how to queue sqlite db transactions in qt?

In my project, we have various threads that uses a singleton object - cachequery to write/read into the database. I see that that if two threads try to write on to the database, one of the thread fails to write on the db - throws sqlite - db transaction error.My aim here is to queue the transactions that fails to write on to the db. What is the best way to do so? Is there any way to queue those transactions? Or is there any other way to do so?