Newbie - tutorial contradictions

[The_Crofter]

Hi,

Just trying to get my head round relationships, have purchased the missing manual, read the white paper and looked at the FM8.5 tutorial.

The missing manual is quite specific regarding the use of many to many relationships and suggests that you always use a link table. Curiously the white paper & FM8.5 tutorial both show examples of tables that are linked by many to many relationships.

Is there ever a situation when joing two tables together by this method is correct ?.

I have a feeling I will be spending a lot of time on these forums !

Cheers

[Søren Dyhr]

I do not consider this a contradiction, but an advice - for starters to include the table for the linking purpose.

But a lot of times where the statistics on the join tables are considered irrelevant, could the dedicated table be avoided. If say you're in situation where you need an appointment to show up several time with som interval, here could the many 2 many structure instead be made by either a pilcrow delimited list or a repeating calc'field.

The benefit from the "cheating" approach is that a calc'field be it a repeating field or made via a custom function change the linking much much faster than deletion of earlier join records and the creation of new ones, and kind of circumvent the lack of event triggers in filemaker.

--sd

[comment]

Another way to look at this is to ask if the join table represents an entity in your solution. For example, many people can have many types of credit cards. The fact that one of my customers has been issued another card is a non-event as far as I am concerned - so it's entirely sufficient for me to add a check for VISA in the customer's record.

The situation is entirely different if I am the one issuing/cancelling the cards.

[bcooney]

I could be totally wrong here, but could the OP be misinterpreting a multi-criteria relationship with a many-to-many relationship?