value exists in portal / related found set

[Gabe]

I just need a quick way to determine if a specific value exists within a related found set of records.

[aaa]

Let you have two tables:Customers and invoices which joined by Customer_Id. In the invoices you want to know: are there any Invoice_Number for giving Customer. In customer table create global_field where you will put searching Invoice number for curent customer. Create new_relation from Customer to Invoices by Customer_Id and global_field=invoice_number. Now in customer create calculating_field=Count(new_relation::Invoice_number). It seems this must work. If not i will create example. I am sorry if i am not clear.

Edited December 22, 2005 by Guest

[Gabe]

Thanks, but that only shows if there are any related values.

I want to know if there is a specific value existing within a set of related records, most of which may not contain the value I am looking for.

For example:

I have tables: Team, League, and Participant.

then I have a join table: participant_in_team

There is a list of leagues. Then there is a list of teams, and each team is assigned to a single league. I add participants to the teams, and particpants may be in more than a single team, but not in more than one team in the same league.

So I have:

League1->participant_in_team->team->League2

Now if I am within the context of League1, I have a global variable containing the id of a given participant which points to participant_in_team, so that I can put a portal on the layout for League1 and it will show from League2 which leagues the participant is already a part of.

What I want is to be able to look at League2 whenever the user wants to add the given participant to a new team. If the currently selected league id or name is within the records in League2, then the user cannot add the participant to the team.

It's simple, but I can't figure out how to simply do a quick check to see if a specific value exists in the found set of a related table.

[Gabe]

All I need is to know:

does value X exist within the set of related records.

that's all.