Browse Prior Art Database

Conceptual Graphs to Represent Information Model Constraints

IP.com Disclosure Number: IPCOM000104151D
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Potok, TE: AUTHOR

Abstract

A method for representing entity relationship model constraints as conceptual graphs is disclosed. Conceptual graphs provide a means of representing constraints in a far more readable format than is currently available.

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Conceptual Graphs to Represent Information Model Constraints

      A method for representing entity relationship model constraints
as conceptual graphs is disclosed.  Conceptual graphs provide a means
of representing constraints in a far more readable format than is
currently available.

      Fig. 1 shows an entity relationship (ER) model of a programmer,
department, laboratory, company, and their relationships.
Fig. 1.  An ER diagram of how a programmer relates to a company

There is a constraint on this ER diagram:  A programmer cannot be a
member of two departments within the same company.

      This constraint cannot be represented in an ER diagram, but
must be stated textually as shown below.
if PROGRAMMER X
   -is member of -
      DEPARTMENT Y

AND
COMPANY W
   -MANAGES-
      DEPARTMENT Y
then NOT
   (PROGRAMMER X
      -is a member of-
         DEPARTMENT Z

AND
COMPANY W
   -manages-
      DEPARTMENT Z)

Fig. 2.  A textual representation of this constraint

      This constraint can be represented graphically, using
Conceptual Graphs.
Fig. 3.  The Conceptual Graph representation of this constraint

      To use Conceptual Graphs to represent constraints, the
following steps must be performed:

1.  Convert the constraint to first-order logic.
2.    Represent the first-order logic constraint as a conceptual
    graphs

A conceptual graphs is a precise means of graphical display
first-order logic.