This post is copy from http://gumper.com, a unique website coz it’s only have one item….
The basic script of Multi Dimensional Expression (MDX). It’s very usefull for developer to build some scenarios in a CUBE.
thank you,
hope it’s ok i copied all the page.

MDX Expressions

Function
Requires
Returns

CurrentMember
Dimension
Member

PrevMember
Member
Member

NextMember
Member
Member

Lag
Numeric Expression
Member

Lead
Numeric Expression
Member

ParallelPeriod
Level, numeric expression, member
Member

PeriodsToDate
Level, member
Set

YTD
Member
Set

MTD
Member
Set

Sum
Set, numeric expression
Number

 

Navigating the Hierarchy

Function
Requires
Returns

Parent
Member
Member

Children
Member
Set

FirstChild
Member
Member

LastChild
Member
Member

Descendants
Member, level [...]