Re: Problems with ResultSet

CachedRowSet does what you want to do.  There's a good explanation here:

http://www.onjava.com/pub/a/onjava/2004/06/23/cachedrowset.html


Ken

On Oct 28, 2005, at 5:38 AM, Aydın Toprak wrote:
>
> Ok you are right, that works... however I really dont understand why
> it fails...
> I though that I get all the results in my ResultSet obeject and keep
> it safe , distant  from closing connections or statements...
>
> as for returning my objects,
> I want all the result set .. so that I think,in these circumstances,
> there is no need to  generate my own objects and add them to the
> returning vector...
>
> am I mising a point?
>
>
>
>
>
> João Paulo Ribeiro wrote:
>
>> David is rigth.
>> And try to avoid returning resultset. If your method need to return
>> something do it with your own objects.
>> Do something like:
>>
>> -> get connection
>> -> create statement on the connection
>> -> execute statement and get resultset
>> -> iterate resultset and create your own object with the information
>> needed
>> -> close statement
>> -> return the object you created with the information from the
>> resultset
>>
>> Note:  if your using a pool always release the connection to the pool.
>>
>>
>> Regards.
>> João Paulo Ribeiro
>>
>>
>> David Goodenough wrote:
>>
>>> Closing the statement closes everything that came from it, i.e. the
>>> ResultSet.  So you need to delay closing the statement until after
>>> you have finished with
>>> the ResultSet.
>>>
>>> David
>>>
>>> On Friday 28 October 2005 11:18, Aydın Toprak wrote:
>>>
>>>> Hiii,
>>>>
>>>>
>>>> I have just stuck with a little point of my code which generates
>>>> "This
>>>> ResultSet is closed." exception ....
>>>>
>>>> here is my stack trace ...
>>>> org.postgresql.util.PSQLException: This ResultSet is closed.
>>>> org.postgresql.jdbc2.AbstractJdbc2ResultSet.checkClosed(AbstractJdbc
>>>> 2Result
>>>> Set.java:2444)
>>>>
>>>> org.postgresql.jdbc2.AbstractJdbc2ResultSet.next(AbstractJdbc2Result
>>>> Set.jav
>>>> a:1810)
>>>>
>>>> org.apache.jsp.event.Proposal.frameBuyer_jsp._jspService(org.apache.
>>>> jsp.eve
>>>> nt.Proposal.frameBuyer_jsp:61)
>>>>
>>>> org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
>>>> javax.servlet.http.HttpServlet.service(HttpServlet.java:802) ... and
>>>> continues...
>>>>
>>>>
>>>>
>>>> I want to return ResultSet from static method (I have never did
>>>> before,
>>>> I guess I can ..??.) ... I get resultset from my jsp page and want
>>>> to
>>>> display it ...
>>>> so ı wrote this database access staff into another class file to
>>>> sperate
>>>> them ... anyway..
>>>>
>>>>
>>>> try
>>>>           {
>>>>           stmnt = con.prepareStatement(query);
>>>>           stmnt.setInt(1, event_id);
>>>>           ps = stmnt.executeQuery();
>>>>           stmnt.close();
>>>>           connMgr.freeConnection("mypool", con);
>>>>           if(ps.next())
>>>>            out.append("This is your element
>>>> :"+ps.getInt("event_id"));
>>>>           }
>>>>
>>>> this is the part of the code wich generated that exception...
>>>>
>>>> as a result of my obeservations and try... I can directly point
>>>> that the
>>>> porblem comes from  this
>>>>          if(ps.next())
>>>>            out.append("This is your element
>>>> :"+ps.getInt("event_id"));
>>>>
>>>> part of the code...
>>>>
>>>>
>>>> but I dont understand why?.... the query is file, P.statement and
>>>> connection is exist ... and also there is an integer coloumn
>>>> "event_id"
>>>> in table...
>>>>
>>>> is it about the static method or what..? ..
>>>>
>>>> Thanks..
>>>>
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>>
>>
>> --
>> João Paulo Ribeiro | Senior Software Engineer
>> jp@mobicomp.com
>>
>> PHONE: + 351 253 305 250
>> FAX  : + 351 253 305 250
>> www.mobicomp.com
>>
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