Counting blank values from left join

[zagzebski]

I want to count fields that do not have a join back to the main table. For instance in the table below if I left joined to Table 2 from Table 1.  How do I count the two effective dates (Product D and F) that had no corresponding join to the main table (Table 1). Is this possible?

Example

Product(Table 1)  Zone(Table 1)  Product (Table 2)  Effective Date (Table2)

     A                       North                 A                        12/31/2012

     B                       South                B                         1/31/2011

     C                       East                  C                          9/27/2010

     D                       West                 -                                -

     E                       North                 E                          8/21/2012

     F                       East                  -                                 -    

[Anonymous]

Possible, with set analysis.  I guess you count Product which doesn't have Effective Date.
Something like this:
count({<[Effective Date]-={*}>} Product)

Regards,
Michael

[zagzebski]

Thanks for the response.

Unfortunately it just returns a 0. Any thoughts?

[Anonymous · Accepted solution]

OK, try this:

count({<[Effective Date]=> - <[Effective Date]={*}>} Product)

[zagzebski]

Awesome- it worked!

Not exactly sure how it works though - do you have a brief description on this set analysis so I can use for future reference.

[Anonymous]

No secrets, it is all in "help" 🙂

(Plus spending time on top of that...)

[zagzebski]

Thanks - I hadn't seen it in help before I will try to track down.