Types of Data Integrity
Let's look at the different types of data integrity:
- Entity integrity: This defines each row as unique within the table. No two rows can have the same name. To achieve this, a primary key can be defined. This field contains a unique identifier—no two rows can contain the same unique identifier.
- Referential integrity: Referential integrity is about relationships. When two or more tables have a relationship, we must ensure that the value of the foreign key always matches the value of the primary key, otherwise the record is orphaned.
Referential integrity prevents adding records to a related table if there is no associated record in the primary or parent table, changing values in a primary table that can result in orphaned records in a related table, and deleting records from a primary table if there are matching related records.
- Domain integrity: This is primarily concerned with the validity of entries for a given column. It is important...