---

Constraint

---

In the Oracle implements the concepts of Constraint

What is Constraint?

A Constraint is a statement that describes some features of our data which is store in the Database.

When a Constraint is validate and enabled then database does not allow entering the data which is making statement to be false.
All the Constraint is stored in the data dictionary.

The Constraint also prevents the deletion of a table if there are any dependencies from the other table. Constraints enforce rules on the data whenever a row is inserted, updated, or deleted from a table. There are various type of Constraints.

1: NOT NULL Constraints

2: UNIQUE KEY Constraints

3: PRIMARY KEY Constraints

4: FOREIGN KEY Constraints

5: CHECK Constraints

---