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... ... @@ -14,8 +14,10 @@
14 14  
15 15  The VTL language can be applied to SDMX artefacts by mapping the SDMX IM model artefacts to the model artefacts that VTL can manipulate{{footnote}}In this chapter, in order to distinguish VTL and SDMX model artefacts, the VTL ones are written in the Arial font while the SDMX ones in Courier New{{/footnote}}. Thus, the SDMX artefacts can be used in VTL as inputs and/or outputs of Transformations. It is important to be aware that the artefacts do not always have the same names in the SDMX and VTL IMs, nor do they always have the same meaning. The more evident example is given by the SDMX Dataset and the VTL "Data Set", which do not correspond one another: as a matter of fact, the VTL "Data Set" maps to the SDMX "Dataflow", while the SDMX "Dataset" has no explicit mapping to VTL (such an abstraction is not needed in the definition of VTL Transformations). A SDMX "Dataset", however, is an instance of a SDMX "Dataflow" and can be the artefact on which the VTL transformations are executed (i.e., the Transformations are defined on Dataflows and are applied to Dataflow instances that can be Datasets).
16 16  
17 -The VTL programs (Transformation Schemes) are represented in SDMX through the TransformationScheme maintainable class which is composed of Transformation (nameable artefact). Each Transformation assigns the outcome of the evaluation of a VTL expression to a result.
17 +The VTL programs (Transformation Schemes) are represented in SDMX through the TransformationScheme maintainable class which is composed of
18 18  
19 +Transformation (nameable artefact). Each Transformation assigns the outcome of the evaluation of a VTL expression to a result.
20 +
19 19  This section does not explain the VTL language or any of the content published in the VTL guides. Rather, this is a description of how the VTL can be used in the SDMX context and applied to SDMX artefacts.
20 20  
21 21  == 12.2 References to SDMX artefacts from VTL statements ==
... ... @@ -241,7 +241,7 @@
241 241  
242 242  AttributeRelationship is not specified (i.e. the DataAttribute does not depend on any DimensionComponent and therefore is at data set level), or if it refers to a set (or a group) of dimensions which does not include the MeasureDimension;
243 243  
244 -*
246 +*
245 245  ** Otherwise, if, according to the SDMX AttributeRelationship, the values of the DataAttribute depend on the MeasureDimension, the SDMX DataAttribute is mapped to one VTL Attribute for each possible Code of the SDMX MeasureDimension. By default, the names of the VTL Attributes are obtained by concatenating the name of the SDMX DataAttribute and the names of the correspondent Code of the MeasureDimension separated by underscore. For example, if the SDMX DataAttribute is named DA and the possible Codes of the SDMX MeasureDimension are named C1, C2, …, Cn, then the corresponding VTL Attributes will be named DA_C1, DA_C2, …, DA_Cn (if different names are desired, they can be achieved afterwards by renaming the Attributes through VTL operators).
246 246  ** Like in the Basic mapping, the resulting VTL Attributes are considered as dependent on all the VTL identifiers (i.e. "at data point / observation level"), because VTL does not have the SDMX notion of Attribute Relationship.
247 247  
... ... @@ -634,159 +634,189 @@
634 634  
635 635  The following table describes the default mapping for converting from the SDMX data types to the VTL basic scalar types.
