BCA / B.Tech 4 min read

What is a Domain in DBMS?

What is a Domain in DBMS?

In a Database Management System (DBMS), a Domain is the set of all permissible values for a particular attribute (column). It acts as a constraint, ensuring that the data entered into a column is valid and consistent.

A domain defines the data type for a column and can also specify a range or a specific set of allowed values.

Example:

If you have an `Age` column in a `STUDENTS` table, you might want to restrict the age to be between 18 and 25. The domain for the `Age` column would be integers from 18 to 25. This can be enforced using a `CHECK` constraint:

Age INTEGER CHECK (Age BETWEEN 18 AND 25)

By defining a domain, you maintain data integrity and ensure that only appropriate data is stored in the database.