Bug 131011 Support running query based on report document data
Data Engine should support running a query based on data set and expression data stored in a report document. This bugzilla entry serves as a repository for design docs and notes related to this feature.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/group/GroupBy.java
case GroupSpec.NO_INTERVAL :
				groupBy = new GroupByDistinctValue( );
				break;
			case GroupSpec.NUMERIC_INTERVAL :
				if ( isNumber( columnType ) )
					groupBy = new GroupByNumberRange( groupDefn );
				else
					throw new DataException( ResourceConstants.BAD_GROUP_INTERVAL_TYPE,
							new Object[]{
									"numeric", columnType.getName( )
							} );
				break;
			case GroupSpec.STRING_PREFIX_INTERVAL :
				if ( isString( columnType ) )
					groupBy = new GroupByStringRange( groupDefn );
				else
					throw new DataException( ResourceConstants.BAD_GROUP_INTERVAL_TYPE,
							new Object[]{
									"string prefix", columnType.getName( )
							} );
				break;
			default :
				if ( isDate( columnType ) )
					groupBy = new GroupByDateRange( groupDefn );
				else
					throw new DataException( ResourceConstants.BAD_GROUP_INTERVAL_TYPE,
							new Object[]{
									"date", columnType.getName( )
							} );
		}