636 636  
637 -(% style="width:823.294px" %)
638 -|(% style="width:509px" %)**SDMX data type (BasicComponentDataType)**|(% style="width:312px" %)**Default VTL basic scalar type**
639 -|(% style="width:509px" %)(((
639 +|(% style="width:501px" %)SDMX data type (BasicComponentDataType)|(% style="width:1437px" %)Default VTL basic scalar type
640 +|(% style="width:501px" %)(((
640 640  String
641 641  (string allowing any character)
642 -)))|(% style="width:312px" %)string
643 -|(% style="width:509px" %)(((
643 +)))|(% style="width:1437px" %)string
644 +|(% style="width:501px" %)(((
644 644  Alpha
645 645  (string which only allows A-z)
646 -)))|(% style="width:312px" %)string
647 -|(% style="width:509px" %)(((
647 +)))|(% style="width:1437px" %)string
648 +|(% style="width:501px" %)(((
648 648  AlphaNumeric
649 649  (string which only allows A-z and 0-9)
650 -)))|(% style="width:312px" %)string
651 -|(% style="width:509px" %)(((
651 +)))|(% style="width:1437px" %)string
652 +|(% style="width:501px" %)(((
652 652  Numeric
653 653  (string which only allows 0-9, but is not numeric so that is can having leading zeros)
654 -)))|(% style="width:312px" %)string
655 -|(% style="width:509px" %)(((
655 +)))|(% style="width:1437px" %)string
656 +|(% style="width:501px" %)(((
656 656  BigInteger
657 657  (corresponds to XML Schema xs:integer datatype; infinite set of integer values)
658 -)))|(% style="width:312px" %)integer
659 -|(% style="width:509px" %)(((
659 +)))|(% style="width:1437px" %)integer
660 +|(% style="width:501px" %)(((
660 660  Integer
661 661  (corresponds to XML Schema xs:int datatype; between -2147483648 and +2147483647 (inclusive))
662 -)))|(% style="width:312px" %)integer
663 -|(% style="width:509px" %)(((
663 +)))|(% style="width:1437px" %)integer
664 +|(% style="width:501px" %)(((
664 664  Long
665 -(corresponds to XML Schema xs:long datatype; between -9223372036854775808 and +9223372036854775807 (inclusive))
666 -)))|(% style="width:312px" %)integer
667 -|(% style="width:509px" %)(((
666 +(corresponds to XML Schema xs:long datatype; between -9223372036854775808 and
667 +
668 ++9223372036854775807 (inclusive))
669 +)))|(% style="width:1437px" %)integer
670 +|(% style="width:501px" %)(((
668 668  Short
669 669  (corresponds to XML Schema xs:short datatype; between -32768 and -32767 (inclusive))
670 -)))|(% style="width:312px" %)integer
671 -|(% style="width:509px" %)Decimal (corresponds to XML Schema xs:decimal datatype; subset of real numbers that can be represented as decimals)|(% style="width:312px" %)number
672 -|(% style="width:509px" %)(((
673 +)))|(% style="width:1437px" %)integer
674 +|(% style="width:501px" %)Decimal (corresponds to XML Schema xs:decimal datatype; subset of real numbers that can be represented as decimals)|(% style="width:1437px" %)number
675 +|(% style="width:501px" %)(((
673 673  Float
674 674  (corresponds to XML Schema xs:float datatype; patterned after the IEEE single-precision 32-bit floating point type)
675 -)))|(% style="width:312px" %)number
676 -|(% style="width:509px" %)(((
678 +)))|(% style="width:1437px" %)number
679 +|(% style="width:501px" %)(((
677 677  Double
678 678  (corresponds to XML Schema xs:double datatype; patterned after the IEEE double-precision 64-bit floating point type)
