- Know where you want to start and end, or you’ll never get there. What conditions do you want the subset to match? Work back from there.
- Curly braces mean a subset. If you see a pair in an MDX expression, what’s inside should be one.
- If the starting point is an element or dimension name, put it in its shipping container; the square brackets.[]
- Think of the period as “belongs to”. An element “belongs to” a dimension, children “belong to” a consolidation, etc.
- If there’s more than one item, separate by commas (or a colon, if it’s a range).
- Skim the Reference Guide to refamiliarise yourself with the key functions.
- You feed elements or subsets to a function inside its round brackets, you get elements or subsets back.
- When filtering by value, the element list also goes in brackets.
- Don’t be afraid to split the MDX onto separate lines to make it clearer.