Re: update from join

I wonder if this works:<br /><br />update stock s set s_superceded =  true <br />where s.s_updated < (select
max(t.s_updated)from stock t where t.s_vin = s.s_vin)<br /><br /><br /><br /><div class="gmail_quote">On Thu, May 14,
2009at 7:27 AM, Gary Stainburn <span dir="ltr"><<a
href="mailto:[email protected]">[email protected]</a>></span>wrote:<br /><blockquote
class="gmail_quote"style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">I
knowI should be able to do this but my brain's mashed today<br /><br /> I have a stock table with<br /><br />
s_stock_no             varchar primary key<br /> s_vin                   varchar<br /> s_updated              
timestamp<br/> s_superceded            boolean<br /><br /> It is possible for the same vin to exist on stock  if we
havesold and then<br /> bought back a vehicle, e.g. as a part exchange.<br /><br /> Every time a vehicle is
inserted/updatedthe s_updated field is update.<br /><br /> How can I update the table so that for each s_vin, if a
recorddoes not have<br /> the most recent s_updated value, s_superceded is set to true?<br /><br /> I can get the most
recentvalue by running:<br /><br /> select * from (select s_vin,<br />       count(s_updated) as numb,<br />      
max(s_updated)::timestampas latest<br />  from  stock<br />  group by s_vin) foo<br />  where numb > 1;<br /><br
/><br/> but I can't seem to get how I can convert this to an update statement. The num<br /> > 1 simply removed all
vehicleswith only one record.<br /><br /> I seem to think I need an update..... from..... statement<br /><br /> --<br
/>Gary Stainburn<br /><br /> This email does not contain private or confidential material as it<br /> may be snooped on
byinterested government parties for unknown<br /> and undisclosed purposes - Regulation of Investigatory Powers Act,
2000<br/><font color="#888888"><br /> --<br /> Sent via pgsql-sql mailing list (<a
href="mailto:[email protected]">[email protected]</a>)<br/> To make changes to your subscription:<br /><a
href="http://www.postgresql.org/mailpref/pgsql-sql"target="_blank">http://www.postgresql.org/mailpref/pgsql-sql</a><br
/></font></blockquote></div><br/>