possible to ensure a unique, related field

[trickyslip]

Quick question: I will use the analogy of a book, with chapters. I have two tables, one called books, one called chapters. Each record in the books table is a book, and each record in the chapters table is a chapter in a specific book. I want to make sure that there is never more then one chapter with the same name in any given book, but that different books could have the same chapter name, for example:

Book 1: "A bedtime story"

Chapter 1: Introduction

Chapter 2: The End

Book 2: "A work story"

Chapter 1: Introduction

Chapter 2: The middle

Chapter 3: The end

So far so good. I want to make sure that this entry can not be made in either book:

Chapter 4: Introduction

I am creating the chapter records by using a portal that reverences a relationship between a unique id between chapters and books, the layout is set to "books" and the portal creates records in the chapters table.

What I have done is made a calculation field which is ::Book Name & Chapter Name, so in this case would be "Book1Introduction" - can I make sure that is unique? Ie, during data entry, can I make sure that a calculated value which is the result of a related field and a field on the current layout is unique?

[David Jondreau]

What I have done is made a calculation field which is ::Book Name & Chapter Name, so in this case would be "Book1Introduction" - can I make sure that is unique? Ie, during data entry, can I make sure that a calculated value which is the result of a related field and a field on the current layout is unique?

You can't validate a calculation, but you can validate a Text field with an auto-enter calculation.

[trickyslip]

That worked great, thank you very much. :