Yue-Hwa,
You are right with all three statements. Let me explore it a little bit more below... Regards, Davor Gornik -----Original Message----- From: Chang_Y [mailto:[EMAIL PROTECTED]] Sent: Wednesday, May 29, 2002 2:31 PM To: '[EMAIL PROTECTED]' Cc: Chang_Y Subject: (ROSE) rational rose data modeler questions I have been using rational rose data modeler to create "logical ERD" in object model. Questions: 1. Can the object model display the "key" (i.e. Part of Object Identity) field? (I know it can be displayed in data model.) [Gornik, Davor] You are right: we can not display it on the diagram. Often I use a stereotype to display it - for example <<Identifier>> 2. I have been using Association for non-identifying relationship and Aggregation by Value for identifying relationship. Is this correct? Does it cover all the relationships in data model? [Gornik, Davor] This is one of the possibilities. The logical model in UML is richer and contains not only aggregation and association. For example you could use subtyping (inheritance) instead of aggregation. All of these really depend on the kind of relationships between objects. The logical model should use "natural" relationships, the physical model is constrained by the database. 3. For Association relationship, I should not add "foreign key" in the related Class because when transforming to data model, the foreign key will be added automatically. e.g. INDUSTRY Class attributes: Industry_Code (key), Industry_Title ITEM Class attributes: Item_Code (key), Item_Price And one INDUSTRY maps to many ITEM; Industry_Code will be added to ITEM class as foreign key in data model. [Gornik, Davor] Yes, you are right again. The association itself contains the key definition. The physical implementation of the database will define what constraint to use and depends on the physical implementation and not only on the logical relationship. Also, I'd appreciate it if you have other valuable experiences about the tool to share. Thanks. Yue-Hwa ************************************************************************ * Rose Forum is a public venue for ideas and discussions. * For technical support, visit http://www.rational.com/support * * Post or Reply to: [EMAIL PROTECTED] * Subscription Requests: [EMAIL PROTECTED] * Archive of messages: * http://www.rational.com/support/usergroups/rose/rose_forum.jsp * Other Requests: [EMAIL PROTECTED] * * To unsubscribe from the list, please send email * To: [EMAIL PROTECTED] * Subject: <BLANK> * Body: unsubscribe rose_forum ************************************************************************* ************************************************************************ * Rose Forum is a public venue for ideas and discussions. * For technical support, visit http://www.rational.com/support * * Post or Reply to: [EMAIL PROTECTED] * Subscription Requests: [EMAIL PROTECTED] * Archive of messages: * http://www.rational.com/support/usergroups/rose/rose_forum.jsp * Other Requests: [EMAIL PROTECTED] * * To unsubscribe from the list, please send email * To: [EMAIL PROTECTED] * Subject: <BLANK> * Body: unsubscribe rose_forum *************************************************************************
