Hello, I would like to find the best solution for this problem. I have a Java web application with Connector/J 3.0.9 and MySQL 4.0.16 with InnoDB database. When a specific action is requested, the application must perform the following sequence of operations: 1) Update or insert one or two rows in one table. 2) Read a set of rows from the same table, based on some WHERE and ORDER BY conditions. 3) Update values in one or two columns of all rows selected by the 2) action. All these points are parts of one transaction, of course. Is there a good way how to ensure that any other thread trying to perform the same transaction [with another insert/update values] will wait until the current transaction is done and commited? I've read the InnoDB manual but it contains many possibilities [lock tables, select * lock in share mode, select * for update, ...] and I am not sure which in is the best one, especially to prevent data corruption or deadlocks.

Thanks for all help. Filip