Modifying a Unique Constraint

Modify a unique constraint when you want to change the columns that the constraint is attached to, change the constraint name, or set additional properties for the constraint.

To modify a unique constraint

1. In your database diagram, select the table whose unique constraint you want to modify.
   
   
2. Right-click the table and select Properties.
   
   
3. Choose the Indexes/Keys tab.
   
   
4. Select the constraint you want to change from the Selected index list.
   
   
5. Complete an action from the following table:

   To	Follow these steps
   Change the columns that the constraint is attached to	In the Column name grid, expand the list and select the columns you want to attach the constraint to.
   Rename the constraint	Type a new name in the Index name box. Make sure that your new name doesn’t duplicate a name in the Selected index list.
   Set the clustered option (Microsoft SQL Server only)	Select the Create as CLUSTERED check box. Only one clustered index can exist per table. If a clustered index already exists, you must first clear this setting on that index.
   Define a fill factor (Microsoft SQL Server only)	Type an integer from 0 to 100 in the Fill factor box. Type 0 to accept the default fill factor.

   
   

The constraint is updated in the database when you save your table or diagram.