Oracle C++ Call Interface Programmer's Guide

Overview of Navigational Access
and enables you to access and modify the object’s attributes and follow references
from that object to other objects. Your application also controls when modified
objects are written back to the database server.
OCCI requires only that you dereference the REF in the same way you would
dereference any C++ pointer. Dereferencing the REF transparently materializes the
object as a C++ class instance.
Continuing the Address class example from the previous section, assume that the
user has added the following method:
string Address::getState()
{
return state;
}
To dereference this REF and access the object's attributes and methods:
string state = addr_ref->getState(); // -> pins the object
The first time Ref (addr_ref) is dereferenced, the object is pinned, which is
to say that it is loaded into the object cache from the database server. From then on,
the behavior of operator -> on Ref is just like that of any C++ pointer (T
*). The object remains in the object cache until the REF (addr_ref) goes out of
scope. It then becomes eligible for garbage collection.
Now that the object has been pinned, your application can modify that object.
Manipulating Object Attributes
Manipulating object attributes is no different from that of accessing them as shown
in the previous section. Let us assume the Address class has the following user
defined method that sets the state attribute to the input value:
void Address::setState(string new_state)
{
state = new_state;
3-16 Oracle C++ Call Interface Programmer’s Guide
Note: This section deals with a simple pin operation involving a
single object at a time. For information about retrieving multiple
objects through complex object retrieval, see the section Overview
of Complex Object Retrieval on page 3-19.