MDX Functions

About 600 wordsAbout 2 min

2026-09-01

MDX (Multidimensional Expressions) is a powerful query language designed for multidimensional data analysis, commonly utilized in OLAP (Online Analytical Processing) systems. Datafor leverages MDX to define calculated metrics and perform multidimensional data operations such as querying, aggregating, filtering, and computing.

This guide provides an overview of essential MDX functions grouped by their common use cases:

Function Categories

Aggregation Functions: Calculate summaries such as totals, averages, and counts.
Set Functions: Operate on sets to combine, intersect, filter, or sort data.
Member Functions: Access and manipulate hierarchical dimension members.
Time Functions: Perform calculations and conversions related to dates and time.
Logical Functions: Apply logical conditions to data.
String Functions: Manipulate and format textual data.
Mathematical Functions: Execute numeric calculations.
Type Conversion Functions: Convert data from one type to another.

Aggregation Functions

Function	Description	Syntax	Example
COUNT	Counts members or elements in a set	`COUNT(Set)`	`COUNT({[Measures].[Sales]})`
SUM	Calculates the sum of set elements	`SUM(Set)`	`SUM({[Measures].[Sales]})`
AVG	Calculates the average of set elements	`AVG(Set)`	`AVG({[Measures].[Sales]})`
MIN	Finds the minimum value within a set	`MIN(Set)`	`MIN({[Measures].[Sales]})`
MAX	Finds the maximum value within a set	`MAX(Set)`	`MAX({[Measures].[Sales]})`
DISTINCTCOUNT	Counts distinct members within a set	`DISTINCTCOUNT(Set)`	`DISTINCTCOUNT({[Customers].Members})`
AGGREGATE	Aggregates values based on set members	`AGGREGATE(Set)`	`AGGREGATE({[Time].[Q1], [Time].[Q2]})`

Set Functions

Function	Description	Syntax	Example
FILTER	Filters set based on a condition	`FILTER(Set, Condition)`	`FILTER({[Customers].Members}, [Sales]>1000)`
NONEMPTY	Retrieves non-empty intersections	`NONEMPTY(Set)`	`NONEMPTY({[Customers]} * {[Time].[Q1]})`
ORDER	Orders members by a criterion	`ORDER(Set, Expression, ASC	DESC)`
UNION	Combines two sets into one	`UNION(Set1, Set2)`	`UNION({[USA].[CA]}, {[USA].[WA]})`
INTERSECT	Intersection of two sets	`INTERSECT(Set1, Set2)`	`INTERSECT({[USA]}, {[USA].[WA]})`
EXCEPT	Difference between two sets	`EXCEPT(Set1, Set2)`	`EXCEPT({[USA]}, {[USA].[WA]})`
DISTINCT	Removes duplicate members from a set	`DISTINCT(Set)`	`DISTINCT({[Customers].Members})`
CROSSJOIN	Cartesian product of sets	`CROSSJOIN(Set1, Set2)`	`CROSSJOIN({[USA]}, {[Products]})`

Member Functions

Function	Description	Syntax	Example
CURRENTMEMBER	Current context member	`CURRENTMEMBER`	`[Customers].[USA].[CA].CURRENTMEMBER`
PARENT	Parent of a member	`PARENT(Member)`	`PARENT([Customers].[USA].[CA])`
CHILDREN	Children members	`CHILDREN(Member)`	`CHILDREN([Time].[Q1])`
SIBLINGS	Sibling members	`SIBLINGS(Member)`	`SIBLINGS([Customers].[CA])`

Time Functions

Function	Description	Syntax	Example
NOW	Current timestamp	`NOW`	`NOW`
DATEADD	Adds intervals to a date	`DATEADD(Interval, Date)`	`DATEADD("YY",1,[Time].[Q1])`
DATEDIFF	Calculates difference between dates	`DATEDIFF(Interval, Date1, Date2)`	`DATEDIFF("YY",[1997],[1998])`

Logical Functions

Function	Description	Syntax	Example
IIF	Conditional expression	`IIF(Condition,TrueValue,FalseValue)`	`IIF([Sales]>5000,"High","Low")`
AND	Logical AND operation	`AND(Condition1,Condition2)`	`AND([Sales]>5000,[Time].[Q1])`
OR	Logical OR operation	`OR(Condition1,Condition2)`	`OR([Sales]>5000,[Time].[Q1])`

String Functions

Function	Description	Syntax	Example
CONCAT	Joins two strings	`CONCAT(String1,String2)`	`CONCAT("Hello"," World")`
REPLACE	Replaces substring	`REPLACE(String,Old,New)`	`REPLACE("Hello World","World","MDX")`

Mathematical Functions

Function	Description	Syntax	Example
ABS	Absolute value	`ABS(Number)`	`ABS(-10)`
ROUND	Rounds number	`ROUND(Number,Digits)`	`ROUND(3.14159,2)`

Type Conversion

Function	Description	Syntax	Example
CSTR	Converts to string	`CSTR(Value)`	`CSTR(123)`
CINT	Converts to integer	`CINT(Value)`	`CINT("123")`
CDATE	Converts to date	`CDATE(Value)`	`CDATE("01/01/2020")`

MDX functions are essential for effective data analysis in Datafor, providing flexibility and powerful tools to interact with multidimensional data. Use this guide as a quick reference when building advanced analytical models and reports.