CALCULATE & Filter Context Filter context override
Wrap an aggregation in CALCULATE and give it filter arguments. Each argument replaces whatever filter already exists on that column — it doesn't add to it.
Time Intelligence Shift the date filter
Every time-intelligence function works the same way: it takes the current filter on your date column and moves or stretches it. The measure underneath never changes.
Relationships & Filter Flow One side filters the many side
In a star schema, filters flow from the "one" side of a relationship down to the "many" side by default. Cardinality and cross-filter direction decide who can filter whom.
Iterator (X) Functions Row context, then aggregate
Every X-function walks a table one row at a time, evaluates an expression in that row's context, then rolls all the row results up with a single aggregation.
Common DAX Patterns % of total · running total · rank
Three patterns you'll write in almost every report, all built from the same idea: temporarily clear a filter with ALL(), then rebuild it exactly the way you want.