Suppose your table is like :
key1 key2
1 1
1 2
2 1To get the next value to insert for key1=1 you can do this :
SELECT key2 FROM ... WHERE key1=1 ORDER BY key2 DESC LIMIT 1
Of course a UNIQUE INDEX on key1, key2 helps.
You won't be protected from two transactions adding the same value at the same time, though. The unique index will catch them and one of them will fail (constraint violation etc). Just retry the transaction until it works... or, be a warrior and lock the table... but if you do that, please do it in a function/trigger so that it's not kept locked for long !
---------------------------(end of broadcast)--------------------------- TIP 3: 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
