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.