679 -)))|(% style="width:312px" %)number
680 -|(% style="width:509px" %)(((
682 +)))|(% style="width:1437px" %)number
683 +|(% style="width:501px" %)(((
681 681  Boolean
682 682  (corresponds to the XML Schema xs:boolean datatype; support the mathematical concept of binary-valued logic: {true, false})
683 -)))|(% style="width:312px" %)boolean
686 +)))|(% style="width:1437px" %)boolean
684 684  
685 -(% style="width:822.294px" %)
686 -|(% colspan="2" style="width:507px" %)(((
688 +| |(% colspan="2" %)(((
687 687  URI
690 +
688 688  (corresponds to the XML Schema xs:anyURI; absolute or relative Uniform Resource Identifier Reference)
689 -)))|(% colspan="1" style="width:311px" %)string
690 -|(% colspan="2" style="width:507px" %)(((
692 +)))|(% colspan="2" %)string
693 +| |(% colspan="2" %)(((
691 691  Count
695 +
692 692  (an integer following a sequential pattern, increasing by 1 for each occurrence)
693 -)))|(% colspan="1" style="width:311px" %)integer
694 -|(% colspan="2" style="width:507px" %)(((
697 +)))|(% colspan="2" %)integer
698 +| |(% colspan="2" %)(((
695 695  InclusiveValueRange
700 +
696 696  (decimal number within a closed interval, whose bounds are specified in the SDMX representation by the facets minValue and maxValue)
697 -)))|(% colspan="1" style="width:311px" %)number
698 -|(% colspan="2" style="width:507px" %)(((
702 +)))|(% colspan="2" %)number
703 +| |(% colspan="2" %)(((
699 699  ExclusiveValueRange
705 +
700 700  (decimal number within an open interval, whose bounds are specified in the SDMX representation by the facets minValue and maxValue)
701 -)))|(% colspan="1" style="width:311px" %)number
702 -|(% colspan="2" style="width:507px" %)(((
707 +)))|(% colspan="2" %)number
708 +| |(% colspan="2" %)(((
703 703  Incremental
710 +
704 704  (decimal number the increased by a specific interval (defined by the interval facet), which is typically enforced outside of the XML validation)
705 -)))|(% colspan="1" style="width:311px" %)number
706 -|(% colspan="2" style="width:507px" %)(((
712 +)))|(% colspan="2" %)number
713 +| |(% colspan="2" %)(((
707 707  ObservationalTimePeriod
715 +
708 708  (superset of StandardTimePeriod and TimeRange)
709 -)))|(% colspan="1" style="width:311px" %)time
710 -|(% colspan="2" style="width:507px" %)(((
717 +)))|(% colspan="2" %)time
718 +| |(% colspan="2" %)(((
711 711  StandardTimePeriod
712 -(superset of BasicTimePeriod and ReportingTimePeriod)
713 -)))|(% colspan="1" style="width:311px" %)time
714 -|(% colspan="2" style="width:507px" %)(((
720 +
721 +(superset of BasicTimePeriod and
722 +
723 +ReportingTimePeriod)
724 +)))|(% colspan="2" %)time
725 +| |(% colspan="2" %)(((
715 715  BasicTimePeriod
727 +
716 716  (superset of GregorianTimePeriod and DateTime)
717 -)))|(% colspan="1" style="width:311px" %)date
718 -|(% colspan="2" style="width:507px" %)(((
729 +)))|(% colspan="2" %)date
730 +| |(% colspan="2" %)(((
719 719  GregorianTimePeriod
732 +
720 720  (superset of GregorianYear, GregorianYearMonth, and GregorianDay)
721 -)))|(% colspan="1" style="width:311px" %)date
722 -|(% colspan="2" style="width:507px" %)GregorianYear (YYYY)|(% colspan="1" style="width:311px" %)date
