First the query runs, then it doesn't...

Question

Hi!
I have a problem that I can't figure out. Consider the following code:
try {
               stmt = conn.createStatement();
               rs1 = stmt.executeQuery("SELECT * FROM tbl_Ordklass");
               while (rs1.next()) {
                    //Stoppa in ordklasserna p� webbsidan
                    String ordklassnr = rs1.getString(1);
                    String ordklass = rs1.getString(2);
                    m.add("<!--===ordklassListbox===-->", "==ordklassvarde==",
                              ordklassnr);
                    m.add("<!--===ordklassListbox===-->", "==ordklass==", ordklass);
               stmt = conn.createStatement();
               rs2 = stmt.executeQuery("SELECT * FROM tbl_genus");
               while (rs2.next()) {
                    //Stoppa in genusformerna p� webbsidan
                    String genusnummer = rs2.getString(1);
                    String genus = rs2.getString(2);
                    m.add("<!--genusListbox-->", "<!--genusvarde-->",
                              genusnummer);
                    m.add("<!--genusListbox-->", "<!--genus-->", genus);
          } catch (SQLException ex2) {
               log("ex2: " + ex2.getMessage());
               log(ex2.getSQLState());
          } catch (NullPointerException e401) {
               log("e401= " + e401.getLocalizedMessage());
          try{
               stmt = conn.createStatement();               
               rs = stmt.executeQuery("SELECT * FROM tbl_Ordklass");/*stmt.executeQuery("SELECT " +
                         "ok.PK_ordklassnr, ok.txt_ordklass " +
                         "FROM " +
                         "tbl_Ordklass AS ok, tbl_Ord AS o " );
                         //"WHERE " +
                         //"ok.PK_ordklassnr = o.PK_orklassnr " +
                         //"AND " +
                         //"o.PK_ordnummer = "+ strOrdnummer);
               while(rs.next()){
                    String ordklassnr = rs1.getString(1);
                    String ordklass = rs1.getString(2);
                    m.add("<!--===ordklassListbox===-->", "==ordklassvarde==",
                              ordklassnr);
                    m.add("<!--===ordklassListbox===-->", "==ordklass==", ordklass);
          catch(SQLException ex417){
               log("ex417 = " + ex417.getLocalizedMessage());
               log("ex417 = " + ex417.getSQLState());
               log("ex417 = " + ex417.getCause());
          }I generates the following errors:
2005-04-23 20:27:56 AdminServlet: ex417 = [Microsoft][SQLServer 2000 Driver for JDBC]Invalid operation for the current cursor position.
2005-04-23 20:27:56 AdminServlet: ex417 = 24000
2005-04-23 20:27:56 AdminServlet: ex417 = nullSo the problem is that the same query first runs fine, and then it doesn't. Why?
I think it's someting very basic, but I turn to you since I don't have anyone to ask.
I can't understand this.
Please help
Regards
Jonas Karlsson

Answer 1

Hi!
I have a problem that I can't figure out. Always close result sets, statements and connections when you a through with them. And close them in that order.
You should limit variables to the scope in which they are used as well.
As for your problem....
In the second code block.
while(rs.next()){
String ordklassnr = rs1.getString(1);If you limited your variables to the scope that you were using then the above would have been apparent.