Обсуждение: Re: last value[Scanned]

On Wed, May 04, 2005 at 02:23:31PM +0100, Simon Hewitt wrote:
> Hi Pawel,
(...)
> Note that this returns the latest value in *your* database session. i.e. If someone has inserted a row between your
insertand retrieving the sequence number you will still receive *your*  value 
And it's exact value, that Rony needs.

p.
--
Paweł Bernat; uselessness' lover;
select'<asm'||chr(64)||'asm'||'.'||'flynet'||chr(46)||'pl>'as email;
Slowly and surely the unix crept up on the Nintendo user ...

On Wed, May 04, 2005 at 04:39:27PM -0300, Roni Warken wrote:
> Right Pawel! If I get the current value, my DB could crash in the next
> insertion.
>
> What about the trigger? Where do I get some examples to practice?but
It all depends on your needs :)
To save data integrity, you have at least three basic solutions:
a) put all queries into transaction. If someting fails in next
step, first insert will be canceled,
b) write a stored procedure (containing all necessary queries)
in a database side, and call this proc in your application,
c) create trigger on table - if your second query doesn't need
extra parameters coming from application.

Samples for a) and b) are in the documentation / examples in postgres
package. You have to choose a procedural language first (PHP is available).

--
Paweł Bernat; uselessness' lover;
select'<asm'||chr(64)||'asm'||'.'||'flynet'||chr(46)||'pl>'as email;
Slowly and surely the unix crept up on the Nintendo user ...