723 -|(% colspan="2" style="width:507px" %)GregorianYearMonth / GregorianMonth (YYYY-MM)|(% colspan="1" style="width:311px" %)date
724 -|(% colspan="2" style="width:507px" %)GregorianDay (YYYY-MM-DD)|(% colspan="1" style="width:311px" %)date
725 -|(% colspan="2" style="width:507px" %)(((
734 +)))|(% colspan="2" %)date
735 +| |(% colspan="2" %)GregorianYear (YYYY)|(% colspan="2" %)date
736 +| |(% colspan="2" %)GregorianYearMonth / GregorianMonth (YYYY-MM)|(% colspan="2" %)date
737 +| |(% colspan="2" %)GregorianDay (YYYY-MM-DD)|(% colspan="2" %)date
738 +| |(% colspan="2" %)(((
726 726  ReportingTimePeriod
727 -(superset of RepostingYear, ReportingSemester, ReportingTrimester, ReportingQuarter, ReportingMonth, ReportingWeek, ReportingDay)
728 -)))|(% colspan="1" style="width:311px" %)time_period
729 -|(% colspan="2" style="width:507px" %)(((
740 +
741 +(superset of RepostingYear, ReportingSemester,
742 +
743 +ReportingTrimester, ReportingQuarter,
744 +
745 +ReportingMonth, ReportingWeek, ReportingDay)
746 +)))|(% colspan="2" %)time_period
747 +| |(% colspan="2" %)(((
730 730  ReportingYear
749 +
731 731  (YYYY-A1 – 1 year period)
732 -)))|(% colspan="1" style="width:311px" %)time_period
733 -|(% colspan="2" style="width:507px" %)(((
751 +)))|(% colspan="2" %)time_period
752 +| |(% colspan="2" %)(((
734 734  ReportingSemester
754 +
735 735  (YYYY-Ss – 6 month period)
736 -)))|(% colspan="1" style="width:311px" %)time_period
737 -|(% colspan="2" style="width:507px" %)(((
756 +)))|(% colspan="2" %)time_period
757 +| |(% colspan="2" %)(((
738 738  ReportingTrimester
759 +
739 739  (YYYY-Tt – 4 month period)
740 -)))|(% colspan="1" style="width:311px" %)time_period
741 -|(% colspan="2" style="width:507px" %)(((
761 +)))|(% colspan="2" %)time_period
762 +| |(% colspan="2" %)(((
742 742  ReportingQuarter
764 +
743 743  (YYYY-Qq – 3 month period)
744 -)))|(% colspan="1" style="width:311px" %)time_period
745 -|(% colspan="2" style="width:507px" %)(((
766 +)))|(% colspan="2" %)time_period
767 +| |(% colspan="2" %)(((
746 746  ReportingMonth
769 +
747 747  (YYYY-Mmm – 1 month period)
748 -)))|(% colspan="1" style="width:311px" %)time_period
749 -|(% colspan="2" style="width:507px" %)ReportingWeek|(% colspan="1" style="width:311px" %)time_period
750 -|(% colspan="1" style="width:507px" %)(YYYY-Www – 7 day period; following ISO 8601 definition of a week in a year)|(% colspan="2" style="width:312px" %)
751 -|(% colspan="1" style="width:507px" %)(((
771 +)))|(% colspan="2" %)time_period
772 +| |(% colspan="2" %)ReportingWeek|(% colspan="2" %)time_period
773 +| |(% colspan="2" %) |(% colspan="2" %)
774 +| |(% colspan="2" %) |(% colspan="2" %)
775 +|(% colspan="2" %)(YYYY-Www – 7 day period; following ISO 8601 definition of a week in a year)|(% colspan="2" %) |
776 +|(% colspan="2" %)(((
752 752  ReportingDay
778 +
753 753  (YYYY-Dddd – 1 day period)
754 -)))|(% colspan="2" style="width:312px" %)time_period
755 -|(% colspan="1" style="width:507px" %)(((
780 +)))|(% colspan="2" %)time_period|
781 +|(% colspan="2" %)(((
756 756  DateTime
783 +
757 757  (YYYY-MM-DDThh:mm:ss)
758 -)))|(% colspan="2" style="width:312px" %)date
759 -|(% colspan="1" style="width:507px" %)(((
785 +)))|(% colspan="2" %)date|
786 +|(% colspan="2" %)(((
760 760  TimeRange
788 +
