Problem updating a table-row (changes are commited after "prerender()")

Question

Hi,
I hope someone can help me on this:
Background-info:
The page which gives me problems should (and is) displaying one record of a query at a time. Depending on the button which can be pressed, the page should just display the next entry ("Next->") or change one column of the current entry and jump to the next entry ("Wrong / Next->"). After the last entry, the query should be (and is) executed again and the page should display the first column, which fits the query-criterias.
The problem:
If the query just finds one record, the record is displayed on that page.
By pressing the "Next->" button, the page displays the same record again (like it should). By pressing the "Wrong / Next->" button, the page displays the same record again, although - like described above - one column was changed by that action and the query (which should and is executed again)
should not find that record anymore. By pressing the "Wrong / Next->" button again, the page is not displaying a record anymore (like I expected it from the first time pressing that button).
Technical Info:
I am using one DataProvider for the "select" and an other one for the "update".
Both are working fine.
The "select" is called in the method "prerender()" and the "update" is called in the action of the button "Wrong / Next->".
I debuged the program and found out, that the column of the database entry is changing it�s value not after processing the action of the button (like it should), but AFTER processing the method "prerender()". I tried to force the action of the button to commit the changes (xyDataProvider.commitChanges();), but without success.
Code:
public String buttonWrong_action() {
    try
        // Execute the Update-Statement
        sessionBean1.getXyRowSet().setObject(1, "2");
        sessionBean1.getXyRowSet().setObject(2, cardId);
        sessionBean1.getXyRowSet().setObject(3, operatorId);
        xyDataProvider.refresh();
    catch(Exception e)
    // Jump to the next record (set cursor)
public void prerender() {
    try
        // Execute the Select-Statement
        sessionBean1.getZRowSet().setObject(1, operatorId);
        sessionBean1.getZRowSet().setObject(4, resultId); // ResultId (1 = Right, 2 = Wrong)
        zDataProvider.refresh();
        zDataProvider.cursorFirst();
        cardId       = sessionBean1.getCardRowSet().getString("id");
    catch(Exception e)
}

Answer 1

I suggest you read and understand Joel's blogs -
http://blogs.sun.com/jfbrown
Creator's CachedRowSet is designed for SELECT statements (only) and updating the ResultSet you get from that SELECT statement.
(http://blogs.sun.com/jfbrown/entry/using_rowsets_for_crud_or )
dataprovider.refresh() does not re-execute the rowset's command. It just means to "clear the previous results".
(http://blogs.sun.com/jfbrown/entry/cachedrowsetdataprovider_and_cachedrowset_info )
So here's how cachedRowSet's are designed to work:
Set you rowset's command to:
SELECT resultid FROM cardresult
WHERE cardid = ?
AND operatorid = ?
They your code would do something like this:
dp.getCachedRowSet().setObject(1, ...) ;
dp.getCachedRowSet().setObject(2, ...) ;
dp.getCachedRowSet().release() ;  // clear last results.
boolean gotOne = dp.cursorFirst() ; // will cause execution
if ( gotOne ) {
    dp.setValue('resultid', '2') ;
    dp.commitChanges() ;
} else {
    error("can't update") ;
}You'll have to adjust that code - it's just a generic example.
Don't forget to add try/catch for a RuntimeException!
The alternative is to write your own JDBC.
You can use either.
Personally I'd just write a little helper class to assist me with using plain old JDBC for this.