Thanks Ted, Pretty much as I expected in that we do indeed have an "added feature" of the DBMS relationship in live cursors when using VFP which is handled in na different way !!
As I'm converting (slowly) the existing native VFP table onto MySQL this requirement to model the "extended FK" will eventually become redundant and as you say I'll order the cursors using the additional "order by" in the SQL statement. It's just that I wanted a simple way to model the existing tables but not to worry as I can always include the foreigh FK expression in the relationship description label. I must admit I'm very impressed with XCase so far even though I haven't yet looked into the scripting features and as you say, the diagrams do look very pretty especially as I need to introduce a junior person to the existing system schema in as painless a way as possible. As I said, I have taken a look at Enterprise Architect which seems to be a "monster" with loads more facilities than I need at present so I think I'll at least start with XCase. Thanks for the input and your comments are much appreciated. Dave Crozier -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ted Roche Sent: 19 March 2007 12:33 To: [email protected] Subject: Re: Playing with UML On 3/19/07, Dave Crozier <[EMAIL PROTECTED]> wrote: > > Now, my question. Using standard UML how do you represent this relationship? Well, I don't think that you can, or should. The relationship is between the PK and the FK, two identical fields. If you're not joining the tables this way, you're not using a relational database technique, won't be able to take advantage of Rushmore and will run into scaling issues. The relationship needs to be between identically-defined fields of the same type and scale. The *ordering* of the data in the relationship can easily be expressed with an ORDER BY clause when you're deriving a cursor. > Questions: > 1. Is the ability to link tables in this way only catered for in UML by > linking the PK of the Customer and the PK_Customer fields and then doing a > sort in the SQL Select statement as in client/server? I would say not "in UML" but rather "in DBMS." UML just limits your ability to express inappropriate relationships. > 2. How do others in the group document their database table relationships? All the time. xCase isn't just my documentation tool, it's my primary means of modeling new changes to the database, scripting the changes, and ensuring synchrony between the model and the live data. And it prints pretty diagrams that impress the clients, too! -- Ted Roche Ted Roche & Associates, LLC http://www.tedroche.com [excessive quoting removed by server] _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
