Re: equivalent of lock and update in SQL

[Steve Richter <stephenrichter@xxxxxxxxx>]

ok. good.  For some reason I was thinking the FETCH would not lock the
record. Which does not make sense.

so I just have to declare the cursor to select a single record from the
file. The FETCH locks it. The UPDATE releases the lock.




On Wed, Mar 20, 2013 at 3:22 PM, DeLong, Eric <EDeLong@xxxxxxxxxxxxxxx>wrote:

> I think all you need to do is add the "for update of ... " clause.  As I
> recall, this forces the fetch to lock the current row, pending the "UPDATE
> ... WHERE CURRENT OF myCursor".
>
> -Eric DeLong
>
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx [mailto:
> midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Steve Richter
> Sent: Wednesday, March 20, 2013 1:30 PM
> To: Midrange Systems Technical Discussion
> Subject: equivalent of lock and update in SQL
>
> in rpg record I/O I lock a control record, increment a control number, then
> update the control record.  Which reliably gives me a unique value.
>
> C** GET NEXT SID NUMBER FROM WCMAST
> C     inwacd        CHAIN     WCREC
> C                   EVAL      WCNSID += 1
> C                   UPDATE    WCREC
>  /free
>       outSid      = wcnsid ;
>  /end-free
>
> Can I use SQL to do the same thing?
>
> thanks,
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