qt 数据库 sqlite

#include <QtSql> #include <QtGui> #include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); /* qDebug() << "Available drivers:"; QStringList drivers = QSqlDatabase::drivers(); qDebug() << drivers; foreach(QString driver, drivers) qDebug() << "\t" << driver; */ if(!QSqlDatabase::drivers().contains("QSQLITE")) { //如果数据库驱动里没有SQLite,则错误警告 QMessageBox::critical(this, tr("数据库警告"), tr("系统需添加SQLite数据库驱动"), QMessageBox::Cancel); } QSqlError error = db_Init(); if(error.type() != QSqlError::NoError) { showError(error); return; } } MainWindow::~MainWindow() { delete ui; } QSqlError MainWindow::db_Init() { //QSqlDatabase::database("syscfg.dat").close(); //QSqlDatabase::removeDatabase("syscfg.dat"); QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE"); //添加数据库驱动 db.setDatabaseName(":memory:"); //数据库文件名,setDatabaseName(":memory:")指的是内存数据库 if(!db.open()) { //如果打开失败 return db.lastError(); } //创建人员组别表，2个参量 组别ID 和组别名称 QSqlQuery query; if(!query.exec("CREATE TABLE table_group(group_id INTEGER PRIMARY KEY, group_name VCHAR(10))")) { return query.lastError(); } //添加数据 query.exec("INSERT INTO table_group VALUES(1, 'teacher')"); query.exec("INSERT INTO table_group VALUES(2, 'student')"); //查看数据库 query.exec("SELECT * FROM table_group"); while(query.next()) { int group_id = query.value(0).toInt(); QString group_name = query.value(1).toString(); qDebug() << "group id=" << group_id; qDebug() << "group name=" << group_name; } return QSqlError(); } void MainWindow::showError(const QSqlError &err) { QMessageBox::critical(this, "Unable to initialize Database", "Error initializing database: " + err.text()); }