QT----DAtABASE QMYSL驅動 QSqlDatabase: QMYSQL driver not loaded

HEADERS += \

    Widget01.h \

    Widget02.h \

    Widget03.h \

    Widget04.h \

    Contact.h \

    Widget05.h

SOURCES += \

    Widget01.cpp \

    main.cpp \

    Widget02.cpp \

    Widget03.cpp \

    Widget04.cpp \

    Contact.cpp \

    Widget05.cpp

QT += gui widgets sql

CONFIG += C++11

#ifndef CONTACT_H

#define CONTACT_H

#include <QWidget>

#include <QSqlTableModel>

#include <QTableView>

#include <QLineEdit>

#include <QPushButton>

class Contact : public QWidget

{

    Q_OBJECT

public:

    explicit Contact(QWidget *parent = 0);

    QSqlTableModel* _model;

    QTableView* _view;

    QLineEdit* _filter;

    QPushButton* _add;

    QPushButton* _del;

    QPushButton* _reset;

    QPushButton* _submit;

signals:

public slots:

    void slotModelDataChanged(QModelIndex,QModelIndex);

    void slotFilterChanged(QString filter);

};

#endif // CONTACT_H

CONTACT.cpp

#include "Contact.h"

#include <QVBoxLayout>

#include <QHBoxLayout>

#include <QSqlRecord>

#include <QCompleter>

#include <QDebug>

Contact::Contact(QWidget *parent) :

    QWidget(parent)

{

    _model = new QSqlTableModel;

    _view = new QTableView;

    _view->setModel(_model);

    _model->setTable("tcontact");

    _model->setEditStrategy(QSqlTableModel::OnManualSubmit);

    connect(_model, SIGNAL(dataChanged(QModelIndex,QModelIndex)),

            this, SLOT(slotModelDataChanged(QModelIndex,QModelIndex)));

    _model->select();

    // set Layout

    QVBoxLayout* vBox = new QVBoxLayout(this);

    vBox->addWidget(_view);

    QHBoxLayout* hBox = new QHBoxLayout;

    vBox->addLayout(hBox);

    hBox->addWidget(_filter = new QLineEdit, 1);

    hBox->addWidget(_add=new QPushButton("Add"));

    hBox->addWidget(_del=new QPushButton("Del"));

    hBox->addWidget(_reset=new QPushButton("Reset"));

    hBox->addWidget(_submit=new QPushButton("Submit"));

    connect(_add, &QPushButton::clicked, [&](){

        QSqlRecord record = _model->record();

        _model->insertRecord(-1, record);

    });

    connect(_del, &QPushButton::clicked, [&](){});

    connect(_reset, &QPushButton::clicked, [&](){});

    connect(_submit, &QPushButton::clicked, [&](){

        _model->submitAll();

    });

    connect(_filter, SIGNAL(textChanged(QString)),

            this, SLOT(slotFilterChanged(QString)));

    slotModelDataChanged(QModelIndex(), QModelIndex());

}

void Contact::slotFilterChanged(QString filter)

{

    if(filter.isEmpty())

    {

        _model->setFilter("");

        _model->select();

        return;

    }

 //  username like filter or password like  filter .......

    QSqlRecord record = _model->record();

    QString modelFilter;

    for(int i=0; i<record.count(); ++i)

    {

        if(i!=0)

        {

            modelFilter += " or ";

        }

        QString field = record.fieldName(i);

        QString subFilter = QString().sprintf("%s like '%%%s%%'", field.toUtf8().data(), filter.toUtf8().data());

      //  qDebug() << subFilter;

        modelFilter += subFilter;

    }

    qDebug() << modelFilter;

    _model->setFilter(modelFilter);

    _model->select();

}

void Contact::slotModelDataChanged(QModelIndex,QModelIndex)

{

    QStringList strList;

    for(int i=0; i<_model->rowCount(); ++i)

    {

        QSqlRecord record = _model->record(i);

        for(int j=0; j<record.count(); ++j)

        {

            QVariant var = record.value(j);

            if(var.isNull()) continue;

            strList << var.toString();

