# REST API: definition operations query version ids

**Category:** [ITS](https://discourse.openehr.org/c/its/41)
**Created:** 2021-12-13 14:53 UTC
**Views:** 428
**Replies:** 3
**URL:** https://discourse.openehr.org/t/rest-api-definition-operations-query-version-ids/2191

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## Post #1 by @thomas.beale

I just realised after we dropped the call that on the question of query formalism version id - if it's a non-numeric version id, i.e. just some name or string like '2019-3' or whatever, then the string could be nameversion - there would be no reliable way to distinguish the name part from the version part. Even worse, a query language could just be called something like AcmeQL20, and have numeric version ids.

So we are going to have to either have a separate field, or else a delimiter, e.g "AQL::1" or "AQL(2.3)" or similar, with plain "AQL" always being allowed as well.

Preferences for what kind of strings we want to allow? We have a precedent for using the '::' delimiter already, but I'm fine with other approaches.

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## Post #2 by @pablo

@thomas.beale besides the format, what you propose is that `formalism_id is formalism_name + formalism_version`, which I agree. Then formalism_version would be semver, which I also agree with.

I think that filed would be part of the `metadata` in the query JSON/XML representation, or some kind of common header, then the body would be the query representation for the specific formalism name and version.

That will open the door for ad-hoc or usage-specific/DSL query languages at the API/SM level, which is something I have been expecting for years now, I guess that will also help @sebastian.iancu and his implementation. :upside_down_face:

Sadly I couldn't be on today's meeting to hear the details in this topic's discussion.

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## Post #3 by @thomas.beale

[quote="pablo, post:2, topic:2191"]
Then formalism_version would be semver, which I also agree with
[/quote]

It could be, but we don't have control over how other orgs identify versions of their languages...

For now, I have gone with [this specification](https://specifications.openehr.org/releases/SM/latest/openehr_platform.html#_query_formalism).

See also other small modifications (rename 'formalism' field -> 'type' to match REST API) and others, as per SEC call 13 Dec 2021.

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## Post #4 by @pablo

[quote="thomas.beale, post:3, topic:2191"]
could be, but we don’t have control over how other orgs identify versions of their languages…
[/quote]

That is ok, I thought this was openEHR versioning but I see this might be versioning of the formalism by the organization that manages it.

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**Canonical:** https://discourse.openehr.org/t/rest-api-definition-operations-query-version-ids/2191
**Original content:** https://discourse.openehr.org/t/rest-api-definition-operations-query-version-ids/2191