关于Qt连接SqLite数据库的一些问题

zero刹那芳华 2017-02-14 12:27:04

第一次运行程序时创建了一个表，然后在这个表中插入了一些数据后
第二次再次运行该程序，可是上次插入的数据却不存在了
这是为什么
该怎么解决

#include <bookshow.h>

#include <QMessageBox>

#include <QHBoxLayout>

#include <QVBoxLayout>

#include <QInputDialog>



BookShow::BookShow(QWidget *parent) :

    QWidget(parent)

{

    if (openDataBase())

    {

        createDataBaseTable();

        QStringList data;

        data << "empty";

        query->exec("select Book_Name from BookInfo");

        while (query->next())

            data << query->value(0).toString();

        model = new QStringListModel(this);

        model->setStringList(data);



        view = new QListView;

        view->setModel(model);



        showButton = new QPushButton("Show", this);

        QObject::connect(showButton, &QPushButton::clicked,

                         this, &BookShow::showDetail);

        deleteButton = new QPushButton("Delete", this);

        QObject::connect(deleteButton, &QPushButton::clicked,

                         this, &BookShow::deleteData);

        insertButton = new QPushButton("Insert", this);

        QObject::connect(insertButton, &QPushButton::clicked,

                         this, &BookShow::insertData);



        QHBoxLayout *buttonLayout = new QHBoxLayout;

        buttonLayout->addWidget(deleteButton);

        buttonLayout->addWidget(showButton);

        buttonLayout->addWidget(insertButton);



        QVBoxLayout *mainLayout = new QVBoxLayout;

        mainLayout->addWidget(view);

        mainLayout->addLayout(buttonLayout);

        setLayout(mainLayout);

    }

}





bool BookShow::openDataBase()

{

    DataBase = QSqlDatabase::addDatabase("QSQLITE");

    DataBase.setHostName("localHost");

    DataBase.setDatabaseName("MyBook");

    DataBase.setUserName("root");

    DataBase.setPassword("123456");

    if (DataBase.open())

    {

        query = new QSqlQuery(DataBase);

        return true;

    }

    QMessageBox::information(this, "error", "The DataBase failed to open!");

    return false;

}



bool BookShow::createDataBaseTable()

{

    QString tableName = "BookInfo";

    query->exec(QString("select * from sys.tables where name = '%1' ").arg(tableName));

    if (!query->next())

        return false;

    query->exec(QString("create table '%1'"

                       "(Book_Name varchar(20),"

                       "Author varchar(10),"

                       "Word_Count int,"

                       "Serial_Status bit").arg(tableName));

    return true;

}



void BookShow::showDetail()

{



}



void BookShow::deleteData()

{



}



void BookShow::insertData()

{

    bool isOk;

    QString text = QInputDialog::getText(this, "Insert",

                                         "Please input new data:",

                                         QLineEdit::Normal,

                                         "you are inserting new data",

                                         &isOk);

    if(isOk)

    {

        QModelIndex currIndex = view->currentIndex();

        model->insertRows(currIndex.row(), 1);

        model->setData(currIndex, text);

        view->edit(currIndex);

        query->exec(QString("insert into BookInfo(Book_Name) values('%1')").arg(text));

    }

}