如何从sqlite数据库中删除特定行并与qlineedit绑定？

Question

我可以使用手动SQL查询命令删除特定行。但无法从QLineEdit删除。如何与QLineEdit绑定？

这是我的代码：

person_name = ui->txt_UserName->text ();
mobile_number = ui->txt_Pass->text ();

//delete values
QString deleteStatement = "DELETE FROM phonebook_info WHERE  user_name = ':person_name'";
query->bindValue (":person_name", person_name);

query->exec (deleteStatement);

if(query->exec ()){
    QMessageBox::information (this, "Information!", "Row Deleted.", QMessageBox::Ok);
    ui->statusBar->showMessage ("Row Deleted.");
} else {
    QMessageBox::critical (this, "Information!", "Row not Deleted.", QMessageBox::Ok);
    ui->statusBar->showMessage ("Row not Deleted.");
}

查询已执行但未删除。我做错了什么？

Answer 1

语法看起来不对，您拨打query->exec()两次。这是您应该如何运行预准备语句：

QSqlQuery query = new QSqlQuery(databaseInstance);
bool ok = query->prepare(deleteStatement);
if (!ok) {
    qWarning() << "SQL error:" << deleteStatement;
}
query->bindValue(":person_name", person_name);
query->exec();