On Thu, 2007-06-07 at 09:44 +0100, Richard Huxton wrote: > Sebastjan Trepca wrote: > > Hi, > > > > as I understood, when you create a table which inherits some other > > table, the constraints and indexes do not go to the child table hence > > you have to create a separate ones in there. That means you cannot > > depend that you won't have duplicate IDs in both tables. Right? > > > > BUT...what if child table and parent table both use the same sequence > > for the primary key. Would the duplication still be an issue? > > Well, if you *always* use the sequence you'll be OK (until you run out > of numbers), but it won't stop you manually supplying your own values.
If you must keep the primary key unique across a set of tables, you need to create another table to index the keys and record which table each key is in. Use triggers to keep the index table up to date. -- Oliver Elphick [EMAIL PROTECTED] Isle of Wight http://www.lfix.co.uk/oliver GPG: 1024D/A54310EA 92C8 39E7 280E 3631 3F0E 1EC0 5664 7A2F A543 10EA ======================================== Do you want to know God? http://www.lfix.co.uk/knowing_god.html ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
