sql server - ON COLUMNS compared to ON ROWS -

Why MDX is OK to do this:

   
 but  not  is the following:  
 [code] SELECT [MyDim]. [MyHeer] [MyLevel] From [CubeName] to [RUB]   
 
 
 Not found ;-) On the columns, the rows are defining the 'shape' of the result (the tuples are exactly the same) and it has been determined that the column is only fine but not only on the rows; I.e.:  
  a | B C1 | 2 | 3   
 but not:  
  a | 1b 2c | 3   
 As a stranger, I have no problem recalling those values ​​from an MDX server implementation point of view. By the way, no columns and no line are valid:  
  Choose from [cube]