Update violations for UPDATE

An update may violate the domain and NOT NULL constraint on an attribute being modified.

And any other constraint may also be violated depending on the attribute being updated:

• Updating primary key $PK$: similar to a DELETE, followed by INSERT See Update violations for INSERT and Update violations for DELETE.
• Updating a foreign key $FK$: may violate Referential Integrity
• Updating an ordinary attribute: can only violate Domain Constraint (Databases)