        }

    }

    qDebug() << strList;

    QCompleter* completer=new QCompleter(strList);

    _filter->setCompleter(completer);

}

#ifndef WIDGET01_H

#define WIDGET01_H

#include <QWidget>

class Widget01 : public QWidget

{

    Q_OBJECT

public:

    explicit Widget01(QWidget *parent = 0);

signals:

public slots:

};

#endif // WIDGET01_H

Widget01.cpp

#include "Widget01.h"

#include <QSqlDatabase>

#include <QSqlError>

#include <QSqlQuery>

#include <QSqlResult>

#include <QDebug>

Widget01::Widget01(QWidget *parent) :

    QWidget(parent)

{

    /* QSQLITE QODBC QPLSQL */

    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");

    db.setHostName("127.0.0.1");

    db.setUserName("root");

    db.setPassword("iamxgl");

    db.setDatabaseName("d0718");

    bool bRet = db.open();

    if(bRet == false)

    {

        qDebug() << "error open database" << db.lastError().text();

        exit(0);

    }

    qDebug() << "open database success";

 //   db.exec("insert into tuser (username, password, gender) values('xueguoliang', 'xxdfsdf', 1)");

    QSqlQuery query = db.exec("select * from d0718");

   // int size = query.size();

    bool b = query.first();

    while(b)

    {

 //       QSqlResult* result = query.result();

  //      QVector<QVariant> values =  result->boundValues();

     //   qDebug() << values;

        b = query.next();

    }

}

#ifndef WIDGET02_H

#define WIDGET02_H

#include <QWidget>

class Widget02 : public QWidget

{

    Q_OBJECT

public:

    explicit Widget02(QWidget *parent = 0);

signals:

public slots:

};

#endif // WIDGET02_H

Widget02.cpp

#include "Widget02.h"

#include <QSqlDatabase>

#include <QSqlTableModel>

#include <QSqlRecord>

#include <QDebug>

#include <QSqlError>

Widget02::Widget02(QWidget *parent) :

    QWidget(parent)

{

    // QSqlTableModel: 數據表對應的數據結構

    QSqlTableModel model;

    model.setTable("tuser");

    //model.setFilter("username<>'newuser'");

    model.select();  // exec query

    int ret = model.rowCount();

    // read data from database

    for(int i=0; i<ret; ++i)

    {

       QSqlRecord record = model.record(i);

       for(int j=0; j<record.count(); j++)

       {

           qDebug() << record.value(j);

       }

    }

    // update data to database

 //   model.setData(model.index(0, 1), "xxxxxx");

  //  model.submitAll();

    // insert data to database

    QSqlRecord record = model.record();

//    record.setValue("id", );

    record.setValue("username", "newuser1");

    record.setValue("password", "newpassword");

    record.setValue("gender", 1);

    model.insertRecord(-1, record);

    model.submitAll();

}

#ifndef WIDGET03_H

#define WIDGET03_H

#include <QObject>

#include <QSqlTableModel>

#include <QTableView> // show table

class Widget03 : public QWidget

{

    Q_OBJECT

public:

    explicit Widget03(QWidget *parent = 0);

    QSqlTableModel* _model;

    QTableView* _view;

signals:

public slots:

    void slotSubmitClicked();

    void slotDelClicked();

    void slotAddClicked();

};

#endif // WIDGET03_H

Widget03.cpp

#include "Widget03.h"

#include <QVBoxLayout>

#include <QHBoxLayout>

#include <QPushButton>

#include <QMessageBox>

#include <QSqlError>

#include <QSqlDatabase>

#include <QSqlRecord>

Widget03::Widget03(QWidget *parent) :

    QWidget(parent)

{

    _model = new QSqlTableModel;

    _model->setTable("tuser");

    _model->select();

   _model->setEditStrategy(QSqlTableModel::OnManualSubmit);

    _model->setHeaderData(0, Qt::Horizontal, "編號");

    _model->setHeaderData(1, Qt::Horizontal, "用戶名");

    _model->setHeaderData(2, Qt::Horizontal, "密碼");

