Dear all, I'm a happy Zope user (in a private environment), experienced in client-server application development but still quite green regarding to Zope. I'm trying to figure out how I can use database locking using ZSQL and MySQL. What is the case? I would like to implement a multi-user update function avoiding the obvious concurrency pitfalls. I usually implement this as follows: 1. Add a "counter" column to every table 2. With every record update, raise the counter for that record with 1 3. Before an update, first read the actual value of the counter in the database. Compare the counter in the database with the counter value of the record currently being edited. 4. If the values are not the same, another user has obviously edited the database in the meantime. The changes will not be updated to the database but the current database record will be redisplayed on the screen (with a message to the user of course). 5. If values are the same, update the database. To avoid concurrency problems, the table has to be locked before step 3 and unlocked after step 5. Because a ZSQL database connection is a permanent connection, the database will see it as 1 single session. All (anonymous) user of the web-update form will use the same session and database locking will have no effect. Now finally my question: Does anyone see a (simple) solution for this? Okay, I could create a seperate MSQL database connection for every user, but that doesn't look very Zope-ish to me. Didn't find a comparable issue in the Zope Mailing lists. Thnx in advance, Arjan.