QSqlDatabase（2）实例，QTableView显示数据库表数据

目录

前言

1、实现的功能

2、具体的代码实现

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前言

想了解QSqlDatabase基本知识的，以及增删改查的用法，可以浏览上一篇文章：

QSqlDatabase（1）基本接口，以及(增删改除)的简单实例_Ivy_belief的博客-CSDN博客

这篇主要实战，写了一个数据动态库。

1、实现的功能

先来看看要实现的页面信息：

 数据库的动态库主要实现了：数据库的增、删、改、查的功能。

（1）增加数据的功能；

（2）删除数据的功能；

（3）修改数据的功能；

（4）查找数据的功能；

（5）用QTableView显示数据库表数据；

（6）直接执行sql语句的功能；

2、具体的代码实现

数据库测试工具GUI页面的主要功能：

（1）增加数据：

bool RobotDataBaseManager::addData2DB(string strOrderId, string strEntry, string strMoney, string strPlate, string strType, string strWeight)
{if (isOrderIdExist(strOrderId))return false;QString orderId = QString::fromStdString(strOrderId);QString entry = QString::fromStdString(strEntry);QString money = QString::fromStdString(strMoney);QString plate = QString::fromStdString(strPlate);QString type = QString::fromStdString(strType);QString weight = QString::fromStdString(strWeight);QSqlQuery query;QString sql = "INSERT INTO orderData (orderId, entry, money, plate, type, weight) VALUES (:orderId, :entry, :money, :plate, :type, :weight);";query.prepare(sql);query.bindValue(":orderId", orderId);query.bindValue(":entry", entry);query.bindValue(":money", money);query.bindValue(":plate", plate);query.bindValue(":type", type);query.bindValue(":weight", weight);if (!query.exec()){qDebug()<<tr("订单Id %1 ，加入缓存失败：%2").arg(orderId).arg(query.lastError().text());return false;}qDebug()<<tr("订单Id %1 已加入缓存").arg(orderId);return true;
}

（2）删除数据的功能；

bool RobotDataBaseManager::DeleteDataById(string strOrderId)
{qDebug() << "RobotDataBaseManager::DeleteDataById: " << QString::fromStdString(strOrderId);QString orderId = QString::fromStdString(strOrderId);QSqlQuery query;QString sql = "DELETE FROM orderData WHERE orderId=:orderId;";query.prepare(sql);query.bindValue(":orderId", orderId);if (!query.exec()){qDebug() << "into DeleteDataById ERROR: " << query.lastError().text();return false;}if(m_mutex4OrderId.tryLock(1*1000)==false)return false;m_curOrderId = orderId;m_mutex4OrderId.unlock();return true;
}

（3）修改数据的功能；

bool RobotDataBaseManager::UpdateDataById(string strOrderId, string strEntry, string strMoney, string strPlate, string strType, string strWeight)
{if (!isOrderIdExist(strOrderId))return false;QString orderId = QString::fromStdString(strOrderId);QString entry = QString::fromStdString(strEntry);QString money = QString::fromStdString(strMoney);QString plate = QString::fromStdString(strPlate);QString type = QString::fromStdString(strType);QString weight = QString::fromStdString(strWeight);qDebug()<< "orderId: " << orderId;qDebug()<< "entry: " << entry;qDebug()<< "money: " << money;qDebug()<< "plate: " << plate;qDebug()<< "type: " << type;qDebug()<< "weight: " << weight;QSqlQuery query;QString sql = "UPDATE orderData SET entry = :entry, money = :money, plate = :plate, type = :type, weight = :weight WHERE orderId=:orderId;";query.prepare(sql);query.bindValue(":orderId", orderId);query.bindValue(":entry", entry);query.bindValue(":money", money);query.bindValue(":plate", plate);query.bindValue(":type", type);query.bindValue(":weight", weight);if (!query.exec()){qDebug() << "UpdateDataById ERROR: " << query.lastError().text();return false;}if(m_mutex4OrderId.tryLock(1*1000)==false)return false;m_curOrderId = orderId;m_mutex4OrderId.unlock();return true;
}

