santoshkanthety Skill: Run and Validate DAX
Trigger
Activate when the user wants to run a DAX query, test a DAX expression, validate syntax, explore model data via DAX, or aggregate values from the connected Power BI Desktop model.
Prerequisites
Must have an active connection — run pbi-agent connect first if DAX commands fail with "no connection".
Commands
# Run a DAX query (default table output)
pbi-agent dax query "EVALUATE TOPN(10, Sales)"
# Pick output format
pbi-agent dax query "EVALUATE VALUES('Product'[Category])" --format json
pbi-agent dax query "EVALUATE Sales" --format csv
# Constrain to a specific table context
pbi-agent dax query "CALCULATE(SUM(Sales[Amount]))" --table Sales
# Pin the SSAS port (skip auto-detect)
pbi-agent dax query "EVALUATE INFO.TABLES()" --port 56123
# Validate an expression without executing
pbi-agent dax validate "CALCULATE(SUM(Sales[Amount]), YEAR(Sales[Date])=2024)"
Shell Quoting Notes
Multi-line DAX (VAR / RETURN) passed as a shell argument loses line breaks and breaks parsing. For multi-line expressions:
- Prefer inline single-expression form:
DIVIDE([A] - [B], [B])instead ofVAR x = [A] VAR y = [B] RETURN ... - If VAR/RETURN is required, test the single-line collapsed form first (
VAR x = ... RETURN ...on one line — DAX accepts whitespace separators)
Common Exploration Patterns
# Inventory the model
pbi-agent dax query "EVALUATE INFO.TABLES()"
pbi-agent dax query "EVALUATE INFO.MEASURES()"
pbi-agent dax query "EVALUATE INFO.RELATIONSHIPS()"
# Preview a table
pbi-agent dax query "EVALUATE TOPN(10, Sales)"
# Row count
pbi-agent dax query "EVALUATE ROW(\"Count\", COUNTROWS(Sales))"
# Group-by aggregation
pbi-agent dax query "EVALUATE SUMMARIZECOLUMNS(Products[Category], \"Total\", SUM(Sales[Amount]))"
Common Failures
- "No active connection" → run
pbi-agent connect - Syntax error on VAR/RETURN → collapse to single-line DIVIDE / inline form, or test with
pbi-agent dax validatefirst - Table not found → run
pbi-agent model tablesto verify the exact name (case-sensitive)