Sorting a Gallery Populated By Two Dataverse Tables Via Lookup Column - Unable to Sort by a Parent Table Column

[cmanning]

I am building a canvas app with two Dataverse tables  and I can display items from both tables per the lookup column DRID.  The parent table DealIntakeApp has a text column (Name - contains unique ID) which is referenced in the child table AssignedUsers.DRID lookup column.  Below in the Relationships tab from Dataverse.

In my gallery (GalleryNewReports) I can reference values from either table per my examples below.  When I reference values from the DealIntakeApp table, I use for example ThisItem.DRID.SFDCOppID, while referencing a value from AssignedUsers table is straightforward. 

// From AssignedUsers table
ThisItem.'Assigned-Full-Name'

// DealIntakeApp table - Used the lookup column DRID in AssignedUsers table, DRID dot syntax 
// to retrieve SFDCOppName values from the DealIntakeApp table  
ThisItem.DRID.SFDCOppName

The Issue: I need to sort the GalleryNewReports by a column in the DealIntakeApp table but I can't use the AssignedUsers.DRID.SFDCOppName method to use in sorting.  What am I missing? 
Here is a visual reference.

[dpoggemann]

Hi @cmanning ,

Can you show example of how your are trying to sort?  Have you tried putting the rows into a Collection sorting the collection to display the records in the GalleryNewReports?

[cmanning]

@dpoggemann - Thank you for your response.

// Works - I can sort gallery by column but only IF the column is in the AssignedUserss table
SortByColumns( AssignedUserss, "cr4de_assignedfullname" ) 

// Can access items from both tables in the gallery
// Access data in the DealIntakeApp table by using ThisItem.DRID.DealIntakeAppColumnName
ThisItem.DRID.SFDCOppName

// However, I cannot sort by a column in the DealIntakeApp table 
/// THIS IS WHAT I NEED A SOLUTION FOR - SortbyColumns using SFDCOppName

 If I used a collection, are they any easier to sort or will I see the same issue?  Can you provide an example of how to create a new collection from two Dataverse tables with a lookup column creating a relationship between the tables?

[cmanning]

Anyone know how to sort a canvas app gallery with fields from 2 related Dataverse tables? 

[cmanning]

Bump

[cmanning · Accepted solution]

For those interested in the solution here it is.

SortByColumns(AddColumns(AssignedUserss, "sortby", DRID.SFDCOppName), "sortby", Ascending)