Bug 190769 [Regression]The attached report pop up exception when preview
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/QueryResultSet.java
return null;
		}
		/**
		 * Returns the column alias at the specified index. An alias is given to
		 * a column as a programmatic convenience. A column can be referred
		 * using a name or an alias interchangeably.
		 * 
		 * @param index
		 *            The projected column index.
		 * @return The alias of the specified column. Null if none is defined.
		 * @throws BirtException
		 *             if given index is invalid.
		 */
		public String getColumnAlias( int index ) throws BirtException
		{
			return null;
		}
		/**
		 * Returns the data type of the column at the specified index.
		 * 
		 * @param index
		 *            The projected column index.
		 * @return The data type of the specified column, as an integer defined
		 *         in org.eclipse.birt.data.engine.api.DataType.
		 * @throws BirtException
		 *             if given index is invalid.
		 */
		public int getColumnType( int index ) throws BirtException
		{
			return 0;