Changes for page 12 Validation and Transformation Language (VTL)
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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 == ... ... @@ -26,8 +26,10 @@ 26 26 27 27 The alias of an SDMX artefact can be its URN (Universal Resource Name), an abbreviation of its URN or another user-defined name. 28 28 29 -In any case, the aliases used in the VTL Transformations have to be mapped to the SDMX artefacts through the VtlMappingScheme and VtlMapping classes (see the section of the SDMX IM relevant to the VTL). A VtlMapping allows specifying the aliases to be used in the VTL Transformations, Rulesets{{footnote}}See also the section "VTL-DL Rulesets" in the VTL Reference Manual.{{/footnote}} or User Defined Operators{{footnote}}The VTLMappings are used also for User Defined Operators (UDO). Although UDOs are envisaged to be defined on generic operands, so that the specific artefacts to be manipulated are passed as parameters at their invocation, it is also possible that an UDO invokes directly some specific SDMX artefacts. These SDMX artefacts have to be mapped to the corresponding aliases used in the definition of the UDO through the VtlMappingScheme and VtlMapping classes as well.{{/footnote}} to reference SDMX artefacts. A VtlMappingScheme is a container for zero or more VtlMapping.31 +In any case, the aliases used in the VTL Transformations have to be mapped to the 30 30 33 +SDMX artefacts through the VtlMappingScheme and VtlMapping classes (see the section of the SDMX IM relevant to the VTL). A VtlMapping allows specifying the aliases to be used in the VTL Transformations, Rulesets{{footnote}}See also the section "VTL-DL Rulesets" in the VTL Reference Manual.{{/footnote}} or User Defined Operators{{footnote}}The VTLMappings are used also for User Defined Operators (UDO). Although UDOs are envisaged to be defined on generic operands, so that the specific artefacts to be manipulated are passed as parameters at their invocation, it is also possible that an UDO invokes directly some specific SDMX artefacts. These SDMX artefacts have to be mapped to the corresponding aliases used in the definition of the UDO through the VtlMappingScheme and VtlMapping classes as well.{{/footnote}} to reference SDMX artefacts. A VtlMappingScheme is a container for zero or more VtlMapping. 34 + 31 31 The correspondence between an alias and a SDMX artefact must be one-to-one, meaning that a generic alias identifies one and just one SDMX artefact while a SDMX artefact is identified by one and just one alias. In other words, within a VtlMappingScheme an artefact can have just one alias and different artefacts cannot have the same alias. 32 32 33 33 The references through the URN and the abbreviated URN are described in the following paragraphs. ... ... @@ -198,7 +198,7 @@ 198 198 199 199 === 12.3.3 Mapping from SDMX to VTL data structures === 200 200 201 - ====12.3.3.1 Basic Mapping====205 +**12.3.3.1 Basic Mapping** 202 202 203 203 The main mapping method from SDMX to VTL is called **Basic **mapping. This is considered as the default mapping method and is applied unless a different method is specified through the VtlMappingScheme and VtlDataflowMapping classes. When transforming **from SDMX to VTL**, this method consists in leaving the components unchanged and maintaining their names and roles, according to the following table: 204 204 ... ... @@ -228,11 +228,18 @@ 228 228 The SDMX structures that contain a MeasureDimension are mapped as described below (this mapping is equivalent to a pivoting operation): 229 229 230 230 * A SDMX simple dimension becomes a VTL (simple) identifier and a SDMX TimeDimension becomes a VTL (time) identifier; 231 -* Each possible Code Cj of the SDMX MeasureDimension is mapped to a VTL Measure, having the same name as the SDMX Code (i.e. Cj); the VTL Measure Cj is a new VTL component even if the SDMX data structure has not such a Component; 235 +* Each possible Code Cj of the SDMX MeasureDimension is mapped to a VTL Measure, having the same name as the SDMX Code (i.e. Cj); the VTL Measure Cj is a new VTL component even if the SDMX data structure has not such a 236 + 237 +Component; 238 + 232 232 * The SDMX MeasureDimension is not mapped to VTL (it disappears in the VTL Data Structure); 233 233 * The SDMX Measure is not mapped to VTL as well (it disappears in the VTL Data Structure); 234 234 * An SDMX DataAttribute is mapped in different ways according to its AttributeRelationship: 235 -** If, according to the SDMX AttributeRelationship, the values of the DataAttribute do not depend on the values of the MeasureDimension, the SDMX DataAttribute becomes a VTL Attribute having the same name. This happens if the 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; 242 +** If, according to the SDMX AttributeRelationship, the values of the DataAttribute do not depend on the values of the MeasureDimension, the SDMX DataAttribute becomes a VTL Attribute having the same name. This happens if the 243 + 244 +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; 245 + 246 +* 236 236 ** 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). 237 237 ** 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. 