Re: prevent 2 users updating same row

Use all the table's columns in the WHERE clause when updating, rather than just the primary key. Then check to see how many rows were updated. If any of the columns were changed by another user, then the WHERE clause will not get any hits, and no row will be updated. You can count the rows updated by SQL%ROWCOUNT.

John Alexander
www.SummitSoftwareDesign.com

<lfto_at_my-deja.com> wrote in message news:8rames$38r$1_at_nnrp1.deja.com...
> hi, i have the following situation where user A and B select the
> same row...then A updates and commits....then B update commits..
> problem is user B overlays user A updates....i need to prevent this.
>
> the select for update only locks other users from updating...not reading
> any ideas?
>
> here's my sql..
>
> user A: select * from miketable where user= 100;
> user B: select * from miketable where user=100;
> user A: Update miketable where user=100;
> commit;
> user B: update miketable where user=100;
> commit;
>
> thanks
> mike
>
>
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Received on Mon Oct 02 2000 - 19:22:37 CDT