Help with evaluating some DAX code

[ArchStanton]

Hi,

I'm struggling to work out how this piece of code is being being evaluated, in particular what is being calculated first, second and so on. If some could break it down to show what each step is in order it would be a great help.

Also, Is there a way of making this code simpler using Variables?

Days ERT to Outcome = 
IF (
    NOT ( ISBLANK ( 'Cases'[ERT Start FlagDate] )),
    IF (
        ISBLANK ( 'Cases'[formofauthorityreceiveddate] ),
        DATEDIFF (
            IF (
                'Cases'[Created Date] > 'Cases'[ERT Start FlagDate],
                'Cases'[Created on],
                'Cases'[ERT Start FlagDate]
            ),
            IF ( ISBLANK ( 'Cases'[ERT End FlagDate] ), NOW (), 'Cases'[ERT End FlagDate] ),
            DAY
        ),
        DATEDIFF ( 'Cases'[ERT Start FlagDate], 'Cases'[ERT End FlagDate], DAY )
    ),
    BLANK ()
)

Thanks,

[jdbuchanan71 · Accepted solution]

IF statements work from the top in so it check 1, the 2 etc:

It startts with 1 and IF 'Cases[ERT Start Flag Date] is not blank it goes to section A which starts the 2 check, if it is blank it gos to B and returns a BLANK().

[jdbuchanan71 · Accepted solution]

IF statements work from the top in so it check 1, the 2 etc:

It startts with 1 and IF 'Cases[ERT Start Flag Date] is not blank it goes to section A which starts the 2 check, if it is blank it gos to B and returns a BLANK().

[mlsx4 · Accepted solution]

Hi @ArchStanton 

The explanation from @jdbuchanan71 is perfect. Regarding your second question, you can use variables in this way:

Days ERT to Outcome = 

var _startFlag= ISBLANK ( 'Cases'[ERT Start FlagDate] )
var _endFlag= ISBLANK ( 'Cases'[ERT End FlagDate] )

IF (
    NOT ( _startFlag),
    IF (
        ISBLANK ( 'Cases'[formofauthorityreceiveddate] ),
        DATEDIFF (
            IF (
                'Cases'[Created Date] > 'Cases'[ERT Start FlagDate],
                'Cases'[Created on],
                'Cases'[ERT Start FlagDate]
            ),
            IF ( _endFlag , NOW (), 'Cases'[ERT End FlagDate] ),
            DAY
        ),
        DATEDIFF ( 'Cases'[ERT Start FlagDate], 'Cases'[ERT End FlagDate], DAY )
    ),
    BLANK ()
)

However, as you can see, it doesn't make much sense. Variables avoid repetitive calculus, but in this case, you don't have repetitive pieces

[ArchStanton]

Really grateful for your reply as well, many thanks