er diagram

Danielle et jean Thierry-Mieg mieg at kaa.crbm.cnrs-mop.fr
Fri Oct 18 03:13:27 EST 1996


As I understand it, the file models.wrm in acedb is
the functional equivalent, for an object oriented database, 
of the ER diagram of a relational db

There is a difference, because objects are defined
intrinsically, by their unique key, rather than
virtually by content as in a relational db

In addition, in the particular case of acedb, the unique
key is expoartable as the string doublet
  (className:objectName)

I beleive therefore that a classic ER diagram does not
correctly describe the content of an OO database. Although
it may be valuable for people used to this approach, it
should always be considered as an approximation.

Pleasae correct me if I am mistaken.

Jean




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