Tell me more ×
Database Administrators Stack Exchange is a question and answer site for database professionals who wish to improve their database skills and learn from others in the community. It's 100% free, no registration required.
up vote 1 down vote favorite

What is the difference between ERD 1 and ERD 2?

From what I understand is that ERD 2 has the many to many relationships resolved with a link entity whereas ERD 1 only shows the relationship... is there anything else?

And also at which stage do you conduct normalization.

Thanks

share|improve this question
3  
Can you add some more detail, or a link to what you're talking about? As written, this question doesn't make a whole lot of sense. – Simon Righarts Mar 4 '12 at 23:45
2  
I don't use ERD myself (because they only show one flavour of constraint i.e. foreign keys) but I would have thought that normalization must be completed before you can product an ERD. – onedaywhen Mar 5 '12 at 10:56
2  
@onedaywhen Only showing one flavour of constraint is arguably an advantage of ERDs. When you are trying to understand how your entities are interrelated you don't want a lot of "noise" from other information. Of course ERD is not suitable as (nor is it intended to be) a comprehensive source of schema documentation. It isn't good at everything, but it is great at what it's for! Nevertheless, +1 for normalization before drawing the ERD. – Joel Brown Mar 5 '12 at 15:15
I can't find any reference to ERD "1" or "2" with a quick Google - where have you come across the terms? – Jack Douglas♦ Apr 7 '12 at 11:18

Know someone who can answer? Share a link to this question via email, Google+, Twitter, or Facebook.

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.