If you run the following MDX:
SELECT [Customer].[Customer].[Aaron Adams] ON 0
FROM [Adventure Works]
You will get the result:
Aaron Adams
4
What's the number '4' for?
It's not the key for Aaron Adams, it does not mean 4 Aaron Adams either. It indicates that Aaron Adams has 4 entries in the FactInternetSales table in the cube.
Run the following queries in SSMS:
-- Return the key 28866 for Aaron Adams
SELECT *
FROM [dbo].[DimCustomer]
WHERE FirstName = 'Aaron' AND LastName = 'Adams'
/*
Return 4 rows for Aaron Adams in the FactInternetSales table. He ordered 4 different products on a single order - order number: SO56918
ProductKey OrderDateKey CustomerKey SalesOrderNumber SalesOrderLineNumber
529 20071030 28866 SO56918 1
539 20071030 28866 SO56918 2
214 20071030 28866 SO56918 3
489 20071030 28866 SO56918 4
*/
SELECT ProductKey, OrderDateKey, CustomerKey, SalesOrderNumber, SalesOrderLineNumber
FROM [dbo].[FactInternetSales]
WHERE CustomerKey=28866
