In Sybase Central, you add, alter, and drop column constraints on the Constraints tab of the table or Column Properties window.

To manage constraints (Sybase Central)

1. Connect to the database as a user with DBA authority.

2. In the left pane, double-click Tables.

3. Click the table you want to alter.

4. In the right pane, click the Constraints tab and modify an existing constraint or add a new constraint.