Join Tables in PowerFX

Nested Galleries

Multiple Gallery will lead to multiple scrolls in the 2nd level which is nasty.

However, two dimension nested gallery may work, i.e. level 1 gallery goes from left to right, and level 2 gallery goes from top to bottom.

Single Gallery with Grouped Items

Use a single gallery with grouped items technique

Data Join - The ForAll Technique

Using ForAll return nothing

ForAll(
    colAppEvents,
    Collect(
        colAppParties,
        Filter(
            'Application Parties',
            ThisRecord.Application.Application = Application.Application
        )
    )
);

Using ForAll with Alias for the outer loop

ForAll(
    colAppEvents As appEvent,
    Collect(
        colAppParties,
        Filter(
            'Application Parties',
            ThisRecord.Application.Application = appEvent.Application.Application
        )
    )
);

Using ForAll with With. With establish a temp variable

ForAll(
    colAppEvents,
    With(
        {currentApp: ThisRecord.Application.Application},
        Collect(
            colAppParties,
            Filter(
                'Application Parties',
                ThisRecord.Application.Application = currentApp
            )
        )
    )
)

Data Join - The Ungroup Technique

JOIN All Columns From Another Collection

Scope Ambiguity

Power Fx explained: Record scope, scope ambiguity and disambiguation

Single Quote vs Double Quote

SortByColumns is still using double quote to specify columns whereas AddColumns is using single quote to specify columns, or no quote if the column name has no spaces or speical characters.

Power Fx: Column names escape double quotes