In previous issues, I talked about various concepts and looked at many examples of database design to help you ensure the databases you design and develop are useful and meet the needs of the people they serve. Now let's pull together some of these concepts, the four database integrities, and look at them more closely. Proper use of the four integrities—entity integrity, referential integrity, domain integrity, and business integrity—can ensure that your databases' content is accurate and consistent.