multiple stored procedures executed simultaneously

hi,
i have an application that uses a table to track the last invoice number used. there are around 50 users simultaneously trying to retrieve the invoice number and after doing so, increment the number for the next user.
the problem is when i issue a SELECT to get the number, increment it from the workstation, then send it back to the server via an UPDATE, there is the remote possibility of some users retrieving the same number before it being updated by the first user. (the UPDATE issued by the first user can sometimes be delayed due to slow network)
can i use stored procedures to solve this problem? i figured that if i make the SELECT and UPDATE into a single stored procedure, even if i have 50 users calling it all at the same time, each call (SELECT and UPDATE) must execute completely before the next user's call can be executed. there by making sure that the invoice number is incremented before the next user can retrieve it from the table. is this a correct assumption?
thanks in advance.
bobbob,
If you don't want to change your architecture, you could simply SELECT it
with UPDLOCK hint before you do your update.
Or, better:
BEGIN TRANS
UPDATE
Invoice
SET
NextInvoice = NextInvoice + 1
SELECT
@.iNewInvoice = NextInvoice
FROM
Invoice
COMMIT TRANS
James Hokes
"bob" <anonymous@.discussions.microsoft.com> wrote in message
news:3BD8E37A-BF4D-4D20-B18B-9121C8607697@.microsoft.com...
> hi,
> i have an application that uses a table to track the last invoice number
used. there are around 50 users simultaneously trying to retrieve the
invoice number and after doing so, increment the number for the next user.
> the problem is when i issue a SELECT to get the number, increment it from
the workstation, then send it back to the server via an UPDATE, there is the
remote possibility of some users retrieving the same number before it being
updated by the first user. (the UPDATE issued by the first user can
sometimes be delayed due to slow network)
> can i use stored procedures to solve this problem? i figured that if i
make the SELECT and UPDATE into a single stored procedure, even if i have 50
users calling it all at the same time, each call (SELECT and UPDATE) must
execute completely before the next user's call can be executed. there by
making sure that the invoice number is incremented before the next user can
retrieve it from the table. is this a correct assumption?
> thanks in advance.
> bob
>