Bug 141950 Selection of select value in data set filter is error
Details: Selection of select value in data set filter is error Step: 1.New a report design. 2.Create a sample datasource and dataset. 3.Switch to filter. 4.Select a value in expression. 5.Drop the list of the value1 and select <select value...> Actual result: No value is appear and pop up an error. It said that "An expression has not been set"
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
columns[n].setDataTypeName( metaData.getColumnTypeName( n + 1 ) );
			columns[n].setPosition( n + 1 );
			columns[n].setAlias( metaData.getColumnAlias( n + 1 ) );
			columns[n].setComputedColumn( metaData.isComputedColumn( n + 1 ) );
			String columnName = metaData.getColumnName( n + 1 );
			
			String uniqueColumnName = getUniqueName( orgColumnNameSet,
					uniqueColumnNameSet,
					columnName,
					n );
			
			columns[n].setDataSetColumnName( uniqueColumnName );
			uniqueColumnNameSet.add( uniqueColumnName );
			
			if ( !uniqueColumnName.equals( columnName ) )
				updateModelColumn( dataSet, columns[n] );
		}
		updateModel( dataSet, columns );
		htColumns.put( dataSet, columns );
	}
	
	/**
	 * 
	 * @param dataSetDesign
	 * @param rowsToReturn
	 * @return
	 */
	public final QueryDefinition getQueryDefinition(
			IBaseDataSetDesign dataSetDesign, int rowsToReturn )
	{