Access to an index QSqlRelationalTableModel.

Hi,
This is my first post, because although you learn a lot from visits this forum, still have not found answer to this problem (apparently simple).
I have a QSqlRelationalTableModel and want to access the index value of the relationship without making a search related model.
For example:

Tables

Code:

---

mysql> describe user;
+--------------+-------------+------+-----+---------+-------+
| Field        | Type        | Null | Key | Default | Extra |
+--------------+-------------+------+-----+---------+-------+
| IdCategory   | int(5)      | NO   | MUL | NULL    |       |
| UserName     | varchar(40) | NO   | PRI | NULL    |       |
| IdPerson     | int(11)     | YES  |     | NULL    |       |
+--------------+-------------+------+-----+---------+-------+
 
mysql> describe category;
+--------------+-------------+------+-----+---------+----------------+
| Field        | Type        | Null | Key | Default | Extra          |
+--------------+-------------+------+-----+---------+----------------+
| IdCategory   | int(5)      | NO   | PRI | NULL    | auto_increment |
| NameCategory | varchar(80) | NO   | UNI | NULL    |                |
+--------------+-------------+------+-----+---------+----------------+

---

Code

Code:

---

QSqlDatabase Connection;
 
Connection = QSqlDatabase::addDatabase("QMYSQL");
Connection.setHostName("192.168.0.21");
Connection.setDatabaseName("brb");
Connection.setUserName("user");
Connection.setPassword("password");
 
Connection.open();
 
// table user
QSqlRelationalTableModel* modelUser;
modelUser = new QSqlRelationalTableModel;
modelUser->setTable("user");
modelUser->sort(modelUser->fieldIndex("UserName"), Qt::AscendingOrder);
modelUser->setRelation(modelUser->fieldIndex("IdCategory"), QSqlRelation("category", "IdCategory", "NameCategory"));
modelUser->select();
 
// table category
QSqlTableModel* Category;
Category = new QSqlTableModel;
Category->setTable("category");
Category->select();
 
int i, j;
for(i = 0; i < 3; 
  for(j = 0; j < modelUser->record().count(); j++)
    qDebug()<<modelUser->record(i).fieldName(j)<<" :"<<modelUser->record(i).value(j).toString();
 
qDebug()<<modelUser->record(0).value("IdCategory").toString();
qDebug()<<modelUser->record(1).value("IdCategory").toString();
qDebug()<<modelUser->record(2).value("IdCategory").toString();

---

Application output:

Code:

---

Starting C:\Qt\2010.04\projects\teste-build-desktop\debug\teste.exe...
 
"NameCategory"  : "ADMINISTRATOR" 
"UserName"  : "beatriz" 
"IdPerson"  : "0" 
 
"NameCategory"  : "MANAGER" 
"UserName"  : "ana" 
"IdPerson"  : "0" 
 
"NameCategory"  : "SUPERVISOR" 
"UserName"  : "bob" 
"IdPerson"  : "0" 
 
 
"" 
"" 
""

---

My question is whether it is possible to access the field value user.IdCategory without having to create a search algorithm in the model?
Can someone give me a direction?
The solution to this doubt, not only serves me in this simple example, but it helps me a broader understanding on the very QSqlRelationalTableModel.
My previous experience was with CBuilder / Zeoslib / MySql.
Thank you in advance and excuse my English.