Polymorphic query with set first row and limit result set returns wrong results ------------------------------------------------------------------------------- Key: HHH-3542 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-3542 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.2.0.ga Reporter: Yevgeny Shakhnovich If we issue a polymorphic query with the specified first row and set max rows to retrieve, the query returns wrong results. For example, you have two entities A and B implementing the same interface C. Query query = session.createQuery("from C"); query.setMaxResults(10); query.setFirstResult(10); List<Object[]> result = query.list(); // will return only two records despite of tables A and B have enough records The bug is pretty simple: the same variable is used to count total number of records and included records.This is the excerpt from org.hibernate.engine.query.HQLQueryPlan.performList int includedCount = -1; translator_loop: for ( int i = 0; i < translators.length; i++ ) { List tmp = translators[i].list( session, queryParametersToUse ); if ( needsLimit ) { // NOTE : firstRow is zero-based int first = queryParameters.getRowSelection().getFirstRow() == null ? 0 : queryParameters.getRowSelection().getFirstRow().intValue(); int max = queryParameters.getRowSelection().getMaxRows() == null ? -1 : queryParameters.getRowSelection().getMaxRows().intValue(); final int size = tmp.size(); for ( int x = 0; x < size; x++ ) { final Object result = tmp.get( x ); if ( !distinction.add( result ) ) { continue; } // In example above first is 10 and max is 10 as well. includedCount++; if ( includedCount < first ) { continue; } // This point is reached only when includedCount is 10 or more combinedResults.add( result ); if ( max >= 0 && includedCount > max ) { // break the outer loop !!! break translator_loop; } The fix is also simple: add one more variable to keep the total number of records: int includedCount = 0; int recordCount = 0; translator_loop: for ( int i = 0; i < translators.length; i++ ) { List tmp = translators[i].list( session, queryParametersToUse ); if ( needsLimit ) { // NOTE : firstRow is zero-based int first = queryParameters.getRowSelection().getFirstRow() == null ? 0 : queryParameters.getRowSelection().getFirstRow().intValue(); int max = queryParameters.getRowSelection().getMaxRows() == null ? -1 : queryParameters.getRowSelection().getMaxRows().intValue(); final int size = tmp.size(); for ( int x = 0; x < size; x++ ) { final Object result = tmp.get( x ); if ( !distinction.add( result ) ) { continue; } /* includedCount should include only what was really included */ if ( recordCount++ < first) { continue; } includedCount++; combinedResults.add( result ); if ( max >= 0 && includedCount >= max ) { // break the outer loop !!! break translator_loop; } } } else { combinedResults.addAll( tmp ); } } -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira