Inspired by this great video and as a follow up to my last post regarding the Mastering DAX workshop I want to tell you about my findings regarding the DAX language:
DAX is simple,
but it is not easy.
This is so true. When I was sitting in the classroom, I realized in every example we did how true this statement is. If you see a working DAX formula you are tempted to say: “OK, no problem, this is easy”. But making a working DAX measure – which is really working all the time – no matter what the user is doing in terms of filtering and grouping is hard work.
If your measure is working in one situation but not in all situations
then your measure was wrong from the beginning.
Again, in many cases it seems that a measure is working. But as soon as you are changing some parameters or add an extra step of complexity it is not working at all. In many cases this means go back to start and do your work again.
Stick with the basics
Don’t bother about sophisticated functions.
Put all your efforts into filter context, row context, iterations, and context transition. I am still learning the hard way that this is the only way to success.
You can’t learn DAX by copying formulas
or patterns from the internet or books.
I tend to learn new things by browsing the internet. If I find a solution which is pointing me in the right direction, I usually succeed in solving my problem. With DAX I first thought ok cool do it in the same way at sometimes it seems to work but unfortunately other times not. So learning the basics is so important not just insert some CALUCULATE command here and there.
You can’t learn DAX by reading books
Only by practicing.
I have bought quite a few books in the past and by studying them I was fooling myself. I thought I know enough about DAX now. But the truth is I knew nothing. As soon as you are doing real live examples you will realize that without a solid understanding of the basics you are caught in an endless try and error loop.
So having learned all of this I feel at least in a position which points me in the right direction.
With every project I will gain confidence but nevertheless frustration will be my good companion for quite some time.
Stick to the basics
and try to think the DAX way.