Showing fields from "grandparent" table in model-driven power app view

[MatMd]

I am building a model-driven power app and I regularly have a situation where:

- "Child" table has an N->1 relationship to "Parent" table

- "Parent" table has an N->1 relationship to "Grandparent" table

- When I'm looking at a view of records in the Child table I really need to be able to show the "grandparent" name.

Power Apps seems to allow me to show column values from directly related tables, but not indirectly related tables.  Is there any solution / workaround to this?

If not, is this a feature that could be added?

[SBax · Accepted solution]

This is not possible unfortunately.

I have achieve something like this in the past, but it took a fair bit of work, and it relied on having the same set of fields in all three records (grandparent, parent, child) and a mechanism to update the fields when a change is made

Option 1 - Field Mapping - this option only works if you are creating parent/child from a subgrid

• Set up field mapping to pass the fields from the grandparent to the parent (assuming this is created from a subgrid within grandparent, and repeat the same for passing from parent to child)
• Limitations - if the field values update in a higher record, they are not updated in the lower one automatically

Option 2: Javascript - only works if records are created only from the UI (i.e. not by some other means, like a Flow)

• Write a script to run on save of a child record to get the grandparent record (via the parent record), and write the fields to fields with the same name in the child record.
• Limitations: field values in the child record will only update when the record is saved. If the app is heavily used, with lots of saving of child records, this could consume a lot of API calls.

Option 3 - Flow

• Write a flow that runs on create on a child, finding the parent, then the grandparent, and write to a set of fields on the childs record
• Write a second flow that when a grandparent record is updated, list parents related to the grandparent, and write data to the relevent fields on parent, then list children of the parent, and write to those fields (you could skip writing to the parent, and just write to the children if you prefer)
• limitations - again, could use a lot of API calls in an app that is heavily used

Happy to discuss either of the above options in more detail if these seem suitable

[MatMd]

Thanks -- I feared that this might be the case.

[Civil212]

Could you help regarding the third solution, !! 

Is there a tutorial or video explaining this way !!

[PowerBi-Rick]

I am trying to figure out the Option 1 - Field Mapping. I have a Grandparent Incident Table with IncidentId as primary key, a Parent Person Table with IncidentId from Grandparent and PersonId as primary key, and an Injury Table with InjuryId as Primary Key. Person has IncidentId as a lookup column to Incident and Injury has PersonId as a lookup column to Person. I have an IncidentId column in Injury but I am not sure if the lookup should be to the IncidentId value in Person or directly back to the IncidentId primary key in Incident

I have an Incident Form that contains a Person Subgrid and by clicking on Add New Person Record that correctly brings over the IncidentId from Incident. I am struggling with how to get the IncidentId into Injury. Using an Injury Subgrid on the Person form I can get PersonId into Injury but not IncidentId. 

How should this be mapped and where does IncidentId need to be on the Person form to get that value passed over to Injury?

[PowerBi-Rick]

Found the answer about Mapping at https://learn.microsoft.com/en-us/power-apps/maker/data-platform/map-entity-fields

Here is what worked for me:

1. IncidentId column in Person table Lookup to Incident Table

2. PersonId column in Injuries table Lookup to Person table

3. IncidentId column in Injuries table Lookup to Incident Table

4. Go into in classic mode and add the mapping from Person Table IncidentId column to Injury Table IncidentId column