Author Topic: Data Model Column Constraints  (Read 1229 times)

greygor

  • EA Novice
  • *
  • Posts: 18
  • Karma: +0/-0
  • I love YaBB 1 Gold!
    • View Profile
Data Model Column Constraints
« on: January 10, 2002, 02:31:33 am »
I'm probably  being a bit dumb, but I'm trying to do a data model using EA and I want to put a constraint on a column such that;

If Table1.Column1 = "2" then Table1.Column2's value must exist in Table2

How do you specify this?

sparks

  • EA Administrator
  • EA User
  • *****
  • Posts: 591
  • Karma: +3/-0
    • View Profile
Re: Data Model Column Constraints
« Reply #1 on: January 13, 2002, 04:32:52 pm »
Hello,

By the sounds of what you are describing, the relationship is a foreign key, is this right?  Probably the easiest way to explain how to document a foreign key in UML is to download a copy of the DatabaseModelingInUML.pdf that we have available here:  http://www.sparxsystems.com.au/bin/DatabaseModelingInUML.pdf

It is worth having a read through the Data Modeling pdf, if you plan to use EA to document your database design etc.

Hope this helps.

Paul Mathers