How Do I Lock A Record, and other associated tasks

[EdAROC]

Requirements: Retrieving a Next Number. Similar to a PO# scenario, except this one's for a few customers requesting a unique ID on each pallet. This is NOT an autonumber situation.

There is a table CustLabelData with fields CustomerID and NextNum. One record for each customer requiring this service.

Currently this is a single user environment, going to multi-user. Need to avoid assigning duplicate #s.

Logic:
1. Read and lock a record, if locked then wait (display message to end user)
2. Update value (i.e. NextNum = NextNum + NumPalletLabels)
3. Unlock record

Help! I don't know how to perform steps 1 and 3.

 

[Remou]

Have a look at:
Why AutoNumber shouldn't be used in MultiUser databases (And How to ge the Unique Number)
faq700-184

Note especially dbDenyRead.