How to create a measure which is a count of all records with a certain flag?

[Anonymous]

I am trying to get create a measure which is a count of all records where flag1="yes". I am using this formula:

count1 = calculate(countrows('table1'),filter(all('table1'[uniqueID]),'table1'[flag1]="yes" )

I am getting this error:

"A single value for column 'flag1' in table 'program' cannot be determined. This can happen when a measure formula refers to a column that contains many values without specifying an aggregation such as min, max, count, or sum to get a single result."

Why is this? Is there another way to accomplish this?

[KHorseman · Accepted solution]

When you specify a column in an ALL() statement, it returns a table with that single column. The second column you refer to does not exist in that table. Your formula should be this:

CALCULATE(
	COUNTROWS('table1'),
	FILTER(
		ALL('table1'),
		'table1'[flag1] = "yes"
	)
)

Unless you were trying to use all('table1'[uniqueID]) to force the countrows to count each unique ID only once in a table that otherwise has duplicates. In that case you would want to do:

CALCULATE(
	DISTINCTCOUNT('table1'[uniqueID]),
	FILTER(
		ALL('table1'),
		'table1'[flag1] = "yes"
	)
)

[Anonymous]

It works, thanks!