Querying Your Cube - Getting Started with SQL Server 2012 Cube Development - page 125

When you define a tuple, you have to make sure that you do not add members that
are exclusive; the query below is an example of this:
--Query 5.11
SELECT [Measures].[Sales Amount] ON 0,
([Product].[Product Hierarchy].[Product
Category].&[1],
[Product].[Product Line Hierarchy].[Model
Name].&[Chain]) ON 1
FROM [Adventure Works DW2012];
In this case, it is specified that the product category is [Bikes] , but the product line
is [Chain] ; in the cube, such a product does not exist. In this case, you get a result
that is just null.
Note
You cannot reference a dimension hierarchy several times in a tuple; like in the
following query:
--Query 5.12
SELECT [Measures].[Sales Amount] ON 0,
([Product].[Product Hierarchy].[Product
Category].&[1],
[Product].[Product Hierarchy].[Product
Category].&[3]) ON 1
FROM [Adventure Works DW2012];
In this case you will get the following error:
Query (2, 1) The 'Product Hierarchy'
hierarchy appears more than once in the
tuple.