DAX uses a syntax similar to Excel TableX [ColY] or [ColY] (fully qualified vs. not qualified) Cells cannot be referenced (like B23, B12:C15, …) DAX functions operate with table columns

Using DAX Calculated Columns

Using DAX Measures (or Calculated Field)

Sales Table [Amount] = [Qty] * [Price] [Unit Cost] = RELATED (Product [Cost]) [Total Cost] = [Qty] * [Unit Cost] [Margin] = [Amount] – [Total Cost] MarginPct = [Margin] / [Amount] Customer table [Sales] = SUMX (RELATEDTABLE(Sales), Sales[Amount])

Implicit Measures Automatically defined for all numeric columns Created measure “Sum of ” Can be changed to Avg, Count, Min, Max Explicit DAX Measures Gives a name to a DAX expression (formula) Can use complex expressions Interaction with Filter Context [Margin %] = SUM( [Margin] ) / SUM( [Amount] )

Row Context Similar to current row concept i.e. row of calculation for calculated column It gives a meaning to a column reference Evaluation of expression in aggregation function Filter Context Set of filters that defines “active” rows for each table Filters on single columns or on table rows Can be manipulated by using CALCULATE Every cell in a pivot table defines a filter context

RELATED( table[column] ) Follows relationship many-to-one Reads column value in the corresponding row of the related table RELATEDTABLE( table ) Follows relationship in both directions Returns a table containing corresponding rows in the related table Must be used as a parameter calling another function – i.e.: SUMX ( RELATEDTABLE(Sales), Sales[Amount])

Date and TimeInformationMath and TrigStatisticalText DATEISBLANKABSAVERAGECHAR DATEVALUEISERRORCEILING, ISO.CEILINGAVERAGEACODE DAYISLOGICALEXPCOUNTCONCATENATE EDATEISNONTEXTFACTCOUNTAEXACT EOMONTHISNUMBERFLOORCOUNTBLANKFIND HOURISTEXTINTMAXFIXED MINUTELNMAXALEFT MONTHLogicalLOGMINLEN NOWANDLOG10MINALOWER SECONDIFMODMID TIMEIFERRORMROUNDREPLACE TIMEVALUENOTPIREPT TODAYORPOWERRIGHT WEEKDAYFALSEQUOTIENTSEARCH WEEKNUMTRUERANDSUBSTITUTE YEARRANDBETWEENTRIM YEARFRACROUNDUPPER ROUNDDOWNVALUE ROUNDUP SIGN SQRT SUM SUMSQ TRUNC

Table Functions in DAX Differences between Excel and PowerPivot Excel doesn’t have functions returning a table Calculated Columns and Measures must return scalar values DAX includes functions returning a table Used as intermediate results passed as arg to other functions Often used for DAX aggregation functions (aggX) Differences from Excel

Table Functions in DAX Rows of related table following the relationship RELATEDTABLE (Table) Filter rows from Table according Condition (whenever that Boolean expression evaluates to true) FILTER (Table, Condition) Table made of a single column containing all the distinct (unique) values of a table column DISTINCT (Column) As DISTINCT, but also returns “unknown” (i.e. invalid relationships) VALUES (Column) Returns all data ignoring filter context and avoiding duplicates ALL (Table), ALL (Column) Returns rows from a table using filter context only for specified columns ALLEXCEPT (Table, Col1, Col2,..) Functions List

Functions that transform Filter Context CALCULATE ALL FILTER … Syntax samples Regular syntax (SalesAmt have to be an explicit measure) = [SalesAmt] / CALCULATE( [SalesAmt], ALL (Product) ) Shortened syntax =[SalesAmt] / [SalesAmt]( ALL(Product) )

Measures on Sales Table A measure can reference other explicit measures defined in DAX References to implicit measures require aggregation functions [Sales] = SUM ( Sales [Amount] ) [AllProd] = CALCULATE ([Sales], ALL(Product) ) = [Sales] ( ALL(Product) ) [Cost] = SUMX (Sales, [Qty] * [UnitCost]) [Margin]= [Sales] – [Cost] [Margin%]= [Margin] / [Sales]

DAX at work Weight Percent ABC / Pareto Time Period Comparison Customers / Products (distinct count) Many-to-many relationships

Regular CALCULATE syntaxShortened CALCULATE syntax AmountQuotaCustomers = SUM( Orders[Amount] ) / CALCULATE( SUM( Orders[Amount] ), ALL( Customers ) ) AmountQuotaProducts = SUM( Orders[Amount] ) / CALCULATE( SUM( Orders[Amount] ), ALL( Products ) ) OrdersAmount = SUM(Orders[Amount] ) AmountQuotaCustomers = OrdersAmount / OrdersAmount ( ALL( Customers ) ) AmountQuotaProducts = OrdersAmount / OrdersAmount ( ALL( Products ) )

ABC calculation requires calculated column Required attributes for pivot table axies, not measures Calculated Columns for ABC SalesAmount – Sales amount for product, customer, … Cumulated – Cumulated sales amount (descendent order) SortedWeigth – Cumulated Weight Percent (descendent order) ABC Class – A for 70%, B for 20%, C for 10%

ABC / Pareto SalesAmountProduct

ABC / Pareto CumulatedProduct

ABC / Pareto SortedWeightProduct

ABC / Pareto ABC Product

Time Period Comparison Date Table Create a table with dates (like a Date dimension) Use contiguous dates (no missing days) Fields for all required time aggregations (year, month, …) Year to Date – Cumulated value starting from first day of year DATESYTD changes filter context, TOTALYTD avoids CALCULATE Year-To-Date [Amount YTD] = CALCULATE( SUM( Orders[Amount] ), DATESYTD( Dates[Date] ) ) [Amount YTD 2] = TOTALYTD( SUM( Orders[Amount] ), Dates[Date] )

Time Period Comparison Corresponding value on previous year Use DATEADD to change filter context (SAMEPERIODLASTYEAR as alternative) Total value on previous year Use PARALLELPERIOD to get complete period (year) AmountTotPrevYear = CALCULATE( SUM( Orders[Amount] ), PARALLELPERIOD( Dates[Date], -1, YEAR ) ) Previous Year AmountPrevYear = CALCULATE( SUM( Orders[Amount] ), DATEADD( Dates[Date], -1, YEAR ) ) AmountPrevYear2 = CALCULATE( SUM( Orders[Amount] ), SAMEPERIODLASTYEAR( Dates[Date] ) )

Time Period Comparison Moving Annual Total (cumulated value of last 12 months) Use DATESBETWEEN to change filter context Amount 12M= CALCULATE( SUM( Orders[Amount] ), DATESBETWEEN( Dates[Date], NEXTDAY( SAMEPERIODLASTYEAR( LASTDATE( Dates[Date] ) ) ), LASTDATE( Dates[Date] ) ) ) Last 12 months

Number of Unique Customers / Products Distinct Count Measure

DAX syntax similar to Excel formulas Calculated Columns (PowerPivot tables) Measures (Excel pivot tables) Features available in DAX Excel functions (math, statistical, date/time, text, etc.) Aggregation of any expression over a table Table functions (FILTER, RELATEDTABLE, DISTINCT, ecc.) Fetch data across relationships (one-many, many-one) Set or modify evaluation context (ALL, CALCULATE, ecc.) Time Intelligence functions

BIU302 – Enriching Microsoft PowerPivot for Microsoft Excel Applications Using DAX Thursday, June 10 | 9:45 AM - 11:00 AM | Rm 244