Understanding Relationships - Multipul relationshi

[radiodan]

Hello,

I am trying to understand relationships in more detail, as I have run up against a problem.

I have uploaded a simple example.

I have Clients, who are related to jobs (of two types hardware and software). I then have employees. To assign an employee to a job, I use a join table with a referance. Say "First Job of the Day", I then take the jobID and the employeeID and put the two togethin ini the Join table.

This works fine for Hardware but when I try to put the relationship in for Software (see example) Filemaker says "there cannot be more than one relational path...." and tried to put in another table.

How do I get around this. You can see the reason for the realtionship being like this in the two portals (one of which works!) in Employees where I want to be able to see what employees are doing.

Any help very much appreciated

Daniel

SoftwareHardware.zip

Edited January 13, 2006 by Guest

[stanley]

Daniel:

FileMaker isn't telling you to create a new table, but rather a new "table occurance." This is so that you don't create circular relations, which is what you are trying to tell FM to do. Just imagine if you were able to connect your SoftwareBooking table occurance ("TO") to your Employees TO. Your relationship graph would be a big circle, and Employees would, through the circle, relate to itself. No good.

You should add another TO for Employees and connect that to Software. Then, in your portal for that data, make sure you select that relationship, and it will work fine.

It can take a bit of getting used to, but once you've got the hang of the relationship graph and table occurances, you'll see what a great way it is to represent the relationships, and how clearly it shows what is happening.

-Stanley

[Ender]

You can't have loops in the relationship graph. Instead, use additional copies of the needed table occurences. In the attached example, you might use one table occurence group to access things from the Client perspective, and the other table occurence group to access things from the Employee perspective.

You will need to modify some of your layouts' and fields' source tables to reflect this change of context.

SoftwareHardware2.fp7.zip

[stanley]

Actually, I got that backward in your specific case. Enclosed is a modified version of your file. Note that the fields in the Software Booking 2 portal have also been changed to the new relationship ("Sofware Booking 2").

-Stanley

SoftwareHardware.fp7.zip

[radiodan]

Thanks for the advise that makes things a bit clearer.

What should I be thinking about when I make these relationships, just that it works, or does it take a bit more planning? Would it for example make any differance if related employees directley to the SoftwareBooking and HardwareBooking, and had a double occurance of the SoftwareJobs?

Can I just think about how I need tables to relate and leave Filemaker to make multipul occurances of the table if needed?

[Søren Dyhr]

Can I just think about how I need tables to relate and leave Filemaker to make multipul occurances of the table if needed?

No it's your task! - watch this movie called "Graph Rules - Four rules to remember"

http://previews.filemakermagazine.com/videos/541/GraphRules_full.mov

--sd

[Scottish]

SD

THANK YOU!

Scottish

[radiodan]

Ok I have watched the video, which again helps. I still can't find any rule as to where double table occurances are prefferable, and work out if they reduce functionality in any way. i.e why not just let filemaker add them without a second thought if needed?

Would it for example make any differance if I related employees directley to the SoftwareBooking and HardwareBooking, and had a double occurance of the SoftwareJobs?Ok I have watched the video, which again helps. I still can't find any rule as to where double table occurances are preferable, and work out if they reduce functionality in any way. i.e why not just let filemaker add them without a second thought if needed?

Would it for example make any difference if I related employees directly to the SoftwareBooking and HardwareBooking, and had a double occurance of the SoftwareJobs?

Edited January 17, 2006 by Guest