Bug 122854 There is redundant columns in "available columns" list in "export data" dialog.
Description: There is redundant columns in "available columns" list in "export data" dialog. Steps to reproduce: 1. Preview attached design in web viewer. 2. Select the table and click on "export" button. 3. There is a "detail" column name in "available columns" list which is not data set column.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/ReportQueryBuilder.java
for ( int i = 0; i < map.getRuleCount( ); i++ )
				{
					MapRuleDesign rule = map.getRule( i );
					if ( rule != null )
						addExpression( rule.getConditionExpr( ) );
				}
			}
		}
		/**
		 * handle highlight expressions
		 */
		protected void handleHighlightExpressions( HighlightDesign highlight )
		{
			if ( highlight != null )
			{
				for ( int i = 0; i < highlight.getRuleCount( ); i++ )
				{
					HighlightRuleDesign rule = highlight.getRule( i );
					if ( rule != null )
						addExpression( rule.getConditionExpr( ) );
				}
			}
		}
		/**
		 * handles action expressions, i.e, book-mark and hyper-link
		 * expressions.
		 */
		protected void handleAction( ActionDesign action )
		{
			if ( action != null )