Wt

Hi there,

I'm having trouble trying to use a string as my primary key in a database.

The errors I get are essentially telling me I must use a different type; but surely that's not the case? I suspect I need to overload one or more of these functions, but I'm not sure which or how, or whether that's even the correct course of action.

The errors I'm getting are as follows:

Error 1:

/usr/local/include/Wt/Dbo/DbAction_impl.h: In member function ‘void Wt::Dbo::LoadDbAction<C>::actId(V&, const string&, int) [with V = std::basic_string<char>, C = Business, std::string = std::basic_string<char>]’:
[... I've omitted some lines here for readability, full text in the link below ...]
/usr/local/include/Wt/Dbo/DbAction_impl.h:303:3: error: no matching function for call to ‘Wt::Dbo::MetaDbo<Business>::setId(std::basic_string<char>&)’
/usr/local/include/Wt/Dbo/DbAction_impl.h:303:3: note: candidate is:
/usr/local/include/Wt/Dbo/ptr:337:8: note: void Wt::Dbo::MetaDbo<C>::setId(const IdType&) [with C = Business, Wt::Dbo::MetaDbo<C>::IdType = long long int]
/usr/local/include/Wt/Dbo/ptr:337:8: note:   no known conversion for argument 1 from ‘std::basic_string<char>’ to ‘const IdType& {aka const long long int&}’

Error 2:

db test.cpp:12:5:   instantiated from ‘void Business::persist(Action&) [with Action = Wt::Dbo::SaveDbAction<Business>]’
[... I've omitted some lines here for readability, full text in the link below ...]
/usr/local/include/Wt/Dbo/DbAction_impl.h:516:5: error: no matching function for call to ‘Wt::Dbo::MetaDbo<Business>::setId(std::basic_string<char>&)’
/usr/local/include/Wt/Dbo/DbAction_impl.h:516:5: note: candidate is:
/usr/local/include/Wt/Dbo/ptr:337:8: note: void Wt::Dbo::MetaDbo<C>::setId(const IdType&) [with C = Business, Wt::Dbo::MetaDbo<C>::IdType = long long int]
/usr/local/include/Wt/Dbo/ptr:337:8: note:   no known conversion for argument 1 from ‘std::basic_string<char>’ to ‘const IdType& {aka const long long int&}’

If required, the full compiler output is here: http://pastebin.com/5nRQXDXi

The code I'm using is essentially an extension of the code in the Wt::Dbo tutorial (http://goo.gl/QjUvV):

#include <Wt/WApplication>
#include <Wt/Dbo/Dbo>
#include <string>

class Business {
public:
  std::string name;
  template<class Action>
  void persist(Action& a)
  {
    Wt::Dbo::id(a, name, "name");
  }
};

namespace Wt {
  namespace Dbo {
    template<>
    struct dbo_traits<Business> : public dbo_default_traits {
      typedef std::string IDType;
      static IDType invalidID() {
        return std::string();
      }
      static const char *surrogateIdField() { return 0; }
    };
  }
}

class DBTestApp : public Wt::WApplication {
public:
  DBTestApp(const Wt::WEnvironment& env);
  Wt::Dbo::Session *dbSession_;
};

DBTestApp::DBTestApp(const Wt::WEnvironment& env) : Wt::WApplication(env) {
  typedef Wt::Dbo::collection< Wt::Dbo::ptr<Business> > Businesses;
  dbSession_ = session;
  Businesses businesses = dbSession_->find<Business>();
  for (Businesses::const_iterator i = businesses.begin(); i != businesses.end(); ++i) {
    business_name_->addItem((*i)->name);
  }
}

Wt::WApplication *createApplication(const Wt::WEnvironment& env) {
  return new DBTestApp(env);
}

int main(int argc, char **argv) {
  return Wt::WRun(argc, argv, &createApplication);
}

Thanks in advance for any help!

Matt