Qt实现将qsqlite数据库中的数据导出为Excel表格

QT       += core gui sql axcontainer

#ifndef REPORTEXPORTTHREAD_H
#define REPORTEXPORTTHREAD_H

#include <QObject>
#include <QDebug>
#include <QThread>
#include <QFile>
#include <QFileInfo>
#include <QAxObject>
#include <QStandardPaths>
#include <QDir>
#include <QSqlDatabase>
#include <QSqlError>
#include <QSqlQuery>
#include <QSqlRecord>
#include <QThread>
#include <QFileDialog>
class ReportExportThread : public QObject
{
    Q_OBJECT
public:
    typedef enum
    {
        exporting,
        failed,
        finish,
    }ExportState;
signals:
    void export_res_signal(ExportState state,QString info,quint32 totalNum,quint32 exportNum);
public:
    explicit ReportExportThread(QObject *parent = nullptr);

    void export_thread_run(QString dbFile,QString dbTableName,QString xlsxFile);

private:
    void castListListVariant2Variant(const QList<QList<QVariant> > &cells, QVariant &res);
private:
    QAxObject *excel = nullptr;//excel操作对象
    QAxObject *workbooks = nullptr;
    QAxObject* workbook = nullptr; //打开
    QAxObject *activeWorkBook = nullptr;
    QAxObject *worksheet = nullptr; //表单

};

#endif // REPORTEXPORTTHREAD_H

#include "reportExportThread.h"
#include "Windows.h"
ReportExportThread::ReportExportThread(QObject *parent)
    : QObject{parent}
{

}

void ReportExportThread::export_thread_run(QString dbFile, QString dbTableName, QString xlsxFile)
{
    #define SINGLE_OPT_ROW 1000
    QVariant var;
    QVariantList varList;
    QList<QVariant> listVar;
    QList<QList<QVariant> > listListVar;
    quint32 writeRowCnt = 1;//写入起始行计数

    QString range;
    QString cmd;
    QAxObject *writeRange = nullptr;
    quint32 row,col;
    //数据库操作数据
    QSqlDatabase *db = nullptr;
    QSqlDatabase dbA;
    QSqlQuery *query = nullptr;
    QString dbConnectName = "export";

    QAxObject* cellInterior = nullptr;
    QAxObject *font = nullptr;

    QColor bkColor(255, 255, 0 ,50);

    quint32 i,j;

    #define asset_null(a,info)\
    {\
        if(a == nullptr)\
        {\
            emit export_res_signal(failed,info,0,0);\
            goto EXIT;\
        }\
    }\

    qDebug()<<"export_thread_run   "<<QThread::currentThreadId();

    //判断数据库文件是否存在
    QFile dbFiles(dbFile);
    if(!dbFiles.exists())
    {
        emit export_res_signal(failed,tr("数据库文件不存在！"),0,0);
        return;
    }
    dbFiles.close();
    //判断表是否存在
    if(dbTableName.isEmpty())
    {
        emit export_res_signal(failed,tr("数据库表不存在！"),0,0);
        return;
    }
    //判断xlsx文件是否存在
    QFile xlsxFiles(xlsxFile);
    if(!xlsxFiles.exists())
    {
        if(!xlsxFiles.open(QIODevice::WriteOnly))
        {
            emit export_res_signal(failed,tr("xlsx文件创建失败！"),0,0);
            return;
        }
        xlsxFiles.close();
    }
    xlsxFiles.close();
    //判断文件是否为只读
    QFileInfo fileInfo(xlsxFile);
    fileInfo.setFile(fileInfo.filePath()+"/~$"+fileInfo.fileName());
    if(fileInfo.exists())          //判断一下,有没有"~$XXX.xlsx"文件存在,是不是为只读
    {
        emit export_res_signal(failed,tr("xlsx文件为只读文件！"),0,0);
        return;
    }
    fileInfo.setFile(xlsxFile);
    //创建QAxObject对象
    CoInitializeEx(NULL, COINIT_MULTITHREADED);
    this->excel = new QAxObject();//建立excel操作对象

    connect(excel,&QAxObject::exception,this,
            [](int code, const QString &source, const QString &desc, const QString &help)
    {
        qDebug()<<code;
        qDebug()<<source;
        qDebug()<<desc;
        qDebug()<<help;

    });
    this->excel->setControl("Excel.Application");//连接Excel控件
    this->excel->setProperty("Visible", false);//显示窗体看效果
    this->excel->setProperty("DisplayAlerts", false);//显示警告看效果
    this->excel->setProperty("Caption", "Qt Excel");      //标题为Qt Excel
    this->workbooks = excel->querySubObject("WorkBooks");
    this->workbook = workbooks->querySubObject("Open(const QString&)",QDir::toNativeSeparators(fileInfo.absoluteFilePath())); //打开
    this->activeWorkBook = excel->querySubObject("ActiveWorkBook");
    this->worksheet = activeWorkBook->querySubObject("Sheets(int)",1); //获取表单