238 238 ... ... @@ -255,7 +255,10 @@ 255 255 At observation / data point level, calling Cj (j=1, … n) the j^^th^^ Code of the MeasureDimension: 256 256 257 257 * The set of SDMX observations having the same values for all the Dimensions except than the MeasureDimension become one multi-measure VTL Data Point, having one Measure for each Code Cj of the SDMX MeasureDimension; 258 -* The values of the SDMX simple Dimensions, TimeDimension and DataAttributes not depending on the MeasureDimension (these components by definition have always the same values for all the observations of the set above) become the values of the corresponding VTL (simple) Identifiers, (time) Identifier and Attributes. 269 +* The values of the SDMX simple Dimensions, TimeDimension and DataAttributes not depending on the MeasureDimension (these components by definition have always the same values for all the observations of the set above) become the values of the corresponding VTL (simple) 270 + 271 +Identifiers, (time) Identifier and Attributes. 272 + 259 259 * The value of the Measure of the SDMX observation belonging to the set above and having MeasureDimension=Cj becomes the value of the VTL Measure Cj 260 260 * For the SDMX DataAttributes depending on the MeasureDimension, the value of the DataAttribute DA of the SDMX observation belonging to the set above and having MeasureDimension=Cj becomes the value of the VTL Attribute DA_Cj 261 261 ... ... @@ -348,7 +348,7 @@ 348 348 The mapping table is the following: 349 349 350 350 (% style="width:689.294px" %) 351 -|(% style="width:344px" %) **VTL**|(% style="width:341px" %)**SDMX**365 +|(% style="width:344px" %)VTL|(% style="width:341px" %)SDMX 352 352 |(% style="width:344px" %)(Simple) Identifier|(% style="width:341px" %)Dimension 353 353 |(% style="width:344px" %)(Time) Identifier|(% style="width:341px" %)TimeDimension 354 354 |(% style="width:344px" %)Some Measures|(% style="width:341px" %)Measure ... ... @@ -408,14 +408,26 @@ 408 408 409 409 SDMX Dataflow having INDICATOR=//INDICATORvalue //and COUNTRY=// COUNTRYvalue//. For example, the VTL dataset ‘DF1(1.0.0)/POPULATION.USA’ would contain all the observations of DF1(1.0.0) having INDICATOR = POPULATION and COUNTRY = USA. 410 410 411 -In order to obtain the data structure of these VTL Data Sets from the SDMX one, it is assumed that the SDMX DimensionComponents on which the mapping is based are dropped, i.e. not maintained in the VTL data structure; this is possible because their values are fixed for each one of the invoked VTL Data Sets{{footnote}}If these DimensionComponents would not be dropped, the various VTL Data Sets resulting from this kind of mapping would have non-matching values for the Identifiers corresponding to the mapping Dimensions (e.g. POPULATION and COUNTRY). As a consequence, taking into account that the typical binary VTL operations at dataset level (+, -, *, / and so on) are executed on the observations having matching values for the identifiers, it would not be possible to compose the resulting VTL datasets one another (e.g. it would not be possible to calculate the population ratio between USA and CANADA).{{/footnote}}. After that, the mapping method from SDMX to VTL specified for the Dataflow DF1(1.0.0) is applied (i.e. basic, pivot …).425 +In order to obtain the data structure of these VTL Data Sets from the SDMX one, it is assumed that the SDMX DimensionComponents on which the mapping is based are dropped, i.e. not maintained in the VTL data structure; this is possible because their values are fixed for each one of the invoked VTL Data Sets{{footnote}}If these DimensionComponents would not be dropped, the various VTL Data Sets resulting from this kind of mapping would have non-matching values for the Identifiers corresponding to the mapping Dimensions (e.g. POPULATION and COUNTRY). As a consequence, taking into account that the typical binary VTL operations at dataset level (+, -, *, / and so on) are executed on the observations having matching values for the identifiers, it would not be possible to compose the resulting VTL datasets one another (e.g. it would not be possible to calculate the population ratio between USA and CANADA).{{/footnote}}. After that, the mapping method from SDMX to VTL specified for the Dataflow DF1(1.0.0) is applied (i.e. 412 412 413 - In the example above, forall the datasets of the kind ‘DF1(1.0.0)///INDICATORvalue//.//COUNTRYvalue//’,the dimensions INDICATOR and COUNTRY would be dropped so that the data structure of all the resulting VTL Data Sets would havetheidentifier TIME_PERIOD only.427 +basic, pivot …). 414 414 429 +In the example above, for all the datasets of the kind 430 + 431 +‘DF1(1.0.0)///INDICATORvalue//.//COUNTRYvalue//’, the dimensions INDICATOR and COUNTRY would be dropped so that the data structure of all the resulting VTL Data Sets would have the identifier TIME_PERIOD only. 432 + 415 415 It should be noted that the desired VTL Data Sets (i.e. of the kind ‘DF1(1.0.0)/// INDICATORvalue//.//COUNTRYvalue//’) can be obtained also by applying the VTL operator “**sub**” (subspace) to the Dataflow DF1(1.0.0), like in the following VTL expression: 416 416 417 - [[image:1747388275998-621.png]]435 +‘DF1(1.0.0)/POPULATION.USA’ := 418 418 437 +DF1(1.0.0) [ sub INDICATOR=“POPULATION”, COUNTRY=“USA” ]; 438 + 439 +‘DF1(1.0.0)/POPULATION.CANADA’ := 440 + 441 +DF1(1.0.0) [ sub INDICATOR=“POPULATION”, COUNTRY=“CANADA” ]; 442 + 443 +… … … 444 + 419 419 In fact the VTL operator “sub” has exactly the same behaviour. Therefore, mapping different parts of a SDMX Dataflow to different VTL Data Sets in the direction from SDMX to VTL through the ordered concatenation notation is equivalent to a proper use of the operator “**sub**” on such a Dataflow.