QT数据库编程

ui界面

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include 
#include 
#include 
MainWindow::MainWindow(QWidget* parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    //    this->setCentralWidget(ui->splitter);
    ui->tableView->setSelectionMode(QAbstractItemView::SingleSelection); //设置择的模式只可以选中一个
    ui->tableView->setAlternatingRowColors(true); //设置不同行颜色
    //设置分组
    QButtonGroup* group = new QButtonGroup(this);
    group->addButton(ui->radioButton);
    group->addButton(ui->radioButton_2);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_pushButton_clicked()
{
    QString file = QFileDialog::getOpenFileName(this, "选择文件", "../", "SQLITE(*.*)");
    if (file.isEmpty())
        return;
    db = QSqlDatabase::addDatabase("QSQLITE"); //添加驱动
    db.setDatabaseName(file); //加入文件
    if (!db.open())
        QMessageBox::warning(this, "错误", "打开失败");
    else {
        openTable(); //打开数据库表格
    }
    qDebug() << "完成";
}

void MainWindow::do_current_changed(const QModelIndex& current, const QModelIndex&)
{
    Q_UNUSED(current);
    qDebug() << "当前改变";
    ui->pushButton_8->setEnabled(tabModel->isDirty()); //是改过的
}

void MainWindow::do_current_row_changed(const QModelIndex& current, const QModelIndex&)
{
    qDebug() << "点击了单元格";
    if (!current.isValid()) {
        ui->label_10->clear();
        return;
    }
    ui->pushButton_8->setEnabled(true);
    //映射
    dataMapper->setCurrentIndex(current.row());

    QSqlRecord curRecord = tabModel->record(current.row());
    if (!curRecord.isEmpty()) {
        qDebug() << "数据" << curRecord;
    }
}

void MainWindow::openTable()
{
    //创建模型，打开数据库表格
    tabModel = new QSqlTableModel(this, db);
    tabModel->setTable("test"); //设置数据库表名称
    tabModel->setEditStrategy(QSqlTableModel::OnManualSubmit); //手动提交
    tabModel->setSort(tabModel->fieldIndex("id"), Qt::DescendingOrder); //按id 降序排序， 升序 AscendingOrder
    if (!tabModel->select()) {
        QMessageBox::critical(this, "错误", tabModel->lastError().text());
    }
    ui->statusbar->showMessage(QString("记录条数为 %1").arg(tabModel->rowCount()));
    //设置字段显示的标题
    tabModel->setHeaderData(tabModel->fieldIndex("id"), Qt::Horizontal, "ID号");
    tabModel->setHeaderData(tabModel->fieldIndex("name"), Qt::Horizontal, "姓名");
    // model /view
    selModel = new QItemSelectionModel(tabModel, this);

    ui->tableView->setModel(tabModel);
    ui->tableView->setSelectionModel(selModel); //注意：必须先设置模型在设置选择模型，否则不生效

    //    ui->tableView->setColumnHidden(tabModel->fieldIndex("id"), true); //隐藏数据

    //代理
    QStringList str;
    str << "男"
        << "女";
    delegateSex.setItems(str, false);
    ui->tableView->setItemDelegateForColumn(tabModel->fieldIndex("name"), &delegateSex);
    //字段与widget映射
    dataMapper = new QDataWidgetMapper(this);
    dataMapper->setModel(tabModel);
    dataMapper->setSubmitPolicy(QDataWidgetMapper::AutoSubmit); //数据自动提交
    dataMapper->addMapping(ui->spinBox, tabModel->fieldIndex("id"));
    dataMapper->addMapping(ui->lineEdit, tabModel->fieldIndex("name"));
    dataMapper->toFirst(); //显示第一条记录
    // 状态发生变化
    //    ui->pushButton->setEnabled(false);
    //获取字段名更新
    QSqlRecord emptyRec = tabModel->record();
    qDebug() << "emptyRec = " << emptyRec;
    for (int i = 0; i < emptyRec.count(); ++i) {
        ui->comboBox->addItem(emptyRec.fieldName(i));
    }
    //信号连接
    connect(selModel, &QItemSelectionModel::currentChanged, this, &MainWindow::do_current_changed);
    connect(selModel, &QItemSelectionModel::currentRowChanged, this, &MainWindow::do_current_row_changed);
}

