表department 字段为id,name
deptModel = new QSqlTableModel(this);
deptModel->setTable("department");
deptModel->select();
m_comboDept = new QComboBox(this);
m_comboDept->setModel( deptModel );
m_comboDept->setModelColumn( deptModel->fieldIndex("name") );
如何获得id值？