{{footnote}}In case the ordered concatenation notation is used, the VTL Transformation described above, e.g. ‘DF1(1.0)/POPULATION.USA’ := DF1(1.0) [ sub INDICATOR=“POPULATION”, COUNTRY=“USA”], is implicitly executed. In order to test the overall compliance of the VTL program to the VTL consistency rules, it has to be considered as part of the VTL program even if it is not explicitly coded.{{/footnote}} 420 420 421 421 In the direction from SDMX to VTL it is allowed to omit the value of one or more ... ... @@ -426,8 +426,10 @@ 426 426 427 427 This is equivalent to the application of the VTL “sub” operator only to the identifier //INDICATOR//: 428 428 429 - [[image:1747388244829-693.png]]455 +‘DF1(1.0.0)/POPULATION.’ := 430 430 457 +DF1(1.0.0) [ sub INDICATOR=“POPULATION” ]; 458 + 431 431 Therefore the VTL Data Set ‘DF1(1.0.0)/POPULATION.’ would have the identifiers COUNTRY and TIME_PERIOD. 432 432 433 433 Heterogeneous invocations of the same Dataflow are allowed, i.e. omitting different ... ... @@ -453,18 +453,54 @@ 453 453 454 454 Some examples follow, for some specific values of INDICATOR and COUNTRY: 455 455 456 - [[image:1747388222879-916.png]]484 +‘DF2(1.0.0)/GDPPERCAPITA.USA’ <- expression11; ‘DF2(1.0.0)/GDPPERCAPITA.CANADA’ <- expression12; 457 457 458 - [[image:1747388206717-256.png]]486 +… … … 459 459 488 +‘DF2(1.0.0)/POPGROWTH.USA’ <- expression21; 489 + 490 +‘DF2(1.0.0)/POPGROWTH.CANADA’ <- expression22; 491 + 492 +… … … 493 + 460 460 As said, it is assumed that these VTL derived Data Sets have the TIME_PERIOD as the only identifier. In the mapping from VTL to SMDX, the Dimensions INDICATOR and COUNTRY are added to the VTL data structure on order to obtain the SDMX one, with the following values respectively: 461 461 462 - [[image:1747388148322-387.png]]496 +VTL dataset INDICATOR value COUNTRY value 463 463 498 +‘DF2(1.0.0)/GDPPERCAPITA.USA’ GDPPERCAPITA USA 499 + 500 +‘DF2(1.0.0)/GDPPERCAPITA.CANADA’ GDPPERCAPITA CANADA … … … 501 + 502 +‘DF2(1.0.0)/POPGROWTH.USA’ POPGROWTH USA 503 + 504 +‘DF2(1.0.0)/POPGROWTH.CANADA’ POPGROWTH CANADA 505 + 506 +… … … 507 + 464 464 It should be noted that the application of this many-to-one mapping from VTL to SDMX is equivalent to an appropriate sequence of VTL Transformations. These use the VTL operator “calc” to add the proper VTL identifiers (in the example, INDICATOR and COUNTRY) and to assign to them the proper values and the operator “union” in order to obtain the final VTL dataset (in the example DF2(1.0.0)), that can be mapped oneto-one to the homonymous SDMX Dataflow. Following the same example, these VTL Transformations would be: 465 465 466 - [[image:1747388179021-814.png]]510 +DF2bis_GDPPERCAPITA_USA := ‘DF2(1.0.0)/GDPPERCAPITA.USA’ [calc identifier INDICATOR := ”GDPPERCAPITA”, identifier COUNTRY := ”USA”]; 467 467 512 +DF2bis_GDPPERCAPITA_CANADA := ‘DF2(1.0.0)/GDPPERCAPITA.CANADA’ [calc identifier INDICATOR:=”GDPPERCAPITA”, identifier COUNTRY:=”CANADA”]; … … … 513 + 514 +DF2bis_POPGROWTH_USA := ‘DF2(1.0.0)/POPGROWTH.USA’ 515 + 516 +[calc identifier INDICATOR := ”POPGROWTH”, identifier COUNTRY := ”USA”]; 517 + 518 +DF2bis_POPGROWTH_CANADA’ := ‘DF2(1.0.0)/POPGROWTH.CANADA’ [calc identifier INDICATOR := ”POPGROWTH”, identifier COUNTRY := ”CANADA”]; … … … 519 + 520 +DF2(1.0) <- UNION (DF2bis_GDPPERCAPITA_USA’, 521 + 522 +DF2bis_GDPPERCAPITA_CANADA’, 523 + 524 +… , 525 + 526 +DF2bis_POPGROWTH_USA’, 527 + 528 +DF2bis_POPGROWTH_CANADA’ 529 + 530 +…); 531 + 468 468 In other words, starting from the datasets explicitly calculated through VTL (in the example ‘DF2(1.0)/GDPPERCAPITA.USA’ and so on), the first step consists in calculating other (non-persistent) VTL datasets (in the example 469 469 470 470 DF2bis_GDPPERCAPITA_USA and so on) by adding the identifiers INDICATOR and COUNTRY with the desired values (//INDICATORvalue// and //COUNTRYvalue)//. Finally, all these non-persistent Data Sets are united and give the final result DF2(1.0){{footnote}}The result is persistent in this example but it can be also non persistent if needed.{{/footnote}}, which can be mapped one-to-one to the homonymous SDMX Dataflow having the dimension components TIME_PERIOD, INDICATOR and COUNTRY. ... ... @@ -478,43 +478,50 @@ 478 478 With reference to the VTL “model for Variables and Value domains”, the following additional mappings have to be considered: 479 479 480 480 (% style="width:1170.29px" %) 481 -| (% style="width:392px" %)**VTL**|(% style="width:776px" %)**SDMX**482 -| (% style="width:392px" %)**Data Set Component**|(% style="width:776px" %)Although this abstraction exists in SDMX, it does not have an explicit definition and correspond to a Component (either a DimensionComponent or a Measure or a DataAttribute) belonging to one specific Dataflow{{footnote}}Through SDMX Constraints, it is possible to specify the values that a Component of a Dataflow can assume.