reverse engineering wipes relationships

[cgoatly]

Hi,
I have a bizarrely created database where the backend has no foreign key relationships, it only states the primary keys and then the foreign keys are held together in the front end. I have used ea to reverse engineer the backend and then am drawing in the associations on the data model diagram.
Now the database has loads of tables so I wanted to import a few tables at a time, draw the associations for those and then import a few more and do the same. The problem I'm having is that when i try importing tables for the second time all the associations that I had previously drawn disappear and I have to start over.
Does anyone have any advice on what to do, or any ideas on how to overcome this? This is my first time of using it so I could well just be doing something wrong!
Thanks a lot
Caroline

[Bruno.Cossi]

Hi Caroline,

I am not sure whether there is a way to preserve the relationships you have created when importing the schema again (I seem to remember that there was a discussion about this elsewhere on the forum recently).
However, I think there is a simple solution to this.
1. Import all the tables
2. Create a new diagram
3. Place (drag and drop) only the tables you want to define the relationships for onto the diagram
4. Draw the relationships
5. Keep adding the tables onto the diagram and adding the relationships

Does this help?

Bruno

[cgoatly]

Hi again,

thanks for that, yes it does help. Although pity I didn't think of it before, as now I've done about 30 of the tables and realised I need another couple which I didn't import (you see I'm not modelling the whole database so I don't need all of the tables).
So yes I will have to do what you sugeested and start again. It's just very frustrating...why did they design it like that..?!!

Caroline

[Bruno.Cossi]

Hi,

well, I guess that since EA is not principally a database modeling tool, the focus has been elsewhere. The ability of modeling database structures in EA is a nice addition, but it is really nothing but a specific application of Class Diagrams.
Having said that, EA will likely not (at least not any time soon) offer all of the abilities of the tools that do nothing but database modeling. Conceptual/Logical and Physical diagrams, support for DBMS-specific objects (e.g. packages in Oracle) etc.
Either way, happy to have helped, at least a little bit :-)

Bruno

[cgoatly]

I see what you're saying yes. Thanks a lot for your advice  

Caroline