Re: "This ResultSet is closed" exception on a PreparedStatement getMetaData()

Hi Emmanuel,

I've just pushed a fix into master for this. Thanks!

Dave Cramer

dave.cramer(at)credativ(dot)ca
http://www.credativ.ca

On Thu, Dec 19, 2013 at 9:20 AM, Dave Cramer <pg(at)fastcrypt(dot)com> wrote:

> Hi Emmanuel,
>
> That's what I get for answering without checking the code! You are correct
> and it does seem like a bug, and fairly easily fixed. I'll echo Kevin's
> sentiments here.
>
> Thanks!
>
> Dave Cramer
>
> dave.cramer(at)credativ(dot)ca
> http://www.credativ.ca
>
>
> On Thu, Dec 19, 2013 at 9:06 AM, Emmanuel GUITON <
> Emmanuel(dot)GUITON(at)intrinsec(dot)com> wrote:
>
>> Hi Dave,
>>
>> I am a bit surprised with what you say since in the test case I provided,
>> I call getMetaData() on the PreparedStatement without having ever
>> executed the PreparedStatement itself to get the ResultSet. And it works.
>> Do you mean that under the hook the PreparedStatement executes a query to
>> be able to fetch the metadata ? (Then what would it be since a ResultSet
>> could not be fetched without parameter values when the query has
>> parameters.)
>>
>> Unfortunately, I do not know if this behavior is consistent with previous
>> versions of the JDBC driver.
>>
>> Regards,
>> - Emmanuel
>>
>>
>>
>> *Emmanuel GUITON*
>>
>> *Ingénieur Développement *
>> Fixe : +33170928416 l Standard : +33141917777
>>
>> 215, avenue Georges Clemenceau l 92024 Nanterre
>>
>> <http://www.forum-fic.com/2014/fr/inscription-fic/>
>> <http://www.intrinsec.com/>
>>
>>
>>
>> ------------------------------
>> *From:* davecramer(at)gmail(dot)com <davecramer(at)gmail(dot)com> on behalf of Dave
>> Cramer <pg(at)fastcrypt(dot)com>
>> *Sent:* Thursday, December 19, 2013 2:35 PM
>> *To:* Emmanuel GUITON
>> *Cc:* pgsql-jdbc(at)postgresql(dot)org
>> *Subject:* Re: [JDBC] "This ResultSet is closed" exception on a
>> PreparedStatement getMetaData()
>>
>>
>> Emmanuel,
>>
>> The assumption that the spec makes about the prepared statement being
>> compiled are not valid for PostgreSQL. The metadata comes from the result
>> set, not from the statement. You could in fact not call getMetaData on a
>> statement which was not executed.
>>
>> That being said, do you know if this behaviour is consistent with
>> previous versions of the JDBC driver ?
>>
>> Dave Cramer
>>
>> dave.cramer(at)credativ(dot)ca
>> http://www.credativ.ca
>>
>>
>>
>>
>> ------------------------------
>>
>> On Thu, Dec 19, 2013 at 4:33 AM, Emmanuel GUITON <
>> Emmanuel(dot)GUITON(at)intrinsec(dot)com> wrote:
>>
>>> Hello,
>>>
>>> I ran into troubles fetching metadata on a PreparedStatement. After some
>>> time, I isolated a simple test case that shows the issue (see the code
>>> snippet below). On a brand new PreparedStatement, I call the getMetaData()
>>> method without any problem. However, if I execute the query
>>> (executeQuery()) on this same statement, close the ResultSet and then calls
>>> again
>>> getMetaData() (still on the same PreparedStatement), getMetaData()
>>> throws a RuntimeException saying "This ResultSet is closed".
>>> I would expect to be able to get the metadata. Is that a bug in the JDBC
>>> driver ?
>>>
>>> I tested this behavior on several flavours of the 9.3 driver version,
>>> including 9.3-1100-jdbc4 .
>>>
>>> Regards,
>>> - Emmanuel
>>>
>>>
>>> package test;
>>>
>>> import java.sql.Connection;
>>> import java.sql.DriverManager;
>>> import java.sql.PreparedStatement;
>>> import java.sql.ResultSet;
>>> import java.sql.ResultSetMetaData;
>>> import java.sql.SQLException;
>>> import junit.framework.Assert;
>>> import org.testng.annotations.Test;
>>>
>>> /**
>>> * Test on the PostgreSql JDBC driver.
>>> */
>>> public class JdbcTest
>>> {
>>> /**
>>> * This test shows a driver issue on the PreparedStatement
>>> management.
>>> *
>>> * @throws ClassNotFoundException On driver initialization failure.
>>> * @throws SQLException On datbase operation failure.
>>> */
>>> @Test
>>> public void test2()
>>> throws SQLException, ClassNotFoundException
>>> {
>>> Class.forName("org.postgresql.Driver");
>>> final Connection connection =
>>> DriverManager.getConnection("jdbc:postgresql://server/db_name", "username",
>>> "password");
>>>
>>> final String query = "SELECT 1 AS toto, 2 AS titi";
>>>
>>> final PreparedStatement pstmt =
>>> connection.prepareStatement(query);
>>> final ResultSetMetaData rsMetadata = pstmt.getMetaData();
>>> Assert.assertNotNull(rsMetadata);
>>>
>>> final ResultSetMetaData rsMetadata2 = pstmt.getMetaData();
>>> Assert.assertNotNull(rsMetadata2);
>>>
>>> final ResultSet rs = pstmt.executeQuery();
>>> Assert.assertNotNull(rs);
>>> rs.close();
>>>
>>> Assert.assertFalse(pstmt.isClosed());
>>> try
>>> {
>>> // Guess what ? The next line throws an exception !
>>> final ResultSetMetaData rsMetadata3 = pstmt.getMetaData();
>>> Assert.assertNotNull(rsMetadata3);
>>> }
>>> catch (final RuntimeException exception)
>>> {
>>> Assert.fail(exception.getMessage());
>>> }
>>> pstmt.close();
>>>
>>> connection.close();
>>> }
>>> }
>>>
>>>
>>>
>>>
>>> *Emmanuel GUITON*
>>>
>>> *Ingénieur Développement *
>>> Fixe : +33170928416 l Standard : +33141917777
>>>
>>> 215, avenue Georges Clemenceau l 92024 Nanterre
>>>
>>> <http://http://www.forum-fic.com/2014/fr/inscription-fic/>
>>> <http://www.intrinsec.com/>
>>>
>>>
>>>
>>>
>>
>