Re: Confused about DDL and DDS

rob@xxxxxxxxx wrote:

Not one of the samples posted here included any constraints:
referential, check or otherwise. All stuff that was impossible
with DDS. And can only be tacked on after the fact with
ADDPFCST.

The accusation that the constraint information can "only be tacked on after the fact" is disingenuous. That the DDL can include constraint definitions in the CREATE statement is nice; great even. However in SQL DDL, constraints are often seen to be added "after the fact" using the ALTER TABLE even if only for documentation purposes. For referential constraints it may even be an effective requirement to do a separate ALTER due to a parent not-yet-created scenario. Irrespective of when or by what interface, by SQL or the CL command ADDPFCST, the constraint is still a constraint *and* the constraints are enforced all the same, irrespective of whether the data is being manipulated by DML or RLA.

Also FWiW, Lloyd [as the second to reply to the thread] did actually post the DDL for a CREATE TABLE with a PRIMARY KEY, and later the script has an ALTER TABLE that added a CHECK CONSTRAINT. Alan posted one with a slew of ALTERs done post-create to add CHECKs to several of the columns.

Regards, Chuck