How to lock a transaction for reading a row and then inserting in Hibernate?
- by at
I have a table with a name and a name_count. So when I insert a new record, I first check what the maximum name_count is for that name. I then insert the record with that maximum + 1. Works great... except with mysql 5.1 and hibernate 3.5, by default the reads don't respect transaction boundaries. 2 of these inserts for the same name could happen at the same time and end up with the same name_count, which completely screws my application!
Unfortunately, there are some specific situations where the above is actually fairly common. So what do I do? I assume I can do a pessimistic lock where any row I read is locked for further reading until I commit or roll-back my transaction. Or I can do an optimistic lock with a version column that automatically keeps trying until there are no conflicts?
What's the best approach for my situation and how do I specify it in Hibernate 3.5 and mysql 5.1? The above table is massive and accessed frequently.
