Linking records among tables

[bluearrow]

Hi,

In FM6, I used to have a LINK field in every table defined as numeric field, autoenter value 1. This field allowed me to link every record in file 1 to every record in file 2. It was very useful.

However, in FM7+ relationships have changes. Now, if I want to link all records in one table to all records in another table I have the option to select the cartesian operator (X) and just chose any field in table 1 and any field in table 2 (as far as I understand it, the fields itself are irrelevant as long as they are not global fields).

Is this correct? Can I forget about the LINK field? Does the cartesian relationship actually ascts as a replacement for this kind of relationships present in FM6 and prior?

Thanks

[mr_vodka]

Yes for the most part, you can use the Cartesian join to replace it. There are some times when usinga constant comes in handy, but only when trying to get creative.

[bluearrow]

Thank you Mr. Vodka.

I can understand that there might be situations where using a constant might be a better option but:

Can I connect any field in table 1 to any field in table 2? Are there any considerations I should take into account?

For instance, one consequence of this is that if I choose any field and I am not consistent among tables for this type of relationship, I might end up deleting or changing a field that I use in a cartesian relationship. This could never happen if I create a specific field for linking the tables. But then, if I create the specific field and use it, I return to the same situation I have back in FM6.javascript:void(0)

crazy

[comment]

I might end up deleting or changing a field that I use in a cartesian relationship.

The relationship will keep on working, even if you delete the "key" fields (which are not doing anything in a 'Cartesian product' relationship).

Anyway, I think it's good practice to use the primary key of each table for this type of relationship. Surely, you won't be deleting those.

[bluearrow]

Thank you.

Perfectly understood now. I will indeed use key fields for cartesian relatioships. I wonder why this type of relationship is not implicit in FileMaker, taking into account that choosing fields in either table is just a formality required by FileMaker...

Regards