ASA SQL User's Guide
  Ensuring Data Integrity
    Using table and column constraints

Working with table and column constraints in Sybase Central

In Sybase Central, you add, alter, and delete column constraints on the Constraints tab of the table or column property sheet.

To manage constraints

1. Open the Tables folder.

2. In the right pane, double-click the table you want to alter.

3. The right pane has separate tabs for unique constraints and check constraints.

4. Make the appropriate changes to the constraint you wish to modify. For example, to add a table or column constraint, click the Check Constraints tab and choose File > New > Table Check Constraint or File > New > Column Check Constraint.