What Is Constraints In Dbms?

• What is a DBMS?

A DBMS is a database management system. It is a software package that allows people to use database systems in the most effective way possible. The DBMS will allow people to develop their database by adding to it and with various data and files and then using the database to display in the data in the most convenient way to them possible.

By presenting the data in a variety of different ways it is possible to make contrasts and analyze the data in an easy to understand way and pick out facts that would not normally be seen by the human eye.

• What are the constraints of a DBMS?

A constraint in an DBMS is not how we would usually use the term 'constraint' . A constraint in a database is a rule that is programmed into the database which ensures that everything entered into the database is as accurate as possible and not subject to human error.

If phone numbers are entered into a database for example, it would be possible to use a constraint to ensure that they are entered correctly. The computer would be told that the phone number must have a certain amount of digits and will begin with a 0. This means that if someone tried to enter a phone number incorrectly, the database would alert them of the error and they would then have the opportunity to fix it.

• Common constraints

A common constraint used in databases is 'Unique'. This is a constraint put on the cells of a database which ensures that the same information is not entered into the database more than once. If customers had unique numbers then this constraint would be particularly useful because it would mean that two customers could not be assigned the same number.

Constraint is a condition to which the contents of database must conform

Constrains are basically limitation

Correctness of the data.