Update operations in dbms - insert operation, Database Management System

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.

Posted Date: 3/6/2013 5:34:18 AM | Location : United States







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