Core concepts
URN Syntax
urn:sdmx:org.sdmx.infomodel.codelist.Codelist=SDMX:CL_FREQ(2.1)
An SDMX URN is composed of five parts:
URN prefix — urn:sdmx:org.sdmx.infomodel
This is unique to SDMX and has a fixed value
SDMX Structure - codelist.Codelist
Each structure is uniquely identified by its package and its class name.
See SDMX Structures for the full list of SDMX structures.
SDMX Agency ID — SDMX
Identifies the Agency responsible for maintaining the structure. The Agency ID helps the resolver locate the authoritative source.
See SDMX Agency for more details.
Structure ID — CL_FREQ
A unique identifier for the structure. The structure ID is defined by the maintaining Agency when the structure is first created.
Structure Version — 2.1
The version of the structure, also defined by the Agency. Versions may use a two-part format (e.g. 1.0) or a three-part semantic version format (e.g., 1.0.0 = major.minor.patch). For semantically versioned structures, the resolver can automatically find the latest available version.
See Structure Versioning for more details.
Sub-Structres
URNs are also used to identify structures that are contained inside a parent struture, for example a Code within a Codelist.
For sub-structures, the URN changes in two ways.
- The target structure type changes.
- The ID of the sub-structure is appended to the end of the URN
urn:sdmx:org.sdmx.infomodel.codelist.Code=SDMX:CL_FREQ(2.1).A
Resolving Sub-Structres
The URN resolver service is able to resolve specific Items in an Item Schemes by returning the parent structure as a partial list. For URNs that do not belong to an item sheme, the URN resolver will return the parent structure.
Examples
| URN (excluding the URN prefix for readablility) | Returns |
|---|---|
| codelist.Codelist=SDMX:CL_FREQ(2.1) | Codelist CL_FREQ as a full list of frequency Codes |
| codelist.Code=SDMX:CL_FREQ(2.1).A | Codelist CL_FREQ as a Partial list containing only Code 'A' |
| datastructure.Dimension=ESTAT:NA_MAIN93(1.7).ADJUSTMENT | Data Structure Definition containing the ADJUSTMENT Dimension |