Database integrity

Database integrity ensures that data entered into the database is accurate, valid, and consistent. Any applicable integrity constraints and data validation rules must be satisfied before permitting a change to the database.

Three basic types of database integrity constraints are:

* Entity integrity, allowing no two rows to have the same identity within a table.
* Domain integrity, restricting data to predefined data types, e.g.: dates.
* Referential integrity, requiring the existence of a related row in another table, e.g. a customer for a given customer ID.