Approach to generate a sample of records for each group of records in a table

[Corey-Flinders]

Hi All,

I have a table that contains data for years 2005 to 2018. I need to generate a sample of records for each year in the table. My working DAX expression looks like this:

Sample Table = UNION(
    SAMPLE(
        10,
        FILTER('Consolidated Data', AND('Consolidated Data'[Year Commenced] = 2005, ISBLANK('Consolidated Data'[Year Completed]) = FALSE)),
        'Consolidated Data'[Student ID]
    ),
    SAMPLE(
        10,
        FILTER('Consolidated Data', AND('Consolidated Data'[Year Commenced] = 2006, ISBLANK('Consolidated Data'[Year Completed]) = FALSE)),
        'Consolidated Data'[Student ID]
    ),
    SAMPLE(
        10,
        FILTER('Consolidated Data', AND('Consolidated Data'[Year Commenced] = 2007, ISBLANK('Consolidated Data'[Year Completed]) = FALSE)),
        'Consolidated Data'[Student ID]
    )
)

While this approach works, it feels wrong. I'm copying and pasting each call to the SAMPLE function and only changing the filter, and then using the UNION function to consolidate the returned records together into a single table.

Does anyone have any suggestions for an alternative approach?

With thanks.

-Corey

[d_gosbell · Accepted solution]

You could use a pattern like the following to avoid duplicating code, you then just add to the list of years that you are generating over (or you could use the GENERATESERIES() function to generate a continuous list of years)

Sample Table = 
SELECTCOLUMNS(
	GENERATE( {2005,2006,2007},
		SAMPLE(
			10,
			FILTER('Consolidated Data', AND('Consolidated Data'[Year Commenced] = [VALUE], ISBLANK('Consolidated Data'[Year Completed]) = FALSE)),
			'Consolidated Data'[Student ID]
		)
	)
	, "Student ID"
	,[Student ID]
)