[odb-users] Loading persistent object using custom joins

[Patrick Rotsaert]

Hi,

I'm trying to find a way to load persistent objects using a join.
I know joins can be done with views, but if I understand correctly, views contain only a subset of the objects involved. I'm interested in the 'complete' objects and possible operate on them.
Consider following 2 objects:

#pragma db object
class employer
{
  ...

  #pragma db id
  unsigned long id_;

  std::string name_;
};

#pragma db object
class employee
{
  ...

  #pragma db id
  unsigned long id_;

  std::string first_;
  std::string last_;

  unsigned short age_;
  
  shared_ptr<employer> employer_;
};

Suppose I'd like to query all employers that have employees under 30 years of age.
In SQL speak, that would be something like:
	SELECT DISTINCT employer.*
	FROM employee
	NATURAL JOIN employer
	WHERE employee.age < 30
How can this be done, so I have an odb::result<employer> to work with?

Thanks,
Pat