I have done a tonne of research and reading on qlik sense, but can't seem to get my head around the differences between {1} and 1 when it comes to set modifiers.
For example, for the following two expressions, I get the same result and both change as user selections are made on the filter:
a) Count({<Customer={'X'}>}distinct [SaleNumber])
b) Count({1}{<Customer={'X'}>}distinct [SaleNumber])
However, the following remains static, despite any chances in customer selections made:
c) Count({1<Customer={'X'}>}distinct [SaleNumber])
Can someone please help explain what the difference is between set modifiers {1} and 1 and whether placement of the modifier has any impact?
It's not really difference between 1 and {1}; because '1' alone i.e. - without curly brackets is not valid in set analysis. Now I will try to explain why you see the difference in behaviour in both scenarios.
b) Count({1}{<Customer={'X'}>}distinct [SaleNumber]) - For this you are actually having two set analysis components separately(set analysis starts with '{' and ends with '}'), and in set analysis in such cases later one overrides the previous one. That means, in this case, {1} is invalid. Hence the result.
And for your third case, it's a single set analysis (one staring '{' and one closing '}'), therefore it behaves as expected.
That means you need to write {1} only when you want to disregard ALL fields selection, like : Sum({1} Sales). And use '{1<...' when want to disregard ALL fields with some additional conditions, like : Sum({1<ID={'$(=Max(ID))'} Sales).