    _model->setHeaderData(3, Qt::Horizontal, "性別");

    _view = new QTableView;

    _view->setModel(_model);

//    _view->hideColumn(2);

    QVBoxLayout* lay = new QVBoxLayout(this);

    lay->addWidget(_view);

    QHBoxLayout* hBox = new QHBoxLayout;

    lay->addLayout(hBox);

    hBox->addStretch();

    QPushButton* del = new QPushButton("del");

    connect(del, SIGNAL(clicked()), this, SLOT(slotDelClicked()));

    hBox->addWidget(del);

    QPushButton* submit = new QPushButton("submit");

    connect(submit, SIGNAL(clicked()), this, SLOT(slotSubmitClicked()));

    hBox->addWidget(submit);

    QPushButton* add = new QPushButton("add");

    connect(add, SIGNAL(clicked()), this, SLOT(slotAddClicked()));

    hBox->addWidget(add);

}

void Widget03::slotAddClicked()

{

    // start transaction

    _model->database().transaction();

    QSqlRecord record = _model->record();

    _model->insertRecord(-1, record);

}

void Widget03::slotDelClicked()

{

    // 通過_view去獲取被選中的部分的數據model

    QItemSelectionModel * selectModel = _view->selectionModel();

// 通過選中的數據結構，獲取這些格子的ModelIndex

    QModelIndexList selectList =  selectModel->selectedIndexes();

    QList<int> delRow;

    // 遍歷這些格子，獲取格子所在行，因爲可能存在相同的行，所以要去重

    for(int i=0; i<selectList.size(); ++i)

    {

        QModelIndex index = selectList.at(i);

      //  _model->removeRow(index.row());

        delRow << index.row();

    }

    while(delRow.size() > 0)

    {

        int row = delRow.at(0);

        delRow.removeAll(row);

        _model->removeRow(row);

    }

    _model->submitAll();

}

void Widget03::slotSubmitClicked()

{

    if(!_model->submitAll())

    {

        QMessageBox::critical(this, "Error", QSqlDatabase().lastError().text());

        _model->database().rollback();

    }

    else

    {

        _model->database().commit();

    }

}

#ifndef WIDGET04_H

#define WIDGET04_H

#include <QObject>

#include <QSqlTableModel>

#include <QTableView> // show table

#include <QItemDelegate>

#include <QComboBox>

class TUserDelegate : public QItemDelegate

{

    QWidget *createEditor(QWidget * parent,

                          const QStyleOptionViewItem &option,

                          const QModelIndex &index) const

    {

        if(index.column() == 0)

            return NULL;

        if(index.column() == 3)

        {

            QComboBox*  combo = new QComboBox(parent);

            combo->addItem("男");

            combo->addItem("女");

            return combo;

        }

        return QItemDelegate::createEditor(parent, option, index);

    }

};

#if 0

class ReadOnlyDelegate : public QItemDelegate

{

    QWidget *createEditor(QWidget *,

                          const QStyleOptionViewItem &,

                          const QModelIndex &) const

    {

        return NULL;

    }

};

class GenderDelegate : public QItemDelegate

{

public:

    QWidget *createEditor(QWidget *parent,

                          const QStyleOptionViewItem &,

                          const QModelIndex &) const

    {

        QComboBox*  combo = new QComboBox(parent);

        combo->addItem("男");

        combo->addItem("女");

        return combo;

    }

};

#endif

class MyTableModel : public QSqlTableModel

{

public:

    QVariant data(const QModelIndex &idx, int role = Qt::DisplayRole) const

    {

     //   if(role == Qt::DisplayRole)

     //       return QSqlTableModel::data(idx, role);

        if(idx.column() != 3)

            return QSqlTableModel::data(idx, role);

        QVariant var = QSqlTableModel::data(idx, role);

        if(var == 0)

        {

            return "女";

        }

        return "男";

    }

    bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole)

    {

        if(index.column() != 3)

            return QSqlTableModel::setData(index, value, role);

        if(value == "男")

            return QSqlTableModel::setData(index, 1, role);

        return QSqlTableModel::setData(index, 0, role);

