// file : relationship/driver.cxx // author : Boris Kolpackov <boris@codesynthesis.com> // copyright : not copyrighted - public domain #include <memory> // std::auto_ptr #include <iostream> #include <odb/database.hxx> #include <odb/session.hxx> #include <odb/transaction.hxx> #include "database.hxx" // create_database #include "employee.hxx" #include "employee-odb.hxx" using namespace std; using namespace odb::core; void print (const employee& e) { cout << e.first () << " " << e.last () << endl << " employer: " << e.employer ()->name () << endl; const projects& ps (e.projects ()); for (projects::const_iterator i (ps.begin ()); i != ps.end (); ++i) { shared_ptr<project> p (*i); cout << " project: " << p->name () << endl; } cout << endl; } int main (int argc, char* argv[]) { try { auto_ptr<database> db (create_database (argc, argv)); // Create a few persistent objects. // { // Simple Tech Ltd. // { shared_ptr<employer> er (new employer ("Simple Tech Ltd")); shared_ptr<project> sh (new project ("Simple Hardware")); shared_ptr<project> ss (new project ("Simple Software")); shared_ptr<employee> john (new employee ("John", "Doe", er)); shared_ptr<employee> jane (new employee ("Jane", "Doe", er)); john->projects ().push_back (sh); john->projects ().push_back (ss); jane->projects ().push_back (ss); transaction t (db->begin ()); db->persist (er); db->persist (sh); db->persist (ss); db->persist (john); db->persist (jane); t.commit (); } // Complex Systems Inc. // { shared_ptr<employer> er (new employer ("Complex Systems Inc")); shared_ptr<project> ch (new project ("Complex Hardware")); shared_ptr<project> cs (new project ("Complex Software")); shared_ptr<employee> john (new employee ("John", "Smith", er)); shared_ptr<employee> jane (new employee ("Jane", "Smith", er)); john->projects ().push_back (cs); jane->projects ().push_back (ch); jane->projects ().push_back (cs); transaction t (db->begin ()); db->persist (er); db->persist (ch); db->persist (cs); db->persist (john); db->persist (jane); t.commit (); } } typedef odb::query<employee> query; typedef odb::result<employee> result; // Load employees with "Doe" as the last name and print what we've got. // We use a session in this and subsequent transactions to make sure // that a single instance of any particular object (e.g., employer) is // shared among all objects (e.g., employee) that relate to it. // { session s; transaction t (db->begin ()); result r (db->query<employee> (query::last == "Doe")); for (result::iterator i (r.begin ()); i != r.end (); ++i) print (*i); t.commit (); } // John Doe has moved to Complex Systems Inc and is now working on // Complex Hardware. // { session s; transaction t (db->begin ()); shared_ptr<employer> csi (db->load<employer> ("Complex Systems Inc")); shared_ptr<project> ch (db->load<project> ("Complex Hardware")); result r (db->query<employee> (query::first == "John" && query::last == "Doe")); shared_ptr<employee> john (r.begin ().load ()); john->employer (csi); john->projects ().clear (); john->projects ().push_back (ch); db->update (john); t.commit (); } // We can also use members of the pointed-to objects in the queries. The // following transaction prints all the employees of Complex Systems Inc. // { session s; transaction t (db->begin ()); result r (db->query<employee> ( query::employer->name == "Complex Systems Inc")); for (result::iterator i (r.begin ()); i != r.end (); ++i) print (*i); t.commit (); } } catch (const odb::exception& e) { cerr << e.what () << endl; return 1; } }