Setting sqlite config SQLITE_CONFIG_SERIALIZED returns SQLITE_MISUSE on iOS 5

Question

With the release of iOS 5 we are getting more and more errors when setting the serialized option for the sqlite database (so its save to be used for multithreading). We are

Answer 1

Is the sqlite3_config() called before sqlite3_initialize()? The function returns SQLITE_MISUSE if called after sqlite3_initialize() and before sqlite3_shutdown(). See http://www.sqlite.org/c3ref/config.html for more details.

Answer 2

I struggled long and hard with this as well and finally got the solution.

As @enobufs said, sqlite3_config() needs to be called before sqlite3_initialize(). However, the OS might initialize SQLite for us so I also do a sqlite3_shutdown() before the sqlite3_config().

1. sqlite3_shutdown()
2. sqlite3_config()
3. sqlite3_initialize().

Then its also necessary to use the same connection for every query as it is the access to the database connection that gets serialized. As described here http://www.sqlite.org/capi3ref.html#sqliteconfigserialized

So I create a connection as soon as the app starts up and the pass that connection to every class that needs it.