void MainWindow::on_pushButton_3_clicked()
{
    QModelIndex index = ui->tableView->currentIndex();
    QSqlRecord rec = tabModel->record();
    rec.setValue(tabModel->fieldIndex("name"), "王五");
    tabModel->insertRecord(index.row(), rec);

    selModel->clearSelection();
    selModel->setCurrentIndex(tabModel->index(tabModel->rowCount() - 1, 1), QItemSelectionModel::Select);
    //更新状态栏
    ui->statusbar->showMessage(QString("记录条数为 %1").arg(tabModel->rowCount()));
}

void MainWindow::on_pushButton_2_clicked()
{
    QSqlRecord rec = tabModel->record();
    rec.setValue(tabModel->fieldIndex("name"), "王五");

    tabModel->insertRecord(tabModel->rowCount(), rec);

    selModel->clearSelection();
    selModel->setCurrentIndex(tabModel->index(tabModel->rowCount() - 1, 1), QItemSelectionModel::Select);
    //更新状态栏
    ui->statusbar->showMessage(QString("记录条数为 %1").arg(tabModel->rowCount()));
}

void MainWindow::on_pushButton_4_clicked()
{
    QModelIndex index = ui->tableView->currentIndex();
    tabModel->removeRow(index.row());
    ui->statusbar->showMessage(QString("记录条数为 %1").arg(tabModel->rowCount()));
}

void MainWindow::on_pushButton_5_clicked()
{
    QString aFile = QFileDialog::getOpenFileName(this, "选择图片", "", "(*.jpg)");
    if (aFile.isEmpty())
        return;
    QFile* file = new QFile(aFile, this);
    if (file->open(QIODevice::ReadOnly)) {
        QByteArray arr = file->readAll();
        file->close();
        QSqlRecord rec = tabModel->record(selModel->currentIndex().row());
        rec.setValue("photh", arr); //设置数据
        tabModel->setRecord(selModel->currentIndex().row(), rec); //设置行数据
        QPixmap pix;
        pix.load(aFile); //加载图片
        ui->label_10->setPixmap(pix.scaledToWidth(pix.width()));
    }
}

void MainWindow::on_pushButton_6_clicked()
{
    QSqlRecord rec = tabModel->record(selModel->currentIndex().row());
    rec.setNull("photh");
    tabModel->setRecord(selModel->currentIndex().row(), rec);
    ui->label_10->clear();
}

void MainWindow::on_pushButton_7_clicked()
{
    if (tabModel->rowCount() == 0)
        return;
    for (int i = 0; i < tabModel->rowCount(); ++i) {
        QSqlRecord rec = tabModel->record(i);
        rec.setValue("name", rec.value("name").toInt() + 100);
        tabModel->setRecord(i, rec);
    }
    if (tabModel->submitAll()) { // submit不成功，需要all
        QMessageBox::information(this, "成功", "涨工资成功");
    }
}

void MainWindow::on_pushButton_8_clicked()
{
    bool ret = tabModel->submitAll();
    if (!ret) {
        QMessageBox::critical(this, "失败", "保存失败");
    }
}

void MainWindow::on_pushButton_9_clicked()
{
    tabModel->revertAll(); //还原
}

void MainWindow::on_comboBox_currentIndexChanged(int index)
{
    if (ui->radioButton->isChecked()) {
        tabModel->sort(index, Qt::AscendingOrder);
    } else {
        tabModel->sort(index, Qt::DescendingOrder);
    }
    tabModel->select();
}

void MainWindow::on_radioButton_clicked()
{
    try {
        tabModel->sort(ui->comboBox->currentIndex(), Qt::AscendingOrder); // sort不需要select
    } catch (QException err) {
        qDebug() << err.what();
    }
}

void MainWindow::on_radioButton_2_clicked()
{
    try {
        tabModel->sort(ui->comboBox->currentIndex(), Qt::DescendingOrder); // sort不需要select
    } catch (QException err) {
        qDebug() << err.clone();
    }
}

void MainWindow::on_radioButton_3_clicked()
{
    tabModel->setFilter("name='12'");
    ui->statusbar->showMessage(QString("记录条数为 %1").arg(tabModel->rowCount()));
}

