Referentielle Integrität | Firebird

[mschaefer]

Code:

With Firebird, there is no difference

Some other SQL systems make a following distinction: NO ACTION means to allow the change if the new value in the child table is still valid after statement and all the triggers are completed (i.e. still found in the parent table of the relationship), while RESTRICT means that changing the value is not allowed at all (no change or delete is allowed if there are child records).

This is implemented in such way that NO ACTION constraint rules are checked after all other operation, and RESTRICT is checked before any other operation. In current Firebird versions, both keywords are implemented as NO ACTION.

aus: http://www.firebirdfaq.org/faq338/

Grüße // Martin