how the relation table is created?

[percywang]

I register a manytomany relation between class Parameter and class Element, but the relation table cann't be created automatically. Could anyone tell me what is the problem? Here is the code:

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in Element.h:
   typedef boost::shared_ptr<Parameter> parameter_ptr;
   typedef QList<parameter_ptr> list_parameter;
   // -- properties
   long m_id;
   QString m_symbol;
   QString m_def;
   double m_height;
   double m_width;
   list_parameter m_params;


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in Element.cpp:
namespace qx {
template <> void register_class(QxClass<Element> & t)
{
   t.id(& Element::m_id, Element::str_key1());

   t.data(& Element::m_symbol, Element::str_key2());
   t.data(& Element::m_def, Element::str_key3());
   t.data(& Element::m_height, Element::str_key4());
   t.data(& Element::m_width, Element::str_key5());
   t.relationManyToMany(& Element::m_params, "list_parameter", "parameter_element", Element::str_key1(), Parameter::str_key1());
}
}

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in Parameter.h
   typedef boost::shared_ptr<Element> element_ptr;
   typedef std::vector<element_ptr> list_element;
   // -- properties
   long m_id;
   QString m_symbol;
   QString m_def;
   QString m_unit;
   double m_value;
   list_element m_elements;


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in Parameter.cpp:
namespace qx {
template <> void register_class(QxClass<Parameter> & t)
{
   t.id(& Parameter::m_id, Parameter::str_key1());

   t.data(& Parameter::m_symbol, Parameter::str_key2());
   t.data(& Parameter::m_def, Parameter::str_key3());
   t.data(& Parameter::m_unit, Parameter::str_key4());
   t.data(& Parameter::m_value, Parameter::str_key5());
   t.relationManyToMany(& Parameter::m_elements, "list_element", "parameter_element", Parameter::str_key1(), Element::str_key1());
}
}

And in main.cpp, I create table Parameter and Element, but "parameter_element" is not created. Why?

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   QSqlError daoError = qx::dao::create_table<Parameter>();
   daoError = qx::dao::create_table<Element>();


Thanks!

[percywang]

I have fix it.

As the classes are designed without relation at first, the 2 tables were created when I ran the program. Relation table is created along with parent table's creation. So...I delete table Parameter and Element first, then run it again. Everything goes fine.

[qxorm]

I have fix it... Everything goes fine.

Great ;o)