Re: Correct Entity Relationship Diagram Notation.

Hi,

> What is the correct Entity Relationship Diagram Notation or the most widely
> used notation?

Right, not "the correct" but most used (thus there is no the most correct statistics about such a usage :) The major criteria to choose either notation is its convinience/ease of readability to database analysts/developers. (Anyways all market leading data modeling tools (such as ERwin) support at least two notations, e.g IE and IDEF. So you can switch between notations without any harm to your data model.)

Nowadays 2 mostly used in IT world ER diagrams' notations are: IE (Information Engineering) and IDEF1X (USAF ICAM Definition method). (There also some old notations like Chen' notation. To my knowledge, IE notation is modified Chen's notation.)
IE notation grows from IE set of structured analysis techniques and most widely used in Europe, also in the United States. IDEF1X is comes together with IDEF0 (which is US FIPS (federal) standard) method which is mostly used by US military and govermental organizations.

(Thus I can easily read and understand both IE/CODASYL and IDEF notations,IMHO IE notation is more informative and provides more readabilty for people who's tired of reading ER diagrams. You may notice that IE relationship symbols are more clearly identify the particular type of relashionship, such as its cardinality, mandatory or not, identifying or not.)

Alex P
mcdba,ocp

~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~ "Daniel Watkins" <daniel.watkins_at_baesystems.com> wrote in message news:3d21a712$1_at_pull.gecm.com

> What is the correct Entity Relationship Diagram Notation or the most widely
> used notation?
>
> What does the entity relationship diagram consist of?
>
> I have seen so many different notiations that I have becmoe a little
> confused.
>
> Thank you,
>
> Daniel Watkins.

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