3 Entities Relationship (Newbie)

[amigos]

I have 3 Entities: ENTRY, BOOK and DOCUMENT.

The ENTRY can only have one type: BOOK or DOCUMENT.

How can I achive it. I created the relationships, Primary and Forein keys, but it does not work the way I want.I did try to validate with no results, besides the ugly dialog box pops up!

Please see an attachment ( I left a very few attributes to keep database clear.) and help me or at least point me what should I do.

note:

The structure of tables must be preserved because there will be a huge data imported from a PostgreSQL.

Thank you very much!

ENTRIES.fp7.zip

[LaRetta]

You have it backwards. You should not have an fk_entryID in Books and Documents. You need an EntryType and bookID or documentID field in Entries which will contain the book or document primary key. Can an entry be both a book and a document? If so, you will want either a Type field in Entries and then two fields (one for bookID and one for documentID) ... or you will want a join table.

The ENTRY can only have one type: BOOK or DOCUMENT.

In general, your Entry table is your 'many' side, pulling in only ONE ID from either book or document. But you also don't need both a book and document table. You can share the same table and just include a SourceType field (see attached). Sometimes you NEED to split tables but I do not believe you need to do it here.

But your split of data still seems a bit off ... your Source (Library) should contain your book titles or document titles as well (I think). Anyway, I didn't do anything with this portion, only your book/document table.

LaRetta

ENTRIESrev.zip

Edited March 16, 2009 by Guest

[amigos]

You see DOCUMENT, BOOK (there are more not in a sample) are all subsets of ENTRY.

If I do your way a cohesiveness will be lost, and that's what I do not want.

I am posting a data model of that database to give you idea how it looks in PostgreSQL,

it's not finished as I'm in progress of drawing, but the main thing is there, so you should be able to get a clear picture.

FileMaker is very friendly, but I must tell you that tables and relationships are very confusing.

I guess I must get some book and study those proprietaries of FileMaker.

Thank you very much for your time.

ENTRIES-Model.pdf.zip