Filtered Value List

[musicarteca]

I a many to many relationship with three tables, students, courses and registration. A portal in the courses table enters the registred students for every course with the help of a student ID Value list.

I want to be able to filter the value list by the first letter of the last name, so I creat a calculation field that does this on the students table and a global key on the courses table. My pourpose is to base the VL on this relationship, but I am totaly stuck.

I am adding an attachment of the file

VL_filter.fp7.zip

[musicarteca]

No answer... Is this possible at all, or I am just totally lost?

[mz123]

I'm attaching the file again. Is this what you were aiming to do? Check the portal records that are coming up and check the drop-down list (I modified the relationship and the drop-down list)

I've had problems with making relationships with calculations so I used an auto-calc instead, with replacing.

If this is what you wanted and anyone knows a better way to do it, I'd love to hear it too, since I've run into this similar problem before.

VL_filter_Updated.fp7.zip

[Ender]

In your example, if you make the FirstLetter calc in Student a stored calc, you can use that for the relationship. Pretty much the same thing as using the auto-entered calc with replace.

[Søren Dyhr]

Using valuelists for ushering in values from a relation away, is only convenient when no fitering is required, the problem is that if the key value selects another set will previous selections change into the key value only, allthoug the option to avoid showing the actual key value would have been great if only they stayed as they were entered.

I would say that displaying valuelists not quite are up to it, when the lists a dynamicly defined, very much to our luck can we just use the tunneling feature to get the desired value shown, eventhough the only thing we wish to store in the join table is the keyvalue.

Next issue I think should be addressed is the derived key value which have to be stored and indexed when it's likely that the namefield is getting indexed eventually by a manual search, so we would end up with two redundant'ish indexes to find storage space for.

Why not put this on the other side of the relation where it easily could be a global value if we exploit a multicriteria relations definition?

By and large do I believe that the problem presented should be under script control as well as expoliting the modality we optained with the new window feature for GTRR.

Try to investigate these ideas in the attached template...

--sd

CourseRegistration.zip

[musicarteca]

Hi guys, thank you for the tips, but what I am looking for is not to filter the portal, but the value list itself. From the practical point of view, a user will enter the student ID from the VL, but instead of looking a list with 500 names he would filter it, while the portal always displays those studend already regitered in the course.

[Søren Dyhr]

From the practical point of view, a user will enter the student ID from the VL, but instead of looking a list with 500 names

I thought it was what I did in my template, where did I fail??

--sd

[musicarteca]

Thank you very much Søren, your solution works well, and I think I am going to go through that path, although I was trying to avoid scripting and find an relationshinp only alternative.

Edited April 10, 2006 by Guest

[Søren Dyhr]

Well you can actually but it will require two portals in the layout, although oneliners (scripts) aren't avoidable though.

Later when I thought about it, could the relation for picking be bolstered further with one more non-equi leg to prevent you from getting the same person entered twice. Simply by letting the scripting fill ValueListItems( over the portals content into a global more, or even let a recursive function gather the ID of the used into this third leg.

Remember if you go this way, that a pilcrow should always be in the field if the ValueListItems( calc is empty.

--sd

[musicarteca]

I would like to make an alternative question. Is this the regular procedure for a situation like this? lets forget for a moment the VL. What other approachs are common sense solutions to just entering the student IDs into a course list?

[Søren Dyhr]

I'm daft as a brush when it comes to common sense, common sense is anti-meritocratic, common sense favours activism etc.

I would say that your qustion is more rethoric than practical because there isn't an answer to it! While it instead could make sense to get different approches uploaded, recognizing that picking the right tool for the task ...is virtue, which is an entirely different matter than common sense or grasping a trend from a poll.

--sd

[musicarteca]

Good answerd sd, maybe you would care to share what some of those tools might be ...

[Søren Dyhr]

Well one of the approaches I've been using on occations is this:

http://www.dwdataconcepts.com/dl/tm/Many2Many.sit

Which is an old fm3-4 template you need to convert to fm8 by simultaneously dragging both of them above/over the filemaker app icon. Well some of the going ons inside isn't specific for this template, and that's the exclusion of the join table ...I grap it when ever it's posible.

But I would today exploit this custom function:

http://www.clevelandconsulting.com/support/viewtopic.php?t=637

--sd