Chapter 4 Building Physical Diagrams

Defining additional check parameters for objects in a data model

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

Example

A table/entity in a data model for a clothing shop may contain check parameters defined for a column/entity attribute SIZE, which depend on the check parameters defined on another column/entity attribute CLOTHING TYPE, as clothing size for a skirt in one country may be different from the same size in another country.

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

To define additional check parameters:

1. Open the property sheet of a domain or column/entity attribute and click the Additional Checks tab.
   
2. Type a SQL expression, which may include any of the following variables:
   
   
   • %MINMAX% - Minimum and maximum values defined in Values groupbox on Standard Checks tab
   • %LISTVAL% - Customized values defined in List Values groupbox on Standard Checks tab
   • %RULES% - Validation rule expression defined on Expression tab of the Rules property sheet
3. Click OK to return to the model diagram.

Copyright (C) 2008. Sybase Inc. All rights reserved.