Customer Validation Inside a Servlet...

Question

I am having some trouble getting the code correct to see whether the customer exists in the database, and if so, not inserting a new record. Otherwise, I just want to update the orders. Any suggestions would be greatly appreciated, I am new to Java! here is a pc of the code that is not working correctly. Thanks....
String firstname = req.getParameter("firstname");
String lastname = req.getParameter("lastname");
boolean isCustid =false;
String queryFirstLast = "SELECT firstname, lastname from CUSTOMERS";
ResultSet rs = executeQuery(queryFirstLast);
while(isCustId==false){
rs.next();
if(!rs.getString.equals(firstname)&(!rs.getString.equals(lastname))){
String insertNewCust = "INSERT INTO CUSTOMERS("firstname", "lastname", etc...
VALUES("+firstname+", "+lastname+" etc...
}else{
update order code...
isCustid =true;
Again, I would appreciate any comments...Thank you!

Answer 1

Hi
Use something like this:
PreparedStatement pStmt = con.prepareStatement("SELECT * FROM TABLE WHERE Firstname =? AND Lastname =?");
  pStmt.setString(1, firstname);
  pStmt.setString(2, lastname);
  ResultSet rs = pStmt.executeQuery();
  //System.out.println("sql : "+pStmt);
  try{
  if(!rs.next()){
     System.out.println("User not found");
  else do{
     System.out.println("User found");
  }while (rs.next());Andreas