Question about method named record() in QSqlTableModel

[silentyears]

Hi all,
when i want to get the fields of one table in database, i use this code as follows:

QSqlTableModel  tableModel;
 tableModel->setTable(tableA);
 tableModel->select();
 QSqlRecord  rec = tableModel->record();
 for(int i=0, i<rec.count (), i++)
{
   QSqlField  field = rec.field(i);
   QString	fieldName = field.fieldName();
   qDebug()<<fieldName;
   // other 
   //  ....
}

QSqlTableModel  tableModel;
 tableModel->setTable(tableA);
 tableModel->select();
 QSqlRecord  rec = tableModel->record();
 for(int i=0, i<rec.count (), i++)
{
   QSqlField  field = rec.field(i);
   QString	fieldName = field.fieldName();
   qDebug()<<fieldName;
   // other 
   //  ....
}

To copy to clipboard, switch view to plain text mode 

here is my question, when i frequently open multiple talbes like this, sometimes i find that qDebug the fields sequence of table is not as the same as the table in database(e.g Oracle) , so anyone knows the reseason?
Thank you very much!