Empty qsqlrelationaltablemodel

[Charlie42]

When I put model->select(); after relations, the model is empty, when I put it back before relations, the table displays correctly, but when I edit any cell the whole row becomes empty and gets "!" on the left. No errors.

QSqlRelationalTableModel *model = new QSqlRelationalTableModel(this, db1);
model->setTable("syllabi");
model->setEditStrategy(QSqlTableModel::OnFieldChange);
model->select();
model->setRelation(3, QSqlRelation("activity_types", "activity_type_id", "activity_type_name"));
model->setRelation(0, QSqlRelation("teachers", "teacher_id", "teacher_name"));
//model->select();
qDebug() << model->lastError();

ui->tableView->setModel(model);
ui->tableView->setItemDelegate(new QSqlRelationalDelegate(ui->tableView));
ui->tableView->horizontalHeader()->setStretchLastSection(true);
ui->tableView->setColumnHidden(9, true);