsOrder.getString("Order_ID");
String AddressID = rsOrder.getString("Address_ID");
%>
<%=CustomerID%>----<%=OrderID%>------<%=AddressID%>
<%
ResultSet rsOrderProduct = stmtOrderProduct.executeQuery("select * from Order_Products where Order_ID = OrderID grouped by ProductID;");

while (rsOrderProduct.next())
{

String ProductID = rsOrder.getString("ProductID");
String ProdQuantity = rsOrderProduct.getString("ProductQuantity");
ResultSet rsProduct = stmtProduct.executeQuery("select * from Products where ISBN = ProductID;");
String Title = rsProduct.getString("Title");
%>
<%=ProductID%>-----<%=Title%>-----<%=ProdQuantity%>
<%
}
}
stmtOrder.close();
stmtOrderProduct.close();
stmtProduct.close();
rsOrder.close();
%>

i get null pointer exception though all my tables contain data..
leavung this to the experts.
thnx in advance
;)

productID & OrderID are string type variable. i am preety sure that these values are not inside in your Product_ID and Order_ID Field..

Please just use concatenate by "+" sign to comparing the value of its String type variable

JSP-JDBC Example
[ August 28, 2006: Message edited by: Saif Uddin ]

you were right about that.

Know i have in a other oage same sql error.Null pointer exception
my code is:
<%@ page contentType="text/html; charset=windows-1253" language="java" import="java.text.*,java.sql.*,java.util.*,javax.servlet.*,javax.servlet.http.*" %>
<html>

<head>
<meta http-equiv="Content-Type" content="text/html; charset=windows-1253">
<meta http-equiv="Content-Language" content="el">
<title>Books Selled by Category</title>
</head>

<body>

<p>
ISBN---------Τίτλος---------Τιμή Μονάδας---------Ποσότητα Πώλησης---------Γενικό Σύνολο
</p>

<%
Connection con;
con = null;

try {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn=DriverManager.getConnection("jdbc

dbc:BookstoreDatabase");
}
catch (ClassNotFoundException e) {
}
catch (SQLException e) {
log("sql exception");
}

Statement stmtProduct = con.createStatement();
ResultSet rsProduct = stmtProduct.executeQuery("Select * From ProductsInWarehouse;");

while (rsProduct.next())
{
String ISBN = rsProduct.getString("ISBN");
String TQS = rsProduct.getString("QuantitySelled");
int Quantity_Selled = Integer.parseInt(TQS);

Statement stmtPrice = con.createStatement();
ResultSet rsPrice = stmtPrice.executeQuery("select Title,Price from Products where ISBN ='" + ISBN + "';");

while(rsPrice.next())
{
String TP = rsPrice.getString("Price");
float Price = Float.parseFloat(TP);
String Title = rsPrice.getString("Title");
%>
<%=ISBN%>-------<%=Title%>-------<%=Price%>--------<%=Quantity_Selled%>-------<%=Price * Quantity_Selled%>
<%
}
}
rsProduct.close();
stmtProduct.close();
con.close();
%>
</body>
</html>

this code just lets the administrator view the books selled.Quantity and prices.
Thnx again in advance..

Aris,
Do you know what line the NullPointer is being thrown on?

I suspect there is a problem obtaining the connection. The code currently logs the exception and then continues with a null connection. You could test this theory, but putting everything in the try/catch block or by looking at the log.

Two other comments:
1) It is good practice to close the connection in a finally block. That way the connection is closed even if an exception is thrown. This allows the driver/database to better recover resources.
2) In a production application, it is good practice to keep code out of the JSP. Especially JDBC code. This makes the code easier to maintain.

When you see the bold highlighted text in the above code, you can trace out whats wrong. you are calling a method on a reference variable which is null (con).