Definition of Constraint
A constraint is defined in integrity constraint to specify rules for the data in a database. If there is any violation between the constraint and the data action, the action is aborted by the constraint. It can be specified when the table is created using the CREATE TABLE statement or after the table is created using the ALTER TABLE statement. It can be specify in two ways:
- Column level constraint
- Table level constraint
Column level constraint
It refers to a single column in the table and do not specify the column name. It is also known as inline specification.
Table level constraint
It refers to one or more column in the table and specifies the names of the column to which they apply. It is also known as outline specification.
Types of Constraints
Oracle Database creates six types of constraints (more…)
This content is restricted to site members. If you are an existing user, please log in. New users may register below.