{{/footnote}}483 -| (% style="width:392px" %)**Represented Variable**|(% style="width:776px" %)(((545 +|**VTL**|(% style="width:754px" %)**SDMX** 546 +|**Data Set Component**|(% style="width:754px" %)Although this abstraction exists in SDMX, it does not have an explicit definition and correspond to a Component (either a DimensionComponent or a Measure or a DataAttribute) belonging to one specific Dataflow{{footnote}}Through SDMX Constraints, it is possible to specify the values that a Component of a Dataflow can assume.{{/footnote}} 547 +|**Represented Variable**|(% style="width:754px" %)((( 484 484 **Concept** with a definite 485 485 486 486 Representation 487 487 ))) 488 -|(% style="width:392px" %)**Value Domain**|(% style="width:776px" %)((( 489 -**Representation** (see the Structure Pattern in the Base Package) 552 +|**Value Domain**|(% style="width:754px" %)((( 553 +**Representation** (see the Structure 554 + 555 +Pattern in the Base Package) 490 490 ))) 491 -| (% style="width:392px" %)**Enumerated Value Domain / Code List**|(% style="width:776px" %)**Codelist**492 -| (% style="width:392px" %)**Code**|(% style="width:776px" %)(((557 +|**Enumerated Value Domain / Code List**|(% style="width:754px" %)**Codelist** 558 +|**Code**|(% style="width:754px" %)((( 493 493 **Code** (for enumerated 494 494 495 495 DimensionComponent, Measure, DataAttribute) 496 496 ))) 497 -|(% style="width:392px" %)**Described Value Domain**|(% style="width:776px" %)((( 498 -non-enumerated** Representation **(having Facets / ExtendedFacets, see the Structure Pattern in the Base Package) 563 +|**Described Value Domain**|(% style="width:754px" %)((( 564 +non-enumerated** Representation** 565 + 566 +(having Facets / ExtendedFacets, see the Structure Pattern in the Base Package) 499 499 ))) 500 -|(% style="width:392px" %)**Value**|(% style="width:776px" %)Although this abstraction exists in SDMX, it does not have an explicit definition and correspond to a **Code** of a Codelist (for enumerated Representations) or to a valid **value **(for non-enumerated** **Representations) 501 -|(% style="width:392px" %)**Value Domain Subset / Set**|(% style="width:776px" %)This abstraction does not exist in SDMX 502 -|(% style="width:392px" %)**Enumerated Value Domain Subset / Enumerated Set**|(% style="width:776px" %)This abstraction does not exist in SDMX 503 -|(% style="width:392px" %)**Described Value Domain Subset / Described Set**|(% style="width:776px" %)This abstraction does not exist in SDMX 504 -|(% style="width:392px" %)**Set list**|(% style="width:776px" %)This abstraction does not exist in SDMX 568 +|**Value**|(% style="width:754px" %)Although this abstraction exists in SDMX, it does not have an explicit definition and correspond to a **Code** of a Codelist (for enumerated Representations) or 569 +| |(% style="width:754px" %)((( 570 +to a valid **value **(for non-enumerated** **Representations) 571 +))) 572 +|**Value Domain Subset / Set**|(% style="width:754px" %)This abstraction does not exist in SDMX 573 +|**Enumerated Value Domain Subset / Enumerated Set**|(% style="width:754px" %)This abstraction does not exist in SDMX 574 +|**Described Value Domain Subset / Described Set**|(% style="width:754px" %)This abstraction does not exist in SDMX 575 +|**Set list**|(% style="width:754px" %)This abstraction does not exist in SDMX 505 505 506 506 The main difference between VTL and SDMX relies on the fact that the VTL artefacts for defining subsets of Value Domains do not exist in SDMX, therefore the VTL features for referring to predefined subsets are not available in SDMX. These artefacts are the Value Domain Subset (or Set), either enumerated or described, the Set List (list of values belonging to enumerated subsets) and the Data Set Component (aimed at defining the set of values that the Component of a Data Set can take, possibly a subset of the codes of Value Domain). 507 507 508 -Another difference consists in the fact that all Value Domains are considered as identifiable objects in VTL either if enumerated or not, while in SDMX the Codelist (corresponding to a VTL enumerated Value Domain) is identifiable, while the SDMX non-enumerated Representation (corresponding to a VTL non-enumerated Value Domain) is not identifiable. As a consequence, the definition of the VTL Rulesets, which in VTL can refer either to enumerated or non-enumerated value domains, in SDMX can refer only to enumerated Value Domains (i.e. to SDMX Codelists). As for the mapping between VTL variables and SDMX Concepts, it should be noted that these artefacts do not coincide perfectly. In fact, the VTL variables are represented variables, defined always on the same Value Domain (“Representation” in SDMX) independently of the data set / data structure in which they appear {{footnote}}By usingrepresentedvariables,VTL can assume thatdatastructureshavingthesamevariablesasidentifierscanbecomposedone anotherbecause thecorrespondentvaluescanmatch.{{/footnote}}, while the SDMX Concepts can have different Representations in different DataStructures.{{footnote}}AConceptbecomesaComponentin aDataStructureDefinition,andComponentscanhavedifferentLocalRepresentationsindifferentDataStructureDefinitions,alsooverridingthe(possible)base representationoftheConcept.