761 761  (YYYY-MM-DD(Thh:mm:ss)?/<duration>)
762 -)))|(% colspan="2" style="width:312px" %)time
763 -|(% colspan="1" style="width:507px" %)(((
790 +)))|(% colspan="2" %)time|
791 +|(% colspan="2" %)(((
764 764  Month
793 +
765 765  (~-~-MM; speicifies a month independent of a year; e.g. February is black history month in the United States)
766 -)))|(% colspan="2" style="width:312px" %)string
767 -|(% colspan="1" style="width:507px" %)(((
795 +)))|(% colspan="2" %)string|
796 +|(% colspan="2" %)(((
768 768  MonthDay
798 +
769 769  (~-~-MM-DD; specifies a day within a month independent of a year; e.g. Christmas is December 25^^th^^; used to specify reporting year start day)
770 -)))|(% colspan="2" style="width:312px" %)string
771 -|(% colspan="1" style="width:507px" %)(((
800 +)))|(% colspan="2" %)string|
801 +|(% colspan="2" %)(((
772 772  Day
803 +
773 773  (~-~--DD; specifies a day independent of a month or year; e.g. the 15^^th^^ is payday)
774 -)))|(% colspan="2" style="width:312px" %)string
775 -|(% colspan="1" style="width:507px" %)(((
805 +)))|(% colspan="2" %)string|
806 +|(% colspan="2" %)(((
776 776  Time
808 +
777 777  (hh:mm:ss; time independent of a date; e.g. coffee break is at 10:00 AM)
778 -)))|(% colspan="2" style="width:312px" %)string
779 -|(% colspan="1" style="width:507px" %)(((
810 +)))|(% colspan="2" %)string|
811 +|(% colspan="2" %)(((
780 780  Duration
813 +
781 781  (corresponds to XML Schema xs:duration datatype)
782 -)))|(% colspan="2" style="width:312px" %)duration
783 -|(% colspan="1" style="width:507px" %)XHTML|(% colspan="2" style="width:312px" %)Metadata type – not applicable
784 -|(% colspan="1" style="width:507px" %)KeyValues|(% colspan="2" style="width:312px" %)Metadata type – not applicable
785 -|(% colspan="1" style="width:507px" %)IdentifiableReference|(% colspan="2" style="width:312px" %)Metadata type – not applicable
786 -|(% colspan="1" style="width:507px" %)DataSetReference|(% colspan="2" style="width:312px" %)Metadata type – not applicable
815 +)))|(% colspan="2" %)duration|
816 +|(% colspan="2" %)XHTML|(% colspan="2" %)Metadata type – not applicable|
817 +|(% colspan="2" %)KeyValues|(% colspan="2" %)Metadata type – not applicable|
818 +|(% colspan="2" %)IdentifiableReference|(% colspan="2" %)Metadata type – not applicable|
819 +|(% colspan="2" %)DataSetReference|(% colspan="2" %)Metadata type – not applicable|
787 787  
788 -(% class="wikigeneratedid" id="HFigure142013MappingsfromSDMXdatatypestoVTLBasicScalarTypes" %)
789 -**Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types**
821 +==== Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types ====
790 790  
791 791  When VTL takes in input SDMX artefacts, it is assumed that a type conversion according to the table above always happens. In case a different VTL basic scalar type is desired, it can be achieved in the VTL program taking in input the default VTL basic scalar type above and applying to it the VTL type conversion features (see the implicit and explicit type conversion and the "cast" operator in the VTL Reference Manual).
792 792  
... ... @@ -794,32 +794,39 @@
794 794  
795 795  The following table describes the default conversion from the VTL basic scalar types to the SDMX data types .
