[CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Francisco Luque Rodrigue — Fri, 12 May 2023 12:55:29 GMT

Any feedback in how to select one specific object instead the first one?

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Jan Šlegr — Fri, 28 Oct 2022 17:39:04 GMT

[quote userid="297179" url="~/products/programming/microstation_programming/f/microstation-programming---forum/234626/connect-item-type-getrelatedinstance-expression-select-specific-instance/731146"]What happens to the relationship info when you export or publish to imodel?[/quote]

Mark is (more or less) right, but complete answer is not (and cannot be) simple, because the publishing process is a transformation between two different worlds. Even when EC data in PowerPlatform and in iModel are "only" another versions of the same technology, there are plenty of structural changes and some features can be persisted in different way. So it depends on the transformation process, how specific relationship is transformed.

Yes, ECSQL is one from core features of iTwin.js / iModel ecosystem. But, depending how data are transformed, the query is different in PowerPlatform and iModel, both because different query mechanism (ECQuery vs ECSQ) and data structure is probably different.

With regards,

Jan

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Jon Summers — Thu, 27 Oct 2022 13:13:30 GMT

[quote userid="334014" url="~/products/programming/microstation_programming/f/microstation-programming---forum/234626/connect-item-type-getrelatedinstance-expression-select-specific-instance/738919"]I'm not too familiar with ecsql - how could i use that?[/quote]

ECSQL is iTwin technology. Unfortunately, it's not available in MicroStation — if only it were available!

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Mark Shamoun — Thu, 27 Oct 2022 12:33:44 GMT

As far as i know i would think that relationship info would be retained. I'm not too familiar with ecsql - how could i use that?

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Mark Shamoun — Thu, 27 Oct 2022 12:31:18 GMT

Hi Jan,

Sample dgn here with an ORD model that has GetRelatedInstance expressions on the corridor meshes that gets the related corridor they are part of and then finds a related linear feature and gets its length.

Because there are many linear features in the corridor, what we would like to be able to do is somehow select any one of these features specifically by something like a query or even collection index instead of it only selecting the first one.

communities.bentley.com/.../ord_5F00_corridor_2D00_getrelatedinstance_5F00_test.dgn

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Jan Šlegr — Wed, 14 Sep 2022 12:31:32 GMT

Hi Mark,

do you have any (preferably small) example of such design? As not regular ORD user, right I have no model with mesh available on my computer. Although Civil Browser is useful often, it does not always show exact EC classes structure, so to compare it with real DGN and (in the best case) model EC dump file, can provide clearer picture of the situation.

Regards,

Jan

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

dominic SEAH — Sun, 11 Sep 2022 06:14:32 GMT

Hi Mark,

What happens to the relationship info when you export or publish to imodel?

Maybe you can leverage ecsql there?

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Jon Summers — Sat, 10 Sep 2022 07:28:49 GMT

Unfortunately not: Expressions are...

Hard to understand
Non-intuitive
Poorly documented
Lacking in examples
Without debugging tools

[quote userid="334014" url="~/products/programming/microstation_programming/f/microstation-programming---forum/234626/connect-item-type-getrelatedinstance-expression-select-specific-instance/729039"]The "Civil Display Browser" interface in ORD. It visually maps the EC relationships of the Civil model to easier understand the links[/quote]

Why isn't that tool in vanilla MicroStation? The vertical apps could then use the base tool for their particular relationships.

I have read statements by Bentley staff that Expressions are like SQL. However, anything less like SQL than the expression in your first post is hard to imagine. It's not as if the technology is impossible: look what iTwin technology has to offer!

Perhaps Mangesh.Shelar could comment?

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Mark Shamoun — Sat, 10 Sep 2022 04:45:23 GMT

Any ideas?

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Ryan McCormack — Tue, 30 Aug 2022 23:28:59 GMT

Thanks Mark. That is very helpful.

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Mark Shamoun — Tue, 30 Aug 2022 09:18:42 GMT

Hey Ryan,

That is the "Civil Display Browser" interface in ORD. It visually maps the EC relationships of the Civil model to easier understand the links (it took me a while to know what it actually was until recently),

RE: [CONNECT] Item Type GetRelatedInstance Expression: select specific instance?

Ryan McCormack — Sun, 28 Aug 2022 21:43:22 GMT

Hi Mark,

Great question, I hope somebody is able to assist with this. In regards to the image in your question, how are you getting that information presented in that format?

Regards,

Ryan