Bug 213907 Provide a copy constructor for SubqueryDefinition.
Engine need a copy constructor to generate a SubqueryDefinition from an ISubqueryDefinition and change the name of the query.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedQuery.java
throw new DataException( ResourceConstants.GROUP_NOT_EXIST,
								new Object[]{
								groupName, key
								} );
					}
				}
			}
			mappingParentColumnBinding( );
			
			for ( int i = 0; i <= groups.size( ); i++ )
			{
				prepareGroup( baseQueryDefn, i, cx );
			}
		}
		finally
		{			
		    Context.exit();
		}
	}
	
	/**
	 * @throws DataException 
	 * 
	 */
	private void mappingParentColumnBinding( ) throws DataException
	{
		IBaseQueryDefinition queryDef =  baseQueryDefn;
		while ( queryDef instanceof ISubqueryDefinition )
		{
			queryDef = queryDef.getParentQuery();