c++ - QSqlRelation 不工作

Question

这是我的代码:

QSqlRelationalTableModel *model = new QSqlRelationalTableModel(this, db1);
model->setTable("syllabi");
model->select();
model->setRelation(0, QSqlRelation("teacher_id", "teachers", "teacher_name"));
ui->tableView->setModel(model);
qDebug() << model->lastError();

我试图用“教师”表中的 teacher_name 替换 teacher_id 列，但它仍然显示 teacher_id 列。调试显示:

QSqlError("", "", "")

专栏信息: http://i.stack.imgur.com/WP83F.png

Answer 1

尝试

model->setRelation(0, QSqlRelation("teachers", "teacher_id", "teacher_name"));
model->select();

在 setRealation() 之后选择()