What is the purpose of adding constraints to a database?

The purpose of adding constraints to a database primarily revolves around enforcing rules that ensure data accuracy and integrity. Constraints are rules specified on data columns that prevent the entry of invalid data, ensuring the adherence to defined data standards.

For example, a constraint might specify that a certain field must contain a unique value, cannot be null, or must follow a particular format. This enforcement is crucial because it helps maintain the quality of the data stored within the database, ensuring that it remains reliable and usable for querying and reporting purposes. By implementing these constraints, databases prevent issues that could arise from incorrect data input, which might otherwise lead to erroneous conclusions or system malfunctions.