db2 audit field - ghdrako/doc_snipets GitHub Wiki

special column that tracks changes to each row automatically

alter table <table_name> add column <field_name> TIMESTAMP NOT NULL IMPLICITLY HIDDEN FOR EACH ROW ON UPDATE AS ROW CHANGE TIMESTAMP;

Pole aktualizowane przez wewnetrzne mechanizmy db2 przy aktualizacji rekordu. HIDDEN powoduje ze w select * sie nie pokazuje

This defines a special column with the following characteristics:

• `TIMESTAMP NOT NULL'
  • The column stores a TIMESTAMP.
  • It cannot be null.
• IMPLICITLY HIDDEN
  • The column is not visible in standard SELECT * queries.
  • You can access it explicitly if needed, but it's "hidden" by default.
• FOR EACH ROW ON UPDATE AS ROW CHANGE TIMESTAMP
  • This makes the column automatically update with the current timestamp every time the row is updated.
  • It helps track the last modification time of each row—useful for auditing, replication, or change data capture (CDC).