    //创建QSqlDatabase对象
//    dbA = QSqlDatabase::addDatabase("QSQLITE",dbConnectName);
//    dbA.setDatabaseName("sqltest.db");

    db = new QSqlDatabase(QSqlDatabase::addDatabase("QSQLITE",dbConnectName));
//    db->addDatabase("QSQLITE",dbConnectName);
    db->setDatabaseName(dbFile);
    //打开数据库
//    if(!dbA.open())
//    {
//        emit export_res_signal(failed,tr("数据库打开失败！"),0,0);
//        goto EXIT;
//    }
//    db = &dbA;

    if(!db->open())
    {
        emit export_res_signal(failed,tr("数据库打开失败！"),0,0);
        goto EXIT;
    }

    query = new QSqlQuery(*db);

    //开始设置表头
    cmd =QString("PRAGMA table_info(%1);").arg(dbTableName);
    if(!query->exec(cmd))
    {
        emit export_res_signal(failed,tr("数据库表头操作失败！"),0,0);
        goto EXIT;
    }
    col = query->record().count();      //获取列数
    listVar.clear();
    listListVar.clear();
    while(query->next())
    {
        listVar.append(QVariant(query->value(1).toString()));
        //qDebug()<<query->value(1).toString();
    }
    listListVar.append(listVar);

    this->castListListVariant2Variant(listListVar,var);
    range = QString("A1:%1%2").arg(QChar('A'+col-1)).arg(writeRowCnt++);
    //qDebug()<<range;
    writeRange = this->worksheet->querySubObject("Range(const QString&)",range);
    asset_null(writeRange,tr("Excel打开失败！"));
    writeRange->dynamicCall("Value", var);
    //开始设置表头背景颜色
    cellInterior = writeRange->querySubObject("Interior");
    asset_null(cellInterior,tr("Excel打开失败！"));
    cellInterior->setProperty("Color", bkColor);

    //开始调整背景字体
    font = writeRange->querySubObject("Font");  //获取单元格字体
    asset_null(font,tr("Excel打开失败！"));
    font->setProperty("Bold", true);  //字体加粗
    font->setProperty("Color", QColor(255, 0, 0));  //设置单元格字体颜色（红色）
    delete writeRange;

    //获取数据行数
    cmd =QString("SELECT count(*) FROM %1;").arg(dbTableName);
    if(!query->exec(cmd))
    {
        emit export_res_signal(failed,tr("数据库行数获取失败！"),0,0);
        goto EXIT;
    }
    query->next();
    row = query->value(0).toInt();
    //开始导出数据
    for(i =0;i < row; i+=SINGLE_OPT_ROW)
    {
        listListVar.clear();

        query->clear();
        cmd =QString("select * from %1 limit %2,%3").arg(dbTableName).arg(i).arg(SINGLE_OPT_ROW);
        //qDebug()<<cmd;
        if(!query->exec(cmd))
        {
            emit export_res_signal(failed,tr("数据库数据获取失败！"),0,0);
            goto EXIT;
        }
        //读取数据
        int dataRowCnt = 0;
        while(query->next())
        {
            listVar.clear();
            for(j=0;j<col;j++)
            {
                listVar.append(query->value(j));
            }
            listListVar.append(listVar);
            dataRowCnt++;
        }
        //写入数据
        this->castListListVariant2Variant(listListVar,var);
        range = QString("A%1:%2%3").arg(writeRowCnt).arg(QChar('A'+col-1)).arg(dataRowCnt+writeRowCnt-1);
        //qDebug()<<range;
        writeRange = this->worksheet->querySubObject("Range(const QString&)",range);
        asset_null(writeRange,tr("Excel打开失败！"));
        writeRange->dynamicCall("Value", var);

        writeRowCnt+=dataRowCnt;

        delete writeRange;
        emit export_res_signal(exporting,tr("数据正在导出！"),row,writeRowCnt-2);
    }



    emit export_res_signal(finish,tr("数据导出成功！"),row,row);

    EXIT:

    if(this->excel != nullptr)
    {
        this->workbook->dynamicCall("Save()" );
        this->workbook->dynamicCall("Close()");  //关闭文件
        this->excel->dynamicCall("Quit()");//关闭excel

        delete excel;
        excel = nullptr;
    }
    if(query != nullptr)
    {
        delete query;
        query = nullptr;
    }
    if(db->isOpen())
    {
        db->close();
        delete db;
        QSqlDatabase::removeDatabase(dbConnectName);
    }
}

void ReportExportThread::castListListVariant2Variant(const QList<QList<QVariant> > &cells, QVariant &res)
{
    QVariantList vars;
    const int rows = cells.size();
    for(int i=0;i<rows;++i)
    {
        vars.append(QVariant(cells[i]));
    }
    res = QVariant(vars);
}

	reportExportThread->start();
    QString savePath = QFileDialog::getExistingDirectory(this,"请选择导入的文件夹！",
                                                         "",
                                                         QFileDialog::ShowDirsOnly);


    emit start_export_thread("sqltest.db","produceTable",savePath+"/"+QDateTime::currentDateTime().toString("yyyy_MM_dd_hh_mm_ss")+".xlsx");