Database design: Conceptual ERD and Logical ERD
Conceptual ERD
This conceptual ERD provides the conceptual representation of the entities and associations for the BU-PMA website database. It provides the overall high-level view of the designed database, as describe below:
- Each user has one address
- Users can subscribe to none or as many mailing list as they prefer.
- A mailing list can be subscribed by any amount of users.
- Users have unique access credential for login to maintain their own profile.
Logical ERD
The Logical ERD details the logical representation of the entities, their associations, and the data elements for the BU-PMA website database. The designed database is in 3rd normal form.
Leong, how many mailing lists can you have? Your model seems to suggest that a user can subscribe to multiple mailing lists. I’m wondering if it’s necessary to have an entity for mailing list. We may be able to get away with having a bit attribute called “Subscribe” under the User entity.
Also, I was under the impression that the mailing list was an electronic one (for sending out mass emails), rather than one for snail mail. We may need to clarify this with the stakeholders (Prof. Kanabar).
Other than these points, it looks like you were pretty thorough. Great work!
Comment by MI — January 31, 2008 @ 5:52 pm
Thanks for your feedback Mohammad, I appreciate it. Will you be able to clarify this and get back to me prior to our second conference?
Also, is it ok for me to develop the db with Oracle SQL Plus?
-Leong.
Comment by Leong — January 31, 2008 @ 6:33 pm
Leong, I commented on this in another thread. The server doesn’t allow Oracle. Here’s what I said earlier:
The server only allows MySQL, PostGreSQL, MS Access, and MS SQL Server. SQL Server is relatively easy to manage, and if you could create all of the DDL/DML scripts using generic ANSI SQL, I can run them against the SQL Server. If there are data type anomalies, I can fix them on my end. Let’s talk about this in detail in our conference call tomorrow.
Comment by MI — January 31, 2008 @ 6:54 pm
I just updated your post to show the diagrams on the screen. I hope you don’t mind…
Comment by MI — January 31, 2008 @ 7:07 pm
Gene can you give the scope I cannot seem to find it. I need to understand where are we so far and what is missing from my behalf?
Comment by edaviles — January 31, 2008 @ 8:43 pm
Great Job Guys, I believe the newsletter should be electronic, however, if the we give the administrator the option to download a mail merge file with the physical addresses that can earn us brownie points.
Ed, I’ll post our completed scope that I submitted to Patrick.
Comment by admin — January 31, 2008 @ 10:22 pm