（4）查找数据的功能；

bool RobotDataBaseManager::getDataById(string strOrderId, string& strEntry, string& strMoney, string& strPlate, string& strType, string& strWeight)
{qDebug() << "[数据库]:getDataById 查询所有数据: 开始~~~~~~~~~~~~~~~~~";QString orderId = QString::fromStdString(strOrderId);QSqlQuery query;QString sql = "SELECT * FROM orderData WHERE orderId=:orderId;";query.prepare(sql);query.bindValue(":orderId", orderId);if (!query.exec()){qDebug() << "into getDataById ERROR: " << query.lastError().text();return false;}while (query.next()){QString orderId = query.value("orderId").toString();qDebug() << "取得1条订单缓存数据: " << orderId;if (!orderId.isEmpty()){strEntry = query.value("entry").toString().toStdString();strMoney = query.value("money").toString().toStdString();strPlate = query.value("plate").toString().toStdString();strType = query.value("type").toString().toStdString();strWeight = query.value("weight").toString().toStdString();}}query.exec("SELECT * FROM orderData");qDebug() << "[数据库]:SELECT * FROM orderData:";while (query.next()){// 读取字段值QString name = query.value("entry").toString();QString money = query.value("money").toString();QString plate = query.value("plate").toString();QString type = query.value("type").toString();QString weight = query.value("weight").toString();// 输出结果qDebug() << "entry:" << name << ", money:" << money << ", plate:" << plate << ", type:" << type << ", weight:" << weight;}qDebug() << "[数据库]:getDataById 查询所有数据: 结束~~~~~~~~~~~~~~~~~";return true;
}

（5）用QTableView显示数据库表数据；

void RobotDataBaseManager::on_btn_showAll_clicked()
{QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE", "Connection1");db.setDatabaseName("trawe.db"); // 数据库文件名if (!db.open()){qDebug() << "Failed to connect to database 1.";return;}QSqlQuery query(db);QString selectQuery = "SELECT * FROM orderData";if (!query.exec(selectQuery)){qDebug() << "Failed to select data from trawe.db.";return;}QSqlTableModel * model = new QSqlTableModel(this,db);model->setTable("orderData");ui->tableView->setModel(model);model->select();QStringList tables;tables << "id"<< "订单id" << "入口" << "金额" << "车牌" << "车型" << "重量" << "时间";for(int i = 1 ; i < tables.count(); i++)model->setHeaderData(i,Qt::Horizontal,tables[i]);//设置显示框表头显示model->setSort(1, Qt::AscendingOrder);//设置按照第0列排序ui->tableView->setEditTriggers(QAbstractItemView::NoEditTriggers);//设置单元格不可编辑ui->tableView->horizontalHeader()->setStretchLastSection(true);//设置最后一列填充后面表格//ui->tableView->setColumnHidden(0,true);//设置第0行隐藏ui->tableView->setColumnWidth(1,100);//设置列宽，界面看起来更舒适ui->tableView->setColumnWidth(2,100);//设置列宽，界面看起来更舒适
}

（6）直接执行sql语句的功能；

/*
(1)INSERT INTO orderData (orderId, entry, money, plate, type, weight) VALUES ("63945", "滘口", "99", "粤A777Q1", "客一", "1800");
(2)UPDATE orderData SET entry = "滘口", money = "99", plate = "粤A777Q1", type = "客一", weight = "客一" WHERE orderId="22834";
(3)DELETE FROM orderData WHERE orderId=1234567;
*/
bool RobotDataBaseManager::queryExec(string strSql)
{QString sql = QString::fromStdString(strSql);QSqlQuery query;query.prepare(sql);if (!query.exec()){qDebug() << " queryExec ERROR: " << query.lastError().text();return false;}qDebug() << "[数据库]: sql 语句执行成功: 结束~~~~~~~~~~~~~~~~~";return true;
}

上面基本也涵盖主要的代码了。

完整的项目代码已上传，需要的可以下载。

QSqlDatabase实现数据库的基本功能，以及QTableView显示数据库表数据资源-CSDN文库