Constant selection in query (Apples and Oranges)

Added From Sven van Leuken’s Blog

The great thing about an infoset is that it can combine data from different sources via a "JOIN" (inner/outer) mechanism. This may come in very handy if you want to report on two different sources (apples & oranges) without having to show the annoying '#'.
But what to do if you want to show data from the Apples bucket, even though this bucket is empty for the corresponding Oranges bucket? (and vice versa)
Eg.
Apples: 10 pieces in January 2010 for customer A
Oranges: 5 pieces in January 2010 for customer B
With an infoset (JOIN) on Apples & Oranges (where Apples is 'leading') it is impossible to show the Oranges of January for customer B because Apples has no customer B entry.
To be able to show the Oranges data, you have to use a multiprovider which uses the UNION mechanism. The downside of the multiprovider is that it will show a # for January Oranges for Customer A and a # for January Apples for Customer B.
This unwanted # behaviour can be overruled by using constant selection
Step 1: Create restricted keyfigure

Step 2: Tick on constant selection

Without constant selection:
January 2010;Customer A; Apples 10; Oranges #
January 2010;Customer B; Apples #; Oranges 5
With constant selection:
January 2010;Customer A; Apples 10; Oranges 5
January 2010;Customer B; Apples 10; Oranges 5