Context & Filtering
DAX FILTER Function
Table iterator for complex conditions and multi-column constraints.
Syntax Definition:
FILTER( Table, FilterExpression )
Overview
FILTER iterates row-by-row over a table and returns a new virtual table containing only rows where the boolean expression is TRUE.
Architectural Deep Dive
Because FILTER is an iterator, it establishes a row context over its input table. It is frequently passed as a filter argument into CALCULATE when evaluating measures against column values or checking multiple interdependent columns.
Canonical Pattern Example:
High Value Sales =
CALCULATE(
[Total Revenue],
FILTER(Sales, Sales[Revenue] > 2500)
)Common Anti-Patterns & Mistakes to Avoid
- •Using FILTER(Table, ...) unnecessarily for simple column checks like Customers[Country] = 'USA', which hurts performance.
- •Forgetting to wrap with ALL() when intending to evaluate across the entire table.
- •Iterating over massive tables with millions of rows without pre-filtering.
Interactive Challenge
Put DAX FILTER Function into practice
Solve "High Value Transactions Filter" in our interactive Monaco editor with live dataset verification.