Using referential integrity for data consistency
Referential integrity ensures that data is consistent across tables.
About this task
When you define primary and foreign keys, DB2® automatically enforces referential integrity.
Introductory concepts
As a result, every value of a foreign key in a dependent table must be a value of a primary key in the appropriate parent table. However, DB2 does not enforce informational referential constraints across subsystems.
Recommendation: Use referential integrity
to ensure that a column allows only specific values. Set up a master
table of allowable values, and define its primary key. Define foreign
keys in other tables that must have matching values in their columns.
In most cases, you should use the SET NULL delete rule.