I'm having trouble executing an UPDATE-query with fmdb. It locks the application without any errors.
It stops at this line:
[db executeUpdate:@"UPDATE categories SET number_places = 21 WHERE id = 44"];
What are your other threads doing? If you're using fmdb across multiple threads, you should check out FMDatabaseQueue, and use that in place of using FMDatabase directly.
I ran into a similar situation and couldn't figure out why my application locked up.
Further investigation lead to the conclusion that I had left the FMDatabase connection open in a previous method call.
As soon as I closed the connection and executed a new query with a new connection everything worked fine.