I need help in understanding how Dimension={} works. I understand the Dimesnion = works (removing the selection).
From definition, I came to know that Dimension={} means no selection. Can someone explain what is the difference. I tried but not getting. If possible, please explain with an example.
I don't think these blog posts will explain the set modifier using {}.
I haven't seen this used ever, so indeed, I think that's a good question.
Given a sample set like
LOAD Recno() as ID, If(RAND()<0.2, NULL(), Recno()) as Number
AutoGenerate 20;
=Count({<Number -= {}>}[ID])
will return the same as
=Count({<Number *= {"*"}>}ID)
I was not able to count the ID records with NULL in Number, using something like
=Count({<Number = {}>} [ID])
(which makes sense to me, since I believe we need to create a modifier that returns a non empty set.
You can use other methods to exclude NULL as mentioned in the blog post as well)
Maybe hic can explain what the use case for {} is (in the scope of a field modifier as mentioned in the HELP:
The syntax in the two previous examples is interpreted as “no selections” in 'Region', that is to say all regions given other selections will be possible. It is not equivalent to the syntax <Region = {}> (or any other text on the right side of the equal sign implicitly resulting in an empty element set) which is interpreted as no region.
I did not understand this. Lets say I have a table with Year and Product and the set analysis like this:
=sum({<Product={}>}Sales). This always results in 0 meaning any selection results in 0. then why do i need this expression anymore.
Dimension={} returns an empty set. I what scenario, I need an empty set. If someone can explain this with a use case for this that would be appreciated.
By which statement you are quoting I am disqualifying others?
I am very clear on my statement and you do not need to state that. I did not disqualify any one here. I always appreciate and respect those who help me. So please do not divert/stop the discussion by simply creating a false impression on me.
I need help in understanding how Dimension={} works. I understand the Dimesnion = works (removing the selection).
From definition, I came to know that Dimension={} means no selection. Can someone explain what is the difference. I tried but not getting. If possible, please explain with an example.
Thanks in advance for your help
To answer part of your question:
To my understanding, the difference between
{<Dimension = >}
and
{<Dimension = {} >}
is that first is clearing the active selection in field Dimension, which basically assigns Dimension the full (only restricted by selections in other fields) set of possible values.
While second should create an empty set that should be used in the set analysis.
That's how I understand the syntax.
But as I mentioned, I haven't seen this in use and I currently don't see a real use case. That's why I tried to get Henric into the discussion. Maybe he can shed some light on this.
