Chapter 4 Building Conceptual Data Models

Defining additional check parameters for objects in a CDM

You can write an SQL statement using the following standard variables defined as standard check parameters and validation rules:

Variable Description
%MINMAX%, Minimum and maximum values defined in Values groupbox on Standard Checks page
%LISTVAL% Customized values defined in List Values groupbox on Standard Checks page
%RULES% Validation rule expression defined on Expression page of the Rules property sheet

You define additional check parameters for data constraints where standard check parameters are not sufficient.

Example

An entity in a data model for a clothing shop may contain check parameters defined for an entity attribute SIZE, which depend on the check parameters defined for another entity attribute COUNTRY, as clothing size for a skirt in France may be different from the same size in the United States.

In this case an expression is required to create a constraint which uses check parameters defined for both entity attributes.

Steps To define additional check parameters for objects:

  1. Click the Additional Checks tab in the property sheet of a domain or an entity attribute to display the corresponding page.
  2. Type SQL expression using the variables %MINMAX%, %LISTVAL%, and %RULES%.
  3. Click OK.

 

Copyright (C) 2005. Sybase Inc. All rights reserved.