{{/footnote}}This means that one SDMX Concept can correspond to many VTL Variables, one for each representation the Concept has.579 +Another difference consists in the fact that all Value Domains are considered as identifiable objects in VTL either if enumerated or not, while in SDMX the Codelist (corresponding to a VTL enumerated Value Domain) is identifiable, while the SDMX non-enumerated Representation (corresponding to a VTL non-enumerated Value Domain) is not identifiable. As a consequence, the definition of the VTL Rulesets, which in VTL can refer either to enumerated or non-enumerated value domains, in SDMX can refer only to enumerated Value Domains (i.e. to SDMX Codelists). As for the mapping between VTL variables and SDMX Concepts, it should be noted that these artefacts do not coincide perfectly. In fact, the VTL variables are represented variables, defined always on the same Value Domain (“Representation” in SDMX) independently of the data set / data structure in which they appear^^[[(% 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" %)^^40^^>>path:#sdfootnote40sym||name="sdfootnote40anc"]](%%)^^, while the SDMX Concepts can have different Representations in different DataStructures.^^[[(% 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" %)^^41^^>>path:#sdfootnote41sym||name="sdfootnote41anc"]](%%)^^ This means that one SDMX Concept can correspond to many VTL Variables, one for each representation the Concept has. 509 509 510 510 Therefore, it is important to be aware that some VTL operations (for example the binary operations at data set level) are consistent only if the components having the same names in the operated VTL Data Sets have also the same representation (i.e. the same Value Domain as for VTL). For example, it is possible to obtain correct results from the VTL expression 511 511 512 -DS_c := DS_a + DS_b (where DS_a, DS_b, DS_c are VTL Data Sets) 583 +DS_c := DS_a + DS_b (where DS_a, DS_b, DS_c are VTL Data Sets) if the matching components in DS_a and DS_b (e.g. ref_date, geo_area, sector …) refer to the same general representation. In simpler words, DS_a and DS_b must use the same values/codes (for ref_date, geo_area, sector … ), otherwise the relevant values would not match and the result of the operation would be wrong. 513 513 514 -if the matching components in DS_a and DS_b (e.g. ref_date, geo_area, sector …) refer to the same general representation. In simpler words, DS_a and DS_b must use the same values/codes (for ref_date, geo_area, sector … ), otherwise the relevant values would not match and the result of the operation would be wrong. 515 - 516 516 As mentioned, the property above is not enforced by construction in SDMX, and different representations of the same Concept can be not compatible one another (for example, it may happen that geo_area is represented by ISO-alpha-3 codes in DS_a and by ISO alpha-2 codes in DS_b). Therefore, it will be up to the definer of VTL 517 517 587 +[[image:SDMX 3-0-0 SECTION 6 FINAL-1.0_en_59eee18f.gif||alt="Shape5" height="1" width="192"]] 588 + 518 518 Transformations to ensure that the VTL expressions are consistent with the actual representations of the correspondent SDMX Concepts. 519 519 520 520 It remains up to the SDMX-VTL definer also the assurance of the consistency between a VTL Ruleset defined on Variables and the SDMX Components on which the Ruleset is applied. In fact, a VTL Ruleset is expressed by means of the values of the Variables (i.e. SDMX Concepts), i.e. assuming definite representations for them (e.g. ISOalpha-3 for country). If the Ruleset is applied to SDMX Components that have the same name of the Concept they refer to but different representations (e.g. ISO-alpha-2 for country), the Ruleset cannot work properly. ... ... @@ -529,8 +529,7 @@ 529 529 530 530 [[image:SDMX 3-0-0 SECTION 6 FINAL-1.0_en_e3df33ae.png||height="543" width="483"]] 531 531 532 -(% class="wikigeneratedid" id="HFigure222013VTLDataTypes" %) 533 -**Figure 22 – VTL Data Types** 603 +==== Figure 22 – VTL Data Types ==== 534 534 535 535 The VTL scalar types are in turn subdivided in basic scalar types, which are elementary (not defined in term of other data types) and Value Domain and Set scalar types, which are defined in terms of the basic scalar types. 536 536 ... ... @@ -537,12 +537,131 @@ 537 537 The VTL basic scalar types are listed below and follow a hierarchical structure in terms of supersets/subsets (e.g. "scalar" is the superset of all the basic scalar types): 538 538 539 539 540 -**Figure 23 – VTL Basic Scalar Types** 541 541 542 542 ((( 543 - 612 +//n// 613 + 614 +//a// 615 + 616 +//e// 617 + 618 +//l// 619 + 620 +//o// 621 + 622 +//o// 623 + 624 +//B// 625 + 626 +//n// 627 + 628 +//o// 629 + 630 +//i// 631 + 632 +//t// 633 + 634 +//a// 635 + 636 +//r// 637 + 638 +//u// 639 + 640 +//D// 641 + 642 +//d// 643 + 644 +//o// 645 + 646 +//i// 647 + 648 +//r// 649 + 650 +//e// 651 + 652 +//p// 653 + 654 +//_// 655 + 656 +//e// 657 + 658 +//m// 659 + 660 +//i// 661 + 662 +//T// 663 + 664 +//e// 665 + 666 +//t// 667 + 668 +//a// 669 + 670 +//D// 671 + 672 +//e// 673 + 674 +//m// 675 + 676 +//i// 677 + 678 +//T// 679 + 680 +//r// 681 + 682 +//e// 683 + 684 +//g// 685 + 686 +//e// 687 + 688 +//t// 689 + 690 +//n// 691 + 692 +//I// 693 + 694 +//r// 695 + 696 +//e// 697 + 698 +//b// 699 + 700 +//m// 701 + 702 +//u// 703 + 704 +//N// 705 + 706 +//g// 707 + 708 +//n// 709 + 710 +//i// 711 + 712 +//r// 713 + 714 +//t// 715 + 716 +//S// 717 + 718 +//r// 719 + 720 +//a// 721 + 722 +//l// 723 + 724 +//a// 725 + 726 +//c// 727 + 728 +//S// 729 + 730 +[[image:SDMX 3-0-0 SECTION 6 FINAL-1.0_en_82d45833.gif||alt="Shape6" height="231" width="184"]] 544 544 ))) 545 545 733 +==== Figure 23 – VTL Basic Scalar Types ==== 734 + 546 546 === 12.4.2 VTL basic scalar types and SDMX data types === 547 547 548 548 The VTL assumes that a basic scalar type has a unique internal representation and can have more external representations. ... ... @@ -565,159 +565,204 @@ 565 565 566 566 The following table describes the default mapping for converting from the SDMX data types to the VTL basic scalar types. 