void MainWindow::on_radioButton_4_clicked()
{
    tabModel->setFilter("name='张三'");
    ui->statusbar->showMessage(QString("记录条数为 %1").arg(tabModel->rowCount()));
}

void MainWindow::on_radioButton_5_clicked()
{
    tabModel->setFilter("");
    ui->statusbar->showMessage(QString("记录条数为 %1").arg(tabModel->rowCount()));
}

 mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include "tcomboxdelegate.h"
#include 
#include 
#include 
#include 
#include 
QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACE

class MainWindow : public QMainWindow {
    Q_OBJECT

public:
    MainWindow(QWidget* parent = nullptr);
    ~MainWindow();

private slots:
    void on_pushButton_clicked();
    void do_current_changed(const QModelIndex& current, const QModelIndex& previous);
    void do_current_row_changed(const QModelIndex& current, const QModelIndex& previous);

    void on_pushButton_3_clicked();

    void on_pushButton_2_clicked();

    void on_pushButton_4_clicked();

    void on_pushButton_5_clicked();

    void on_pushButton_6_clicked();

    void on_pushButton_7_clicked();

    void on_pushButton_8_clicked();

    void on_pushButton_9_clicked();

    void on_comboBox_currentIndexChanged(int index);

    void on_radioButton_clicked();

    void on_radioButton_2_clicked();

    void on_radioButton_3_clicked();

    void on_radioButton_4_clicked();

    void on_radioButton_5_clicked();

private:
    Ui::MainWindow* ui;
    QSqlTableModel* tabModel;
    QDataWidgetMapper* dataMapper;
    QItemSelectionModel* selModel;
    QSqlDatabase db;

    TComBoxDelegate delegateSex;
    TComBoxDelegate deleagteDepart;

    void openTable();
};
#endif // MAINWINDOW_H

tcomboxdelegate.cpp

#include "tcomboxdelegate.h"
#include 
TComBoxDelegate::TComBoxDelegate(QObject* parent)
    : QStyledItemDelegate { parent }
{
}
QWidget* TComBoxDelegate::createEditor(QWidget* parent, const QStyleOptionViewItem& option, const QModelIndex& index) const
{
    QComboBox* editor = new QComboBox(parent);
    editor->setEditable(m_editable);
    qDebug() << m_itemList.size();
    for (auto item : m_itemList) {
        editor->addItem(item);
    }
    return editor;
}

void TComBoxDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const
{
    QComboBox* box = dynamic_cast(editor); //把editor转为指向QSpinBox的指针 动态强转
    QString value = index.model()->data(index, Qt::DisplayRole).toString();
    box->setCurrentText(value);
}

void TComBoxDelegate::setModelData(QWidget* editor, QAbstractItemModel* model, const QModelIndex& index) const
{
    QComboBox* box = dynamic_cast(editor); //把editor转为指向QSpinBox的指针 动态强转
    QString value = box->currentText();
    model->setData(index, value);
}

void TComBoxDelegate::updateEditorGeometry(QWidget* editor, const QStyleOptionViewItem& option, const QModelIndex& index) const
{
    editor->setGeometry(option.rect);
}

void TComBoxDelegate::setItems(QStringList list, bool editabale)
{
    m_itemList = list;
    m_editable = editabale;
}

tcomboxdelegate.h

#ifndef TCOMBOXDELEGATE_H
#define TCOMBOXDELEGATE_H

#include 
#include 

class TComBoxDelegate : public QStyledItemDelegate {
    Q_OBJECT
public:
    explicit TComBoxDelegate(QObject* parent = nullptr);

    // QAbstractItemDelegate interface
public:
    virtual QWidget* createEditor(QWidget* parent, const QStyleOptionViewItem& option, const QModelIndex& index) const override;
    virtual void setEditorData(QWidget* editor, const QModelIndex& index) const override;
    virtual void setModelData(QWidget* editor, QAbstractItemModel* model, const QModelIndex& index) const override;
    virtual void updateEditorGeometry(QWidget* editor, const QStyleOptionViewItem& option, const QModelIndex& index) const override;
    void setItems(QStringList list, bool editabale);

private:
    QStringList m_itemList;
    bool m_editable;
};

#endif // TCOMBOXDELEGATE_H

QSqlQueryModel模块使用