796 796  
797 -(% style="width:1073.29px" %)
798 -|(% style="width:207px" %)(((
799 -**VTL basic scalar type**
800 -)))|(% style="width:462px" %)(((
801 -**Default SDMX data type (BasicComponentDataType)**
802 -)))|(% style="width:402px" %)**Default output format**
803 -|(% style="width:207px" %)String|(% style="width:462px" %)String|(% style="width:402px" %)Like XML (xs:string)
804 -|(% style="width:207px" %)Number|(% style="width:462px" %)Float|(% style="width:402px" %)Like XML (xs:float)
805 -|(% style="width:207px" %)Integer|(% style="width:462px" %)Integer|(% style="width:402px" %)Like XML (xs:int)
806 -|(% style="width:207px" %)Date|(% style="width:462px" %)DateTime|(% style="width:402px" %)YYYY-MM-DDT00:00:00Z
807 -|(% style="width:207px" %)Time|(% style="width:462px" %)StandardTimePeriod|(% style="width:402px" %)<date>/<date> (as defined above)
808 -|(% style="width:207px" %)time_period|(% style="width:462px" %)(((
829 +|(((
830 +VTL basic
831 +
832 +scalar type
833 +)))|(((
834 +Default SDMX data type
835 +
836 +(BasicComponentDataType
837 +
838 +)
839 +)))|Default output format
840 +|String|String|Like XML (xs:string)
841 +|Number|Float|Like XML (xs:float)
842 +|Integer|Integer|Like XML (xs:int)
843 +|Date|DateTime|YYYY-MM-DDT00:00:00Z
844 +|Time|StandardTimePeriod|<date>/<date> (as defined above)
845 +|time_period|(((
809 809  ReportingTimePeriod
847 +
810 810  (StandardReportingPeriod)
811 -)))|(% style="width:402px" %)(((
849 +)))|(((
812 812  YYYY-Pppp
851 +
813 813  (according to SDMX )
814 814  )))
815 -|(% style="width:207px" %)Duration|(% style="width:462px" %)Duration|(% style="width:402px" %)(((
854 +|Duration|Duration|(((
816 816  Like XML (xs:duration)
856 +
817 817  PnYnMnDTnHnMnS
818 818  )))
819 -|(% style="width:207px" %)Boolean|(% style="width:462px" %)Boolean|(% style="width:402px" %)Like XML (xs:boolean) with the values "true" or "false"
859 +|Boolean|Boolean|Like XML (xs:boolean) with the values "true" or "false"
820 820  
821 -(% class="wikigeneratedid" id="HFigure142013MappingsfromSDMXdatatypestoVTLBasicScalarTypes-1" %)
822 -**Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types**
861 +==== Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types ====
823 823  
824 824  In case a different default conversion is desired, it can be achieved through the CustomTypeScheme and CustomType artefacts (see also the section Transformations and Expressions of the SDMX information model).
825 825  
... ... @@ -873,7 +873,7 @@
873 873  |N|fixed number of digits used in the preceding textual representation of the month or the day
874 874  | |
875 875  
876 -The default conversion, either standard or customized, can be used to deduce automatically the representation of the components of the result of a VTL Transformation. In alternative, the representation of the resulting SDMX Dataflow can be given explicitly by providing its DataStructureDefinition. In other words, the representation specified in the DSD, if available, overrides any default conversion{{footnote}}The representation given in the DSD should obviously be compatible with the VTL data type.{{/footnote}}.
915 +The default conversion, either standard or customized, can be used to deduce automatically the representation of the components of the result of a VTL Transformation. In alternative, the representation of the resulting SDMX Dataflow can be given explicitly by providing its DataStructureDefinition. In other words, the representation specified in the DSD, if available, overrides any default conversion^^[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^42^^>>path:#sdfootnote42sym||name="sdfootnote42anc"]](%%)^^.
877 877  
878 878  === 12.4.5 Null Values ===
879 879  
... ... @@ -891,8 +891,10 @@
891 891  
892 892  A different format can be specified in the attribute "vtlLiteralFormat" of the CustomType artefact (see also the section Transformations and Expressions of the SDMX information model).
893 893  
894 -Like in the case of the conversion of NULLs described in the previous paragraph, the overriding assumption is applied, for a certain VTL basic scalar type, if a value is found for the vtlLiteralFormat attribute of the CustomType of such VTL basic scalar type. The overriding assumption is applied for all the literals of a related VTL TransformationScheme.
933 +Like in the case of the conversion of NULLs described in the previous paragraph, the overriding assumption is applied, for a certain VTL basic scalar type, if a value is found for the vtlLiteralFormat attribute of the CustomType of such VTL basic scalar type. The overriding assumption is applied for all the literals of a related VTL
895 895  
935 +TransformationScheme.
936 +
896 896  In case a literal is operand of a VTL Cast operation, the format specified in the Cast overrides all the possible otherwise specified formats.
897 897  
898 898  {{putFootnotes/}}