Slide
5- 41
Copyright © 2007 Ramez Elmasri and
Shamkant B. Navathe
Possible violations for
each operation
nUPDATE
may violate domain constraint and NOT NULL constraint on an attribute being
modified
nAny
of the other constraints may also be violated, depending on the attribute being
updated:
nUpdating the primary key (PK):
nSimilar to a DELETE followed by an INSERT
nNeed to specify similar options to DELETE
nUpdating a foreign key (FK):
nMay violate referential integrity
nUpdating an ordinary attribute (neither PK nor FK):
nCan only violate domain constraints