View source for URN

[[Category:SDMX Structures]]
[[Category:How_To]]
=Overview=
A URN is an abbreviation for [https://en.wikipedia.org/wiki/Uniform_Resource_Name '''U'''niform '''R'''esource '''N'''ame].  The URN, as used by the SDMX specification, is a globally unique identifier to any [[Identifiable]] SDMX Structure.

The URN is used as a mechanism to link structures togeather without having to know the exact location of the structure, this is how the URN differs from a URL, the former provides a long lasting referneces which is agnostic to location, the latter provides a precise location of where to obtain the resource.

=Structure of a SDMX URN=
A URN is made up of 2 to 3 parts, depending on the type of structure being referenced.
# Namespace 
# Reference to the [[Maintainable]] Structure
# Reference to the [[Identifiable]] Structure (if the URN is referencing a Structure within a Maintianable, i.e a Code within a Codelist)

==URN Namespace==
The URN Namespaces are defined by SDMX, and take the following syntax:

[[File:URN Namespace.png|700px]]

The prefix for all SDMX Structural Metadata is '''urn:sdmx:org.sdmx.infomodel'''.   The Package and Class are used to represent the type of structure being referenced.  


==URN Identifiers==
The URN Namespace identifies which type of Structure is being referneced, i.e a Codelist, Data Structure, Concept, etc.

The subsequent properties in the URN Namespace are used to Identify the structure, starting with the [[Maintainable]]  identifiers, which are:
# Agency Id
# [[Identifiable|Id]]
# Version

[[File:URN Maintainable.png|700px]]

If the structure is not a [[Maintainable]] structure, but instead lives inside one, i.e a Code which lives inside a Codelist or a Dimension which lives inside a Data Structure, then the remainder of the URN is used to identify the structure inside the Maintainable parent. 

[[File:URN Identifiable.png|700px]]

For structures which live nested inside others, i.e a Category which is a number of levels deep, the nesting is part of the URN identifiation.

'''urn:sdmx:org.sdmx.infomodel.categoryscheme.Category=SDMX:STAT_SUBJECT_MATTER(1.0).DEMO_SOCIAL_STAT.HEALTH'''

Where the '''HEALTH''' Category is a child of the '''DEMO_SOCIAL_STAT''' Category.

