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Hi Bill,
So, let me make sure I understand. I'm going to assume that this is just for documentation purposes? I'm not sure why you wouldn't just use an XML tool, but if you're looking for ways to "fool" ERwin, you can certainly set up your own "methodology". I do all sorts of wacky things in ERwin just for the sake of documentation.
I guess you have a couple of workarounds, but again, this would only be to document what you're trying to do. So, I did a quick sample model and tried a couple of things:
1) In the logical view, I included only include the atomic attributes. In the physical view, I added Person_name and marked it physical only so it wouldn't show in the "logical", i.e., fully normalized view. I selected it in the graphic window and put it in italics (this would just be my own way of showing which columns were "groups".) Then it's comment would indicate that it is a group consisting of Given_name + Surname + Middle_name. But on the physical "table" in the graphic, you'd still see all 4 columns and no way to quickly realize what goes inside of what.
2) I suppose if you wanted to "see" it in the physical, I tried this:
Kept Person_name in the Person table, then created a "dummy" table called "Person_name" and moved the 3 component columns to that new "entity" and related the two with a 1:1. It's pretty hokey but would show that those 3 columns belong to Person_name - and show them in sequence. I guess you might be able to show any leveled hierarchy that way as well, i.e., a single chain of 1:1, each parent table is a group that contains all the components. If a component is itself a group, you'd have another 1:1 to show its contents, and so on and so on. (But still, really hokey).
So, for example, say you have another group for Person called Person_address (assume only 1 per Person) which itself is a complex data type. Then you'd hang *another* entity in a 1:1 off Person, call it Person_address. It contains say, Street_address (complex type), and City, State, ZIP. Then, to show contents of Street_address, hang another 1:1 off Person_address and it would contain say Street_number and Street_name.
Not sure it would work but from what I understand about XML, seems like a lot of it is a simply outline that could be shown as a series of parent/child entities. It would get pretty large...
2) Another way would be to create a UDP for the "XML parent group" or something like that. And put Person_name in the UPD for each of the components. Not sure that would work for leveled groups.
so,this took me all of about 5 minutes so I haven't given it much thought. Try it and see if it works.
But remember, I'm talking about *documentation only* here - please don't misinterpret my thought process.
Regards,
anne
Bill Lewis <datamodel@xxxxxxx> wrote:
Has anyone successfully modeled a "complex data type" in ERwin? For
example, a group-level column (I know, Dr. Codd would not like it)
such as can be implemented in XML or, er, COBOL...such as Person_name
(Given_name, Surname, Middle_name)??
Thanks,
Bill L
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