567 567 568 -(% style="width:823.294px" %) 569 -|(% style="width:509px" %)**SDMX data type (BasicComponentDataType)**|(% style="width:312px" %)**Default VTL basic scalar type** 570 -|(% style="width:509px" %)((( 757 +|SDMX data type (BasicComponentDataType)|Default VTL basic scalar type 758 +|((( 571 571 String 760 + 572 572 (string allowing any character) 573 -)))| (%style="width:312px" %)string574 -|( % style="width:509px" %)(((762 +)))|string 763 +|((( 575 575 Alpha 765 + 576 576 (string which only allows A-z) 577 -)))| (%style="width:312px" %)string578 -|( % style="width:509px" %)(((767 +)))|string 768 +|((( 579 579 AlphaNumeric 770 + 580 580 (string which only allows A-z and 0-9) 581 -)))| (%style="width:312px" %)string582 -|( % style="width:509px" %)(((772 +)))|string 773 +|((( 583 583 Numeric 775 + 584 584 (string which only allows 0-9, but is not numeric so that is can having leading zeros) 585 -)))| (%style="width:312px" %)string586 -|( % style="width:509px" %)(((777 +)))|string 778 +|((( 587 587 BigInteger 780 + 588 588 (corresponds to XML Schema xs:integer datatype; infinite set of integer values) 589 -)))| (% style="width:312px" %)integer590 -|( % style="width:509px" %)(((782 +)))|integer 783 +|((( 591 591 Integer 592 -(corresponds to XML Schema xs:int datatype; between -2147483648 and +2147483647 (inclusive)) 593 -)))|(% style="width:312px" %)integer 594 -|(% style="width:509px" %)((( 785 + 786 +(corresponds to XML Schema xs:int datatype; between -2147483648 and +2147483647 787 + 788 +(inclusive)) 789 +)))|integer 790 +|((( 595 595 Long 596 -(corresponds to XML Schema xs:long datatype; between -9223372036854775808 and +9223372036854775807 (inclusive)) 597 -)))|(% style="width:312px" %)integer 598 -|(% style="width:509px" %)((( 792 + 793 +(corresponds to XML Schema xs:long datatype; between -9223372036854775808 and 794 + 795 ++9223372036854775807 (inclusive)) 796 +)))|integer 797 +|((( 599 599 Short 799 + 600 600 (corresponds to XML Schema xs:short datatype; between -32768 and -32767 (inclusive)) 601 -)))| (% style="width:312px" %)integer602 -| (% style="width:509px" %)Decimal (corresponds to XML Schema xs:decimal datatype; subset of real numbers that can be represented as decimals)|(% style="width:312px" %)number603 -|( % style="width:509px" %)(((801 +)))|integer 802 +|Decimal (corresponds to XML Schema xs:decimal datatype; subset of real numbers that can be represented as decimals)|number 803 +|((( 604 604 Float 805 + 605 605 (corresponds to XML Schema xs:float datatype; patterned after the IEEE single-precision 32-bit floating point type) 606 -)))| (% style="width:312px" %)number607 -|( % style="width:509px" %)(((807 +)))|number 808 +|((( 608 608 Double 810 + 609 609 (corresponds to XML Schema xs:double datatype; patterned after the IEEE double-precision 64-bit floating point type) 610 -)))| (% style="width:312px" %)number611 -|( % style="width:509px" %)(((812 +)))|number 813 +|((( 612 612 Boolean 613 -(corresponds to the XML Schema xs:boolean datatype; support the mathematical concept of binary-valued logic: {true, false}) 614 -)))|(% style="width:312px" %)boolean 615 615 616 -(% style="width:822.294px" %) 617 -|(% colspan="2" style="width:507px" %)((( 816 +(corresponds to the XML Schema xs:boolean datatype; support the mathematical concept of 817 + 818 +binary-valued logic: {true, false}) 819 +)))|boolean 820 + 821 +| |(% colspan="2" %)((( 618 618 URI 823 + 619 619 (corresponds to the XML Schema xs:anyURI; absolute or relative Uniform Resource Identifier Reference) 620 -)))|(% colspan=" 1"style="width:311px"%)string621 -|(% colspan="2" style="width:507px"%)(((825 +)))|(% colspan="2" %)string 826 +| |(% colspan="2" %)((( 622 622 Count 828 + 623 623 (an integer following a sequential pattern, increasing by 1 for each occurrence) 624 -)))|(% colspan=" 1"style="width:311px"%)integer625 -|(% colspan="2" style="width:507px"%)(((830 +)))|(% colspan="2" %)integer 831 +| |(% colspan="2" %)((( 626 626 InclusiveValueRange 833 + 627 627 (decimal number within a closed interval, whose bounds are specified in the SDMX representation by the facets minValue and maxValue) 628 -)))|(% colspan=" 1"style="width:311px"%)number629 -|(% colspan="2" style="width:507px"%)(((835 +)))|(% colspan="2" %)number 836 +| |(% colspan="2" %)((( 630 630 ExclusiveValueRange 838 + 631 631 (decimal number within an open interval, whose bounds are specified in the SDMX representation by the facets minValue and maxValue) 632 -)))|(% colspan=" 1"style="width:311px"%)number633 -|(% colspan="2" style="width:507px"%)(((840 +)))|(% colspan="2" %)number 841 +| |(% colspan="2" %)((( 634 634 Incremental 843 + 635 635 (decimal number the increased by a specific interval (defined by the interval facet), which is typically enforced outside of the XML validation) 636 -)))|(% colspan=" 1"style="width:311px"%)number637 -|(% colspan="2" style="width:507px"%)(((845 +)))|(% colspan="2" %)number 846 +| |(% colspan="2" %)((( 638 638 ObservationalTimePeriod 848 + 639 639 (superset of StandardTimePeriod and TimeRange) 640 -)))|(% colspan=" 1"style="width:311px"%)time641 -|(% colspan="2" style="width:507px"%)(((850 +)))|(% colspan="2" %)time 851 +| |(% colspan="2" %)((( 642 642 StandardTimePeriod 643 -(superset of BasicTimePeriod and ReportingTimePeriod) 644 -)))|(% colspan="1" style="width:311px" %)time 645 -|(% colspan="2" style="width:507px" %)((( 853 + 854 +(superset of BasicTimePeriod and 855 + 856 +ReportingTimePeriod) 857 +)))|(% colspan="2" %)time 858 +| |(% colspan="2" %)((( 646 646 BasicTimePeriod 860 + 647 647 (superset of GregorianTimePeriod and DateTime) 648 -)))|(% colspan=" 1"style="width:311px"%)date649 -|(% colspan="2" style="width:507px"%)(((862 +)))|(% colspan="2" %)date 863 +| |(% colspan="2" %)((( 650 650 GregorianTimePeriod 865 + 651 651 (superset of GregorianYear, GregorianYearMonth, and GregorianDay) 652 -)))|(% colspan=" 1"style="width:311px"%)date653 -|(% colspan="2" style="width:507px"%)GregorianYear (YYYY)|(% colspan="1"style="width:311px"%)date654 -|(% colspan="2" style="width:507px"%)GregorianYearMonth / GregorianMonth (YYYY-MM)|(% colspan="1"style="width:311px"%)date655 -|(% colspan="2" style="width:507px"%)GregorianDay (YYYY-MM-DD)|(% colspan="1"style="width:311px"%)date656 -|(% colspan="2" style="width:507px"%)(((867 +)))|(% colspan="2" %)date 868 +| |(% colspan="2" %)GregorianYear (YYYY)|(% colspan="2" %)date 869 +| |(% colspan="2" %)GregorianYearMonth / GregorianMonth (YYYY-MM)|(% colspan="2" %)date 870 +| |(% colspan="2" %)GregorianDay (YYYY-MM-DD)|(% colspan="2" %)date 871 +| |(% colspan="2" %)((( 657 657 ReportingTimePeriod 658 -(superset of RepostingYear, ReportingSemester, ReportingTrimester, ReportingQuarter, ReportingMonth, ReportingWeek, ReportingDay) 659 -)))|(% colspan="1" style="width:311px" %)time_period 660 -|(% colspan="2" style="width:507px" %)((( 873 + 874 +(superset of RepostingYear, ReportingSemester, 875 + 876 +ReportingTrimester, ReportingQuarter, 877 + 878 +ReportingMonth, ReportingWeek, ReportingDay) 879 +)))|(% colspan="2" %)time_period 880 +| |(% colspan="2" %)((( 661 661 ReportingYear 882 + 662 662 (YYYY-A1 – 1 year period) 663 -)))|(% colspan=" 1"style="width:311px"%)time_period664 -|(% colspan="2" style="width:507px"%)(((884 +)))|(% colspan="2" %)time_period 885 +| |(% colspan="2" %)((( 665 665 ReportingSemester 887 + 666 666 (YYYY-Ss – 6 month period) 667 -)))|(% colspan=" 1"style="width:311px"%)time_period668 -|(% colspan="2" style="width:507px"%)(((889 +)))|(% colspan="2" %)time_period 890 +| |(% colspan="2" %)((( 669 669 ReportingTrimester 892 + 670 670 (YYYY-Tt – 4 month period) 671 -)))|(% colspan=" 1"style="width:311px"%)time_period672 -|(% colspan="2" style="width:507px"%)(((894 +)))|(% colspan="2" %)time_period 895 +| |(% colspan="2" %)((( 673 673 ReportingQuarter 897 + 674 674 (YYYY-Qq – 3 month period) 675 -)))|(% colspan=" 1"style="width:311px"%)time_period676 -|(% colspan="2" style="width:507px"%)(((899 +)))|(% colspan="2" %)time_period 900 +| |(% colspan="2" %)((( 677 677 ReportingMonth 902 + 678 678 (YYYY-Mmm – 1 month period) 679 -)))|(% colspan="1" style="width:311px" %)time_period 680 -|(% colspan="2" style="width:507px" %)ReportingWeek|(% colspan="1" style="width:311px" %)time_period 681 -|(% 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" %) 682 -|(% colspan="1" style="width:507px" %)((( 904 +)))|(% colspan="2" %)time_period 905 +| |(% colspan="2" %)ReportingWeek|(% colspan="2" %)time_period 906 +| |(% colspan="2" %) |(% colspan="2" %) 907 +| |(% colspan="2" %) |(% colspan="2" %) 908 +|(% colspan="2" %)(YYYY-Www – 7 day period; following ISO 8601 definition of a week in a year)|(% colspan="2" %) | 909 +|(% colspan="2" %)((( 683 683 ReportingDay 911 + 684 684 (YYYY-Dddd – 1 day period) 685 -)))|(% colspan="2" style="width:312px"%)time_period686 -|(% colspan=" 1"style="width:507px"%)(((913 +)))|(% colspan="2" %)time_period| 914 +|(% colspan="2" %)((( 687 687 DateTime 916 + 688 688 (YYYY-MM-DDThh:mm:ss) 689 -)))|(% colspan="2" style="width:312px"%)date690 -|(% colspan=" 1"style="width:507px"%)(((918 +)))|(% colspan="2" %)date| 919 +|(% colspan="2" %)((( 691 691 TimeRange 921 + 692 692 (YYYY-MM-DD(Thh:mm:ss)?