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
assert false;
				}
			}
		}
		/**
		 * visit content of a row
		 */
		protected void handleRow( RowDesign row, Object value )
		{
			
			if ( row.getVisibility( ) != null )
			{
				for ( int i = 0; i < row.getVisibility( ).count( ); i++ )
					addExpression( row.getVisibility( ).getRule( i )
							.getExpression( ) );
			}
			addExpression(row.getTOC());
			addExpression( row.getBookmark( ) );
			for ( int i = 0; i < row.getCellCount( ); i++ )
			{
				CellDesign cell = row.getCell( i );
				if ( cell != null )
				{
					handleCell( cell, value );
				}
			}
		}
		/**
		 * handles a cell in a row
		 */