MDX Calculated Members - Session-Scoped Calculated Members
Applies to: 
SQL Server Analysis Services 
Azure Analysis Services
Fabric/Power BI Premium
To create a calculated member that is available throughout a Multidimensional Expressions (MDX) session, you use the CREATE MEMBER statement. A calculated member that is created by using the CREATE MEMBER statement will not be removed until after the MDX session closes.
As discussed in this topic, the syntax of the CREATE MEMBER statement is straightforward and easy to use.
Note
For more information about calculated members, see Building Calculated Members in MDX (MDX).
CREATE MEMBER Syntax
Use the following syntax to add the CREATE MEMBER statement to the MDX statement:
CREATE [SESSION] MEMBER [<cube-name>.]<fully-qualified-member-name> AS <expression> [,<property-definition-list>]
<cube name> ::= CURRENTCUBE | <Cube Name>
<property-definition-list> ::= <property-definition>
| <property-definition>, <property-definition-list>
<property-definition> ::= <property-identifier> = <property-value>
<property-identifier> ::= VISIBLE | SOLVEORDER | SOLVE_ORDER | FORMAT_STRING | NON_EMPTY_BEHAVIOR <ole db member properties>
In the syntax for the CREATE MEMBER statement, the fully-qualified-member-name value is the fully qualified name of the calculated member. The fully qualified name includes the dimension or level to which the calculated member is associated. The expression value returns the value of the calculated member after the expression value has been evaluated,.
CREATE MEMBER Example
The following example uses the CREATE MEMBER statement to create the LastFourStores calculated member. This calculated member returns the sum of units sold for the last four stores, and will be available throughout the whole session of the cube.
Create Session Member [Store].[Measures].LastFourStores as
sum(([Stores].[ByLocation].Lag(3) :
[Stores].[ByLocation].NextMember), [Measures].[Units Sold])