Update Operations and Dealing with Constraint Violations

There are three basic operations to be executes on relations:

• Insertion
• Deletion
• Update

The INSERT Operation:

The insert operation permits us to insert a new tuple in a relation. When we try to insert a new record, then any of the following four types of constraints can be violated:

• Key constraint: If the value of the key attribute in new tuple t is the similar as in the existing tuple in relation R.
• Domain constraint: If the value given to an attribute lies outside the domain of that attribute.
• Referential Integrity constraint: If the value of the foreign key in t refers to a tuple that doesn't show in the referenced relation.

 • Entity Integrity constraint: If the primary key attribute value of new tuple t is given as null.