How can I pass a result of a query to a function?

Question

I want to do something like this

function A(){
    session database_handler(....);

    result res = database_handler << "SELECT ....";

    functionB(res);
}

what should the parameters of functionB be?

Passing it as a pointer does not work, neither as in the example.

Thanks

Answer 1

You can safely copy cppdb::result but you may iterate over it only in one location. i.e. cppdb::result holds a reference (counted) to the result object so if you iterate over rows in functionB you can't iterate over them in functionA

So you can safely define

void functionB(cppdb::result res);

However it would be the same in terms of iterating as

void functionB(cppdb::result &res);

Also the last one faster as it does not involve reference counting overhead.