You are viewing a plain text version of this content. The canonical link for it is here.
Posted to derby-dev@db.apache.org by "Johannes Lichtenberger (JIRA)" <ji...@apache.org> on 2014/09/08 15:30:29 UTC
[jira] [Comment Edited] (DERBY-6728) Reading from a Clob fails.
[ https://issues.apache.org/jira/browse/DERBY-6728?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14125469#comment-14125469 ]
Johannes Lichtenberger edited comment on DERBY-6728 at 9/8/14 1:30 PM:
-----------------------------------------------------------------------
However, I'm curious why the SELECT-statements makes the connection auto-commit (as it's just a SELECT-statement and doesn't modify/insert any data). Also it seems that a repeated call getClob(...) on the result set is possible in other DBMs.
Despite, I was able to fix the problem with your suggestion to set autocommit to false and with a simple map to map column-names to Clobs in order to prevent from repeatedly calling getClob(...) on the same result set so thank you.
was (Author: johannes.lichtenberger):
However, I'm curious why the SELECT-statements makes the connection auto-commit (as it's just a SELECT-statement and doesn't modify/insert any data). Also it seems that a repeated call getClob(...) on the resul set is possible in other DBMs.
Despite, I was able to fix the problem with your suggestion to set autocommit to false and with a simple map to map column-names to Clobs in order to prevent from repeatedly calling getClob(...) on the same result set so thank you.
> Reading from a Clob fails.
> --------------------------
>
> Key: DERBY-6728
> URL: https://issues.apache.org/jira/browse/DERBY-6728
> Project: Derby
> Issue Type: Bug
> Components: SQL
> Affects Versions: 10.11.1.1
> Reporter: Johannes Lichtenberger
>
> In the Java-Code below the reading from a CLOB-column fails with an SQLException. It somehow seems to be related to reading the maximum integer primary key value beforehand.
> import java.sql.Clob;
> import java.sql.Connection;
> import java.sql.DriverManager;
> import java.sql.PreparedStatement;
> import java.sql.ResultSet;
> import java.sql.Statement;
> public class DerbyClobTest
> {
> public static void main(String[] args)
> {
> try
> {
> Connection conn = DriverManager
> .getConnection("jdbc:derby://localhost:1527/database;user=derby;password=derby");
> Statement stmt = conn.createStatement();
> ResultSet rs = stmt.executeQuery("SELECT * FROM APP");
> while (rs.next())
> {
> PreparedStatement l_stmt = null;
> int l_iMaxLid = -1;
> try
> {
> l_stmt = conn.prepareStatement("SELECT MAX(LID) FROM APP");
> ResultSet l_rs = l_stmt.executeQuery();
> try
> {
> if (l_rs.next())
> l_iMaxLid = l_rs.getInt(1);
> }
> finally
> {
> l_rs.close();
> l_rs = null;
> }
> }
> finally
> {
> l_stmt.close();
> l_stmt = null;
> }
> PreparedStatement stmtNew = conn
> .prepareStatement("INSERT INTO APP(LID, TXTBODY) VALUES(?, ?)");
> stmtNew.setInt(1, l_iMaxLid);
> final Clob clob = rs.getClob("TXTBODY");
> if (clob == null)
> return;
> final String str = clob.getSubString(1, (int) clob.length());
> // Do something with str.
> stmtNew.setClob(2, clob);
> stmtNew.executeUpdate();
> stmtNew.close();
> }
> }
> catch (Exception except)
> {
> except.printStackTrace();
> }
> }
> }
> Stacktrace:
> java.sql.SQLException: Es können keine weiteren java.sql.Clob/java.sql.Blob-Methoden aufgerufen werden, nachdem die free()-Methode aufgerufen oder nachdem die Blob/Clob-Transaktion ausgeführt oder wiederholt (Rollback) wurde.
> at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
> at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
> at org.apache.derby.client.am.Clob.length(Unknown Source)
> at de.uplanet.lucy.server.calendar.DerbyClobTest.main(DerbyClobTest.java:73)
> Caused by: org.apache.derby.client.am.SqlException: Es können keine weiteren java.sql.Clob/java.sql.Blob-Methoden aufgerufen werden, nachdem die free()-Methode aufgerufen oder nachdem die Blob/Clob-Transaktion ausgeführt oder wiederholt (Rollback) wurde.
> at org.apache.derby.client.am.CallableLocatorProcedures.handleInvalidLocator(Unknown Source)
> at org.apache.derby.client.am.CallableLocatorProcedures.clobGetLength(Unknown Source)
> at org.apache.derby.client.am.Clob.getLocatorLength(Unknown Source)
> at org.apache.derby.client.am.Lob.sqlLength(Unknown Source)
> ... 2 more
> Caused by: org.apache.derby.client.am.SqlException: Bei der Auswertung eines Ausdrucks wurde die Ausnahme 'java.sql.SQLException: Der für dieses CLOB/BLOB angegebene Locator ist ungültig' ausgelöst.
> at org.apache.derby.client.am.Statement.completeExecute(Unknown Source)
> at org.apache.derby.client.net.NetStatementReply.parseEXCSQLSTTreply(Unknown Source)
> at org.apache.derby.client.net.NetStatementReply.readExecuteCall(Unknown Source)
> at org.apache.derby.client.net.StatementReply.readExecuteCall(Unknown Source)
> at org.apache.derby.client.net.NetStatement.readExecuteCall_(Unknown Source)
> at org.apache.derby.client.am.Statement.readExecuteCall(Unknown Source)
> at org.apache.derby.client.am.PreparedStatement.flowExecute(Unknown Source)
> at org.apache.derby.client.am.PreparedStatement.executeX(Unknown Source)
> ... 5 more
> Caused by: org.apache.derby.client.am.SqlException: Der für dieses CLOB/BLOB angegebene Locator ist ungültig
> ... 13 more
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)