Hello, I am an MSc student at University College London, and as part of a project I am currently working on, I am keen find out what users of the UML for OO ...
Clare Gryce
ucabacg@...
Aug 1, 2002 2:23 pm
1247
Hi, I have a seemingly simple problem to model but I can't get the ORM specified in a way so that Visio would actually implement the ER the way I expect it to....
Wolfgang Baeck
wbaeck@...
Aug 3, 2002 9:43 pm
1248
Wolfgang, This should work, but here are some things to look at: 1) Is the internal uniqueness constraint on the Fact Rate is for Item on the Rate role (rate...
Hi Wolfgang, ... You want to use and external uniqueness constraint in order to "co-reference" the identification scheme of Rate. Enter the following facts in...
Scot A. Becker
scot@...
Aug 5, 2002 3:36 pm
1250
Wolfgang: From an ER side of the picture you lack a specfic foreign key into RATE from ITEM. ALL er diagram tools will give you the same problem. I.E. there...
... From: Don [mailto:dkretz@...] Sent: Sunday, August 04, 2002 12:02 AM To: jcm-owner@yahoogroups.com Subject: Re: ItemRate Model This usually works...
trishs
trishs@...
Aug 5, 2002 3:42 pm
1252
Interesting how Wolfgang's problems stem from an incomplete specification of the semantics of the situation. Those responding to his posting must make...
geverest@...
Aug 5, 2002 4:52 pm
1253
I agree with everything that has been said on this subject, yet my problem isn't table think but familiarity with ORM in some intricate issues. The experienced...
Wolfgang Baeck
wbaeck@...
Aug 5, 2002 6:41 pm
1254
Don, Thank you for your very detailed response. Perhaps you have seen on my earlier post that I found the solution but I'm dissatisfied with the approach I...
Wolfgang Baeck
wbaeck@...
Aug 5, 2002 7:57 pm
1255
Scot, I liked your response very much since it didn't necessitate the creation of an objectified fact which in my opinion is created too often because the ...
Wolfgang Baeck
wbaeck@...
Aug 5, 2002 7:57 pm
1256
Hi Wolfgang, This error message is correct; I had assumed the UC on the Item has Rate fact was only spanning the Rate role. Sorry for the confusion. It looks ...
Scot A. Becker
scot@...
Aug 5, 2002 9:33 pm
1257
Hello Wolfgang and Scott, I took some liberties with the model: got the following output on a build Starting Build... ...\VISIO\IRDB.VSD : Updating existing...
Hughan Ross
hughan.ross@...
Aug 5, 2002 11:27 pm
1258
MessageScot, To bad that I can't make that version of the model work. It is particularly attractive since it is so intuitive for the domain expert. More so...
Wolfgang Baeck
wbaeck@...
Aug 6, 2002 3:14 am
1259
Woops, I have gone off half-cocked - add 'primarily identified by' to the uniqueness constraint and forego the warning on the build. For each Item i and...
Hughan Ross
hughan.ross@...
Aug 6, 2002 3:15 am
1260
Hughan, Bingo! That is intuitive and results in what I would expect. Now I see why my attempt didn't work since I had the constraint on the Item has Rate fact ...
Wolfgang Baeck
wbaeck@...
Aug 6, 2002 3:15 am
1261
I think I need to clarify - we are more in agreement than you think, perhaps. ... I said: I'm going to start out the wrong way for a while. and you caught it. ...
Eaglewms
dkretz@...
Aug 6, 2002 3:16 am
1262
Wolfgang, I agree with you completely. I always tell my students to carefully review the tables generated by the ORM modeling tool, and if it doesn't come out...
geverest@...
Aug 6, 2002 3:16 am
1263
Thrishs, Thank you for your very detailed response. Perhaps you have seen on my earlier post that I found the solution but I'm dissatisfied with the approach I...
Wolfgang Baeck
wbaeck@...
Aug 6, 2002 3:27 am
1264
Good, we are in full agreement here! (Does that make us right? ;-)) I just got reminded of another table creation bug in Visio. In our example of Item and...
Wolfgang Baeck
wbaeck@...
Aug 6, 2002 4:11 am
1265
Wolfgang, Here is how I specified the problem (as I understood it) in ORM. Surely there are other ways. Object Type #1: Item; entity type; identified by...
David, See my responses in between. Wolfgang ... From: Cuyler, David S [mailto:dscuyle@...] Sent: Tuesday, August 06, 2002 10:18 AM To:...
Wolfgang Baeck
wbaeck@...
Aug 6, 2002 4:33 pm
1267
I have some questions left. First, the Item Entity. It seems to me we're pulling a fast one by using an Identity column as a Reference Scheme. To me, an RS is...
A little polishing, and again, this has been tested in Visio with no objections whatever. In practice, when modeling, I like to break the "megadiagrams" into...
Fascinating discussion! While both solutions work well for these facts, I wonder where you go from here. As you add information, some of which does and some of...
Hi, Sorry for taking a bit to reply. I like your redux very much! First, back to your previous post. Aside from the fact that I intentionally hid most of the...
Wolfgang Baeck
wbaeck@...
Aug 7, 2002 2:41 pm
1271
Good thoughful feedback - I'll add some notes - This has been a great exercise for me, too, because it has exposed some the reasons that I use VisioORM (what...
Overall, this discussion has provided more insight to me than the short moments when I get input from my domain experts. The situation is this, I'm creating a...
Wolfgang Baeck
wbaeck@...
Aug 7, 2002 9:01 pm
1273
Hello All, Does anyone know if there is any effort ("implementation") for generating XML-Schema/DTD from ORM schema? e.g. Implementation of "ORM and...
Wolfgang, That is a bug in the product, but it's not as bad as you might expect, because the incorrect identity settings are automatically removed at the DDL...
Terry Halpin
TerryHa@...
Aug 12, 2002 9:24 pm
1275
Terry, Thank you very much for clearing that up. That helps a lot. Another sore point is the migration when you change the ER model, let's say a column ended...
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