CppDB/docs/transaction.txt

/*! \page transaction Handling Transactions

\ref cppdb::session class has \ref cppdb::session::begin() "begin()", \ref cppdb::session::commit() "commit()", \ref cppdb::session::rollback() "rollback()" member functions that allow you to handle transactions. However you are not expected to use them directly for RAII reasons.

There is a transaction scope guard \ref cppdb::transaction that allows to wrap transactions in exception safe way.
In the \ref cppdb::transaction::transaction(cppdb::session&) "transaction guard's constructor" you specify the SQL \ref cppdb::session "session" you want to 
run transaction on and when operations is completed you call its \ref cppdb::transaction::commit() "commit()" function to complete
the transaction or \ref cppdb::transaction::rollback() "rollback()"

If the transaction wasn't either committed or rolled back, it would be automatically rolled back during stack unwind.

For example:

\code
cppdb::transaction guard(sql);
sql << "UPDATE accounts SET amount=amount+? WHERE user=?" << amount << receiver << cppdb::exec;
sql << "UPDATE accounts SET amount=amount-? WHERE user=?" << amount << sender << cppdb::exec;
guard.commit();
\endcode

This would execute a transaction in exception safe way.


*/