/<duration>) 693 -)))|(% colspan="2" style="width:312px"%)time694 -|(% colspan=" 1"style="width:507px"%)(((923 +)))|(% colspan="2" %)time| 924 +|(% colspan="2" %)((( 695 695 Month 926 + 696 696 (~-~-MM; speicifies a month independent of a year; e.g. February is black history month in the United States) 697 -)))|(% colspan="2" style="width:312px"%)string698 -|(% colspan=" 1"style="width:507px"%)(((928 +)))|(% colspan="2" %)string| 929 +|(% colspan="2" %)((( 699 699 MonthDay 931 + 700 700 (~-~-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) 701 -)))|(% colspan="2" style="width:312px"%)string702 -|(% colspan=" 1"style="width:507px"%)(((933 +)))|(% colspan="2" %)string| 934 +|(% colspan="2" %)((( 703 703 Day 936 + 704 704 (~-~--DD; specifies a day independent of a month or year; e.g. the 15^^th^^ is payday) 705 -)))|(% colspan="2" style="width:312px"%)string706 -|(% colspan=" 1"style="width:507px"%)(((938 +)))|(% colspan="2" %)string| 939 +|(% colspan="2" %)((( 707 707 Time 941 + 708 708 (hh:mm:ss; time independent of a date; e.g. coffee break is at 10:00 AM) 709 -)))|(% colspan="2" style="width:312px"%)string710 -|(% colspan=" 1"style="width:507px"%)(((943 +)))|(% colspan="2" %)string| 944 +|(% colspan="2" %)((( 711 711 Duration 946 + 712 712 (corresponds to XML Schema xs:duration datatype) 713 -)))|(% colspan="2" style="width:312px"%)duration714 -|(% colspan=" 1"style="width:507px"%)XHTML|(% colspan="2"style="width:312px"%)Metadata type – not applicable715 -|(% colspan=" 1"style="width:507px"%)KeyValues|(% colspan="2"style="width:312px"%)Metadata type – not applicable716 -|(% colspan=" 1"style="width:507px"%)IdentifiableReference|(% colspan="2"style="width:312px"%)Metadata type – not applicable717 -|(% colspan=" 1"style="width:507px"%)DataSetReference|(% colspan="2"style="width:312px"%)Metadata type – not applicable948 +)))|(% colspan="2" %)duration| 949 +|(% colspan="2" %)XHTML|(% colspan="2" %)Metadata type – not applicable| 950 +|(% colspan="2" %)KeyValues|(% colspan="2" %)Metadata type – not applicable| 951 +|(% colspan="2" %)IdentifiableReference|(% colspan="2" %)Metadata type – not applicable| 952 +|(% colspan="2" %)DataSetReference|(% colspan="2" %)Metadata type – not applicable| 718 718 719 -(% class="wikigeneratedid" id="HFigure142013MappingsfromSDMXdatatypestoVTLBasicScalarTypes" %) 720 -**Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types** 954 +==== Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types ==== 721 721 722 722 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). 723 723 ... ... @@ -725,32 +725,39 @@ 725 725 726 726 The following table describes the default conversion from the VTL basic scalar types to the SDMX data types . 727 727 728 -(% style="width:1073.29px" %) 729 -|(% style="width:207px" %)((( 730 -**VTL basic scalar type** 731 -)))|(% style="width:462px" %)((( 732 -**Default SDMX data type (BasicComponentDataType)** 733 -)))|(% style="width:402px" %)**Default output format** 734 -|(% style="width:207px" %)String|(% style="width:462px" %)String|(% style="width:402px" %)Like XML (xs:string) 735 -|(% style="width:207px" %)Number|(% style="width:462px" %)Float|(% style="width:402px" %)Like XML (xs:float) 736 -|(% style="width:207px" %)Integer|(% style="width:462px" %)Integer|(% style="width:402px" %)Like XML (xs:int) 737 -|(% style="width:207px" %)Date|(% style="width:462px" %)DateTime|(% style="width:402px" %)YYYY-MM-DDT00:00:00Z 738 -|(% style="width:207px" %)Time|(% style="width:462px" %)StandardTimePeriod|(% style="width:402px" %)<date>/<date> (as defined above) 739 -|(% style="width:207px" %)time_period|(% style="width:462px" %)((( 962 +|((( 963 +VTL basic 964 + 965 +scalar type 966 +)))|((( 967 +Default SDMX data type 968 + 969 +(BasicComponentDataType 970 + 971 +) 972 +)))|Default output format 973 +|String|String|Like XML (xs:string) 974 +|Number|Float|Like XML (xs:float) 975 +|Integer|Integer|Like XML (xs:int) 976 +|Date|DateTime|YYYY-MM-DDT00:00:00Z 977 +|Time|StandardTimePeriod|<date>/<date> (as defined above) 978 +|time_period|((( 740 740 ReportingTimePeriod 980 + 741 741 (StandardReportingPeriod) 742 -)))|( % style="width:402px" %)(((982 +)))|((( 743 743 YYYY-Pppp 984 + 744 744 (according to SDMX ) 745 745 ))) 746 -| (% style="width:207px" %)Duration|(% style="width:462px" %)Duration|(% style="width:402px" %)(((987 +|Duration|Duration|((( 747 747 Like XML (xs:duration) 989 + 748 748 PnYnMnDTnHnMnS 749 749 ))) 750 -| (% style="width:207px" %)Boolean|(% style="width:462px" %)Boolean|(% style="width:402px" %)Like XML (xs:boolean) with the values "true" or "false"992 +|Boolean|Boolean|Like XML (xs:boolean) with the values "true" or "false" 751 751 752 -(% class="wikigeneratedid" id="HFigure142013MappingsfromSDMXdatatypestoVTLBasicScalarTypes-1" %) 753 -**Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types** 994 +==== Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types ==== 754 754 755 755 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). 756 756 ... ... @@ -804,7 +804,7 @@ 804 804 |N|fixed number of digits used in the preceding textual representation of the month or the day 805 805 | | 806 806 807 -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 representationgiven in theDSDshouldobviouslybecompatible withtheVTLdata type.{{/footnote}}.1048 +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" %)^^42^^>>path:#sdfootnote42sym||name="sdfootnote42anc"]](%%)^^. 808 808 809 809 === 12.4.5 Null Values === 810 810 ... ... @@ -822,8 +822,10 @@ 822 822 823 823 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). 824 824 825 -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.1066 +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 826 826 1068 +TransformationScheme. 1069 + 827 827 In case a literal is operand of a VTL Cast operation, the format specified in the Cast overrides all the possible otherwise specified formats. 828 828 829 829 {{putFootnotes/}}
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