== URN Examples ==
{| class="wikitable sortable"
|-
! Structure Type !! Package !! Class !! Parent !! Example
|-
| Agency Scheme|| base || AgencyScheme || - || urn:sdmx:org.sdmx.infomodel.base.AgencyScheme=SDMX:AGENCIES(1.0)
|-
| Agency || base|| Agency ||  AgencyScheme  || urn:sdmx:org.sdmx.infomodel.base.Agency=SDMX
|-
| Data Provider Scheme || base|| DataProviderScheme ||  - || urn:sdmx:org.sdmx.infomodel.base.DataProviderScheme=FAO:DATA_PROVIDERS(1.0)
|-
| Data Provider || base|| DataProvider ||  DataProviderScheme  || urn:sdmx:org.sdmx.infomodel.base.DataProvider=FAO:DATA_PROVIDERS(1.0).FR2
|-
| Data Consumer Scheme || base|| DataConsumerScheme ||  - || urn:sdmx:org.sdmx.infomodel.base.DataConsumerScheme=FAO:DATA_CONSUMERS(1.0)
|-
| Data Consumer || base|| DataConsumer ||  DataConsumerScheme  || urn:sdmx:org.sdmx.infomodel.base.DataConsumer=FAO:DATA_PROVIDERS(1.0).FR2
|-
| Organisation Unit Scheme || base || OrganisationUnitScheme ||  - || urn:sdmx:org.sdmx.infomodel.base.OrganisationUnitScheme=FAO:UNITSCHEME_A(1.0)
|-
| Organisation Unit|| base || OrganisationUnit ||  OrganisationUnitScheme  || urn:sdmx:org.sdmx.infomodel.base.OrganisationUnit=FAO:UNITSCHEME_A(1.0).STATS
|-
| Categorisation || categoryscheme|| Categorisation || -  || urn:sdmx:org.sdmx.infomodel.categoryscheme.Categorisation=IMF:CAT1(1.0)
|-
| Category Scheme || categoryscheme|| CategoryScheme || -  || urn:sdmx:org.sdmx.infomodel.categoryscheme.CategoryScheme=SDMX:STAT_SUBJECT_MATTER(1.0)
|-
| Category  || categoryscheme|| Category || CategoryScheme  || urn:sdmx:org.sdmx.infomodel.categoryscheme.Category=SDMX:STAT_SUBJECT_MATTER(1.0).DEMO_SOCIAL_STAT
|-
| Reporting Taxonomy  || categoryscheme|| ReportingTaxonomy || - || urn:sdmx:org.sdmx.infomodel.categoryscheme.ReportingTaxonomy=SDMX:RT(1.0)
|-
| Reporting Category|| categoryscheme|| ReportingCategory || ReportingTaxonomy || urn:sdmx:org.sdmx.infomodel.categoryscheme.ReportingCategory=SDMX:RT(1.0).CAT1
|-
| Concept Scheme || conceptscheme || ConceptScheme || -|| urn:sdmx:org.sdmx.infomodel.conceptscheme.ConceptScheme=SDMX:CROSS_DOMAIN_CONCEPTS(2.0)
|-
| Concept || conceptscheme || Concept || ConceptScheme || urn:sdmx:org.sdmx.infomodel.conceptscheme.Concept=SDMX:CROSS_DOMAIN_CONCEPTS(2.0).FREQ
|-
| [[Codelist]] || codelist || Codelist  || -  || urn:sdmx:org.sdmx.infomodel.codelist.Codelist=SDMX:CL_FREQ(2.0)
|-
| Code || codelist || Code || Codelist || urn:sdmx:org.sdmx.infomodel.codelist.Code=SDMX:CL_FREQ(2.0).A
|-
| Data Structure || datastructure || DataStructure || -  || urn:sdmx:org.sdmx.infomodel.datastructure.DataStructure=ESTAT:CPI(1.1)
|-
| Attribute List || datastructure || AttributeDescriptor || DataStructure   || urn:sdmx:org.sdmx.infomodel.datastructure.AttributeDescriptor=ESTAT:CPI(1.1).AttributeDescriptor
|-
| Attribute || datastructure || DataAttribute || AttributeDescriptor  || urn:sdmx:org.sdmx.infomodel.datastructure.DataAttribute=ESTAT:CPI(1.0).DISS_ORG
|-
| Dimension List || datastructure || DimensionDescriptor || DataStructure   || urn:sdmx:org.sdmx.infomodel.datastructure.DimensionDescriptor=ESTAT:CPI(1.1).DimensionDescriptor
|-
| Dimension || datastructure || Dimension || DimensionDescriptor   || urn:sdmx:org.sdmx.infomodel.datastructure.Dimension=ESTAT:CPI(1.0).FREQ
|-
| Group List || datastructure || GroupDimensionDescriptor || DataStructure   || urn:sdmx:org.sdmx.infomodel.datastructure.GroupDimensionDescriptor=ESTAT:CPI(1.1).SiblingGroup
|-
| Measure List || datastructure || MeasureDescriptor || DataStructure     || urn:sdmx:org.sdmx.infomodel.datastructure.MeasureDescriptor=ESTAT:CPI(1.1).MeasureDescriptor
|-
| Primary Measure || datastructure || PrimaryMeasure || MeasureDescriptor || urn:sdmx:org.sdmx.infomodel.datastructure.PrimaryMeasure=ESTAT:CPI(1.1).OBS_VALUE
|-
| Time Dimension|| datastructure || TimeDimension || DataStructure  || urn:sdmx:org.sdmx.infomodel.datastructure.TimeDimension=ESTAT:CPI(1.0).TIME_PERIOD
|-
| Metadata Structure|| metadatastructure || MetadataStructure || -  || urn:sdmx:org.sdmx.infomodel.metadatastructure.MetadataStructure=METADATA:MSD-V11(1.0)
|-
| Report Structure|| metadatastructure || ReportStructure|| MetadataStructure  ||
|-
| Metadata Attribute|| metadatastructure|| MetadataAttribute || ReportStructure  ||
|-
| Metadata Target || metadatastructure|| MetadataTarget || MetadataStructure    ||
|-
| Metadata Target (URN) || metadatastructure || IdentifiableObjectTarget || MetadataTarget  ||
|-
| Metadata Target (Dimension Values) || metadatastructure|| DimensionDescriptorValuesTarget || -  ||
|-
| Metadataflow || metadatastructure|| Metadataflow || -  || 	urn:sdmx:org.sdmx.infomodel.metadatastructure.Metadataflow=METADATA:MDF-V11(1.0)
|-
| Process || process || Process|| -  ||
|-
| Process Step|| process || ProcessStep || Process  ||
|-
| Transition || process || Transition ||  ProcessStep   ||
|-
| Provision Agreement|| registry || ProvisionAgreement || -  || urn:sdmx:org.sdmx.infomodel.registry.ProvisionAgreement=WB:GCI_WB(1.0)
|-
| Content Constraint || registry|| ContentConstraint || -  || urn:sdmx:org.sdmx.infomodel.registry.DataConstraint=A9_7_0:SC_HC025(1.0)
|-
| Structure Set || mapping || StructureSet || -  ||
|-
| Structure Map || mapping || Structure Map|| StructureSet   ||
|-
| Category Scheme Map || mapping  || CategorySchemeMap || StructureSet     ||
|-
| Concept Scheme Map || mapping  || ConceptSchemeMap || StructureSet     ||
|-
| Codelist Map || mapping || CodelistMap|| StructureSet     ||
|-
| Component Map || mapping || ComponentMap || StructureSet     ||
|-
| Organisation Scheme Map|| mapping || OrganisationSchemeMap || StructureSet ||
|}