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From Sai Pullabhotla <sai.pullabho...@jmethods.com>
Subject Re: Strange SQLException when trying to read existing row
Date Mon, 17 Aug 2009 16:20:05 GMT
It might help if you actually post the full source code and the stack
trace of the exception.

Thanks.

Sai Pullabhotla
www.jMethods.com




On Mon, Aug 17, 2009 at 10:26 AM, Dominik
Jednoralski<twelve02@googlemail.com> wrote:
> Hi Sai,
>
> many thanks for your response. Actually, I polished the code before
> publishing to the mailing list. My original code at the position of the
> error looked like this
>
> if (result != null) {
>                 if (result.next()) {
>                 // breaks with sql-exception: no such row
>                 String data = result.getString(1);
>
> result.next() at this position always reports an empty ResultSet.
>
> Best
>
> Dominik
>
>
> 2009/8/17 Sai Pullabhotla <sai.pullabhotla@jmethods.com>
>>
>> When a ResultSet is produced, the cursor is positioned before the
>> first row. You must call ResultSet.next() method to move the cursor to
>> the first row and then the ResultSet.getXXX methods for each column.
>> Can you verify/confirm if your code is setup to do this?
>>
>> Thanks.
>>
>> Sai Pullabhotla
>> www.jMethods.com
>>
>>
>>
>>
>> On Sun, Aug 16, 2009 at 5:04 PM, Dominik
>> Jednoralski<twelve02@googlemail.com> wrote:
>> > Hi Geeks,
>> >
>> > I'm integrating the derby-database into a JAVA-driven web application.
>> > I'm
>> > new to derby and I have a problem with the execution of a
>> > SELECT-statement.
>> > The returned ResultSet is empty, although the selected row is definitely
>> > stored.
>> >
>> > The code below works, creates a new table and inserts a dummy row.
>> >
>> > CREATE TABLE gaps (gapId int generated by default as identity,
>> > MBaseId VARCHAR(256), important INTEGER DEFAULT 0,
>> > ignore INTEGER DEFAULT 0, data LONG VARCHAR,
>> > creation TIMESTAMP, lastModified TIMESTAMP)
>> > INSERT INTO gaps (data) VALUES ('foo')
>> >
>> > At this position, the row is accessible and everything is fine. Later,
>> > when
>> > I want to retrieve this very row via the follwing code, it breaks
>> > because
>> > the ResultSet is empty. The methods are both members of the same class
>> > and
>> > share the connection and statement, which both are class members.
>> >
>> >  ResultSet result = statement.executeQuery("SELECT data "
>> >                         + "FROM gaps WHERE gapId = 1"
);
>> >
>> >             if (result != null) {
>> >
>> >                 // breaks with sql-exception: no such row
>> >                 String data = result.getString(1);
>> >
>> >
>> > Can anyone of you help me with this? I'm pretty confused. Thanks a lot
>> > in
>> > advance =)
>> >
>> > best
>> >
>> > Dominik
>
>

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