Re: arbitrary number of values from a sequence

On Sat, May 05, 2001 at 02:33:22PM +0200, Gyozo Papp wrote:
> Ok. I'm looking for another solution.
>
> The reason why I'm not dealing with sequence's increment is that
> there is no way to set an appropiate limit, sometimes I need 5, sometimes 17.

CREATE TABLE myseq (
val integer NOT NULL;
);

psuedocode:

func (integer howmany)
...
BEGIN TRANSACTION;
oldval := SELECT val FROM myseq FOR UPDATE;
newval := oldval + howmany;
UPDATE myseq SET val = newval;
COMMIT;

for i := oldval; i < newval; incr i
do stuff

...

You might want to use LOCK instead of FOR UPDATE since its behavior
depends on the TRANSACTION ISOLATION LEVEL.

--
Eric G. Miller <egm2(at)jps(dot)net>