Am Montag, 11. M�rz 2002 16:20 schrieb Yves Trudeau:
> Hi,
> With a MS Access 97 application we use the Sapdb "Lock" statement in
> transactions to manage concurrent access to the data. We use statements
> like:
>
> "LOCK (WAIT) ROW TbParam KEY Descrip = 'InvoiceNo' IN EXCLUSIVE MODE"
>
> In this example, the field Descrip is the primary key of the table TbParam.
> If you replace (WAIT) with (NOWAIT), the statement will not block and will
> return an error message allowing you to detect a lock issued by someone
> else. We have also chosen to work at the "uncommitted" isolation level
> mainly because of the MS Access behavior with locks. With our application,
> if Access crash (our dear old friend Dr. Watson...) the connection to the
> database is released along with the lock.
Hi,
I tried this but it didn't work for my application. Perhaps, I have not
understood erverything correct.
This is what I tried:
1. The user selects an Item in a tree view (entries are companies)
2. I determine if he want to edit or view the selected company.
3. If he wants to edit, I lock the company with the following statement:
LOCK (NOWAIT) ROW company KEY "cid" = 12 IN EXCLUSIVE MODE
4. Then I load the data of this company, so that the user can edit it.
5. When the user selects another company in the tree, I unlock the last one.
After that, I expected that a second user who opens the same company for
editing would get an error, but this didn't happen.
Where can I find the locks in the database? I guessed in table LOCK, but
there is no entry after executing the LOCK-statement.
Some additional info:
- I use the ODBC driver under Linux to connect to the database.
- The SQL statement is executed via SQLExecDirect().
- The isolation level and the commit mode is on default values (I guess
isolation level 0 and AutoCommit On, is that right?)
What am I missing? I hope anybody could help me to solve this problem.
Thanks in advance,
Ralf.
--
## Ralf Schneider
## B-connected Linux Solutions GmbH - Linux f�r den Mittelstand
## Dennis-Gabor-Str. 2, 14469 Potsdam
## www.b-connected.de
_______________________________________________
sapdb.general mailing list
[EMAIL PROTECTED]
http://listserv.sap.com/mailman/listinfo/sapdb.general
