On 21 Mai, 15:22, [EMAIL PROTECTED] wrote: > > I did and I confirmed this by modifying the data, selecting it from > the mysql command line client to verify the changes, then running the > report again. If I exit the application and then start it again, > everything works as expected until the second instance of the report > is run.
Note that if you have a connection open in your program, especially if that connection has already been used to select data, it may be the case that you then have to perform a rollback or commit before attempting to access newly added data. The reason for this behaviour is that the DB-API modules will have begun a transaction on your behalf, and while that transaction is open, changes committed in other transactions may be unavailable to your own transaction, depending on the transaction isolation level. MySQL appears to use "repeatable read" by default [1] as its transaction isolation level, whereas PostgreSQL (for example) uses "read committed" by default [2]. I would guess that if you were using PostgreSQL, this particular problem would not have occurred, but there are other reasons to be aware of the effects of long duration transactions in PostgreSQL, and the practice of periodically performing a rollback would still be worth considering with that database system. Paul [1] http://dev.mysql.com/doc/refman/5.1/en/innodb-transaction-isolation.html [2] http://www.postgresql.org/docs/8.1/interactive/transaction-iso.html -- http://mail.python.org/mailman/listinfo/python-list
