The common and error prone way of saving things in the database is to open a transaction, enter a try clause, do something then commit. If we catch an exception, then we rollback. something like this: begin transaction; try { do something; do something else; commit; } catch (Any exception which may occur) { rollback; } There are 3 things which can go wrong. 1 we forget to begin the transaction, 2 we forget to commit and 3 we do not rollback properly. What ...