QSqlDatabase、QSqlQuery、QSqlRecord、Sqlite用法

使用QSqlDatabase、QSqlQuery、QSqlRecord、Sqlite数据库实现一个简单的界面查询

1. 创建Sqlite数据库，表

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "QSqlDatabase"
#include "QSqlQuery"
#include "QSqlError"
#include "QMessageBox"
#include "QFileDialog"
#include "QSqlRecord"MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);// ui->openBtn->setEnabled(true);// ui->qryBtn->setEnabled(false);
}MainWindow::~MainWindow()
{delete ui;
}//打开数据库连接
void MainWindow::on_openBtn_clicked()
{QString aFile= QFileDialog::getOpenFileName(this,"选择文件","","SQLite 数据库(*.db3)");if (aFile.isEmpty())return;DB = QSqlDatabase::addDatabase("QSQLITE"); //添加 SQLITE 数据库驱动DB.setDatabaseName(aFile);// QTextCodecif (!DB.open()) {QMessageBox::critical(NULL, "错误", "数据库连接失败", QMessageBox::Ok, QMessageBox::Ok);qDebug() << "FAIL" << DB.lastError().text();} else {QMessageBox::information(NULL, "信息", "数据库连接成功");qDebug() << "SUCCESS";// ui->openBtn->setEnabled(false);// ui->qryBtn->setEnabled(true);}
}void MainWindow::on_qryBtn_clicked()
{qryModel= new QSqlQueryModel(this);selModel= new QItemSelectionModel(qryModel,this);// ui->tableView->model()ui->tableView->setModel(qryModel);ui->tableView->setSelectionModel(selModel);qryModel->setQuery("SELECT id,name, Gender, gender, hobby "" FROM t_user ORDER BY id");if (qryModel->lastError().isValid()){QMessageBox::information(this, "错误", "数据表查询错误,错误信息\n"+qryModel->lastError().text());return;}QSqlRecord rec= qryModel->record(); //获取空记录，用于获取字段序号//设置字段显示标题qryModel->setHeaderData(rec.indexOf("id"),Qt::Horizontal, "序号");qryModel->setHeaderData(rec.indexOf("name"), Qt::Horizontal, "姓名");qryModel->setHeaderData(rec.indexOf("gender"), Qt::Horizontal, "性别");qryModel->setHeaderData(rec.indexOf("hobby"), Qt::Horizontal, "爱好");
}

mainwindow.h文件

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QSqlDatabase>
#include <QSqlQueryModel>
#include <QItemSelectionModel>QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACEclass MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();
private:QSqlDatabase DB; //数据库连接QSqlQueryModel *qryModel; //Query数据模型QItemSelectionModel *selModel; //选择模型private slots:void on_openBtn_clicked();void on_qryBtn_clicked();private:Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H