You can use the MODIFY USER statement to change or drop CONSTRAINT object assignments for an existing user.
The following example changes assignments made in Assigning Security Constraints in a CREATE USER Statement:
MODIFY USER Joe_Smith AS CONSTRAINT = Classification_Level (TopSecret, Unclassified DEFAULT), CONSTRAINT = Classification_Country (NULL) CONSTRAINT = Classification_Job (Analyst) ;
|Classification_Level(TopSecret, Unclassified DEFAULT)||Raises the user classification level by replacing Secret with TopSecret, while retaining the DEFAULT Unclassified level.|
|Classification_Country(NULL)||Drops the Classification_Country constraint assignment from the user.|
|Classification_Job (Analyst)||Adds the new hierarchical category Classification_Job, and assigns the Analyst classification level.|
A new or changed security constraint assignment takes effect at the next user logon.