Home > Archive > PHP with PostgreSQL > May 2005 > Re: last value[Scanned]









You are viewing an archived Text-only version of the thread. To view this thread in it's original format and/or if you want to reply to this thread please [click here]

 

Author Re: last value[Scanned]
Pawel Bernat

2005-05-04, 9:24 am

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 insert and 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 ...

---------------------------(end of broadcast)---------------------------
TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql
.org

Pawel Bernat

2005-05-05, 3:24 am

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 ...

---------------------------(end of broadcast)---------------------------
TIP 7: don't forget to increase your free space map settings

Sponsored Links





Also available: Server administration forum archive | Web Design forum archive | Software forum archive | Hardware reviews archive | Programming forum archive

Copyright 2008 droptable.com