Data Integrity Constraints in Relational Database Design

Abstract

Data integrity constraints are important in relational database design because they ensure that stored data remains accurate, valid, consistent, and reliable across database operations. These constraints define rules for how data is entered, updated, deleted, and related between tables, helping prevent invalid records, duplicate values, orphan records, and inconsistent relationships. Existing literature highlights primary key constraints, foreign key constraints, unique constraints, not-null constraints, check constraints, domain constraints, and referential integrity as major mechanisms for maintaining database correctness. However, many enterprise databases still face challenges such as weak constraint design, inconsistent relationships, missing mandatory fields, duplicate records, invalid data values, and errors caused by uncontrolled updates or deletions. This research is important because poor data integrity can affect transaction accuracy, reporting reliability, system interoperability, and business decision-making. This article discusses data integrity constraints in relational database design, focusing on entity integrity, referential integrity, domain validation, key constraints, relationship control, and enforcement rules. The study concludes that effective integrity constraints improve data accuracy, reduce database anomalies, strengthen relational consistency, and support reliable enterprise data management.