Referential integrity is the automatic enforcement of referential constraints that exist between a reference table and a
referencing table. When referential integrity is enforced, the value of a foreign key exists asÂ Â a primary key value in the
reference table. In other words, when referential integrity is enforced, all of the foreign key values in, for example, theÂ
â€śdepartment codeâ€ť column in an â€śemployeeâ€ť table exist as primary key values in a â€śdepartmentâ€ť table.