    }

};

class Widget04 : public QWidget

{

    Q_OBJECT

public:

    explicit Widget04(QWidget *parent = 0);

    MyTableModel* _model;

    QTableView* _view;

signals:

public slots:

    void slotSubmitClicked();

    void slotDelClicked();

    void slotAddClicked();

};

#endif // WIDGET04_H

Widget04.cpp

#include "Widget04.h"

#include <QVBoxLayout>

#include <QHBoxLayout>

#include <QPushButton>

#include <QMessageBox>

#include <QSqlError>

#include <QSqlDatabase>

#include <QSqlRecord>

Widget04::Widget04(QWidget *parent) :

    QWidget(parent)

{

    _model = new MyTableModel;

    _model->setTable("tuser");

    _model->select();

   _model->setEditStrategy(QSqlTableModel::OnManualSubmit);

    _model->setHeaderData(0, Qt::Horizontal, "編號");

    _model->setHeaderData(1, Qt::Horizontal, "用戶名");

    _model->setHeaderData(2, Qt::Horizontal, "密碼");

    _model->setHeaderData(3, Qt::Horizontal, "性別");

    _view = new QTableView;

    _view->setModel(_model);

//    _view->hideColumn(2);

  //  _view->setItemDelegateForColumn(3, new GenderDelegate);

   // _view->setItemDelegateForColumn(0, new ReadOnlyDelegate);

    _view->setItemDelegate(new TUserDelegate);

    QVBoxLayout* lay = new QVBoxLayout(this);

    lay->addWidget(_view);

    QHBoxLayout* hBox = new QHBoxLayout;

    lay->addLayout(hBox);

    hBox->addStretch();

    QPushButton* del = new QPushButton("del");

    connect(del, SIGNAL(clicked()), this, SLOT(slotDelClicked()));

    hBox->addWidget(del);

    QPushButton* submit = new QPushButton("submit");

    connect(submit, SIGNAL(clicked()), this, SLOT(slotSubmitClicked()));

    hBox->addWidget(submit);

    QPushButton* add = new QPushButton("add");

    connect(add, SIGNAL(clicked()), this, SLOT(slotAddClicked()));

    hBox->addWidget(add);

}

void Widget04::slotAddClicked()

{

    QSqlRecord record = _model->record();

    _model->insertRecord(-1, record);

}

void Widget04::slotDelClicked()

{

    // 通過_view去獲取被選中的部分的數據model

    QItemSelectionModel * selectModel = _view->selectionModel();

// 通過選中的數據結構，獲取這些格子的ModelIndex

    QModelIndexList selectList =  selectModel->selectedIndexes();

    QList<int> delRow;

    // 遍歷這些格子，獲取格子所在行，因爲可能存在相同的行，所以要去重

    for(int i=0; i<selectList.size(); ++i)

    {

        QModelIndex index = selectList.at(i);

      //  _model->removeRow(index.row());

        delRow << index.row();

    }

    while(delRow.size() > 0)

    {

        int row = delRow.at(0);

        delRow.removeAll(row);

        _model->removeRow(row);

    }

    _model->submitAll();

}

void Widget04::slotSubmitClicked()

{

    if(!_model->submitAll())

    {

        QMessageBox::critical(this, "Error", QSqlDatabase().lastError().text());

    }

}

#ifndef WIDGET05_H

#define WIDGET05_H

#include <QWidget>

#include <QSqlQueryModel>

#include <QTableView>

class Widget05 : public QWidget

{

    Q_OBJECT

public:

    explicit Widget05(QWidget *parent = 0);

    QSqlQueryModel* _model;

    QTableView *_view;

signals:

public slots:

};

#endif // WIDGET05_H

Widget05.cpp

#include "Widget05.h"

#include <QSqlQuery>

#include <QVBoxLayout>

Widget05::Widget05(QWidget *parent) :

    QWidget(parent)

{

    _model = new QSqlQueryModel;

    _view = new QTableView(this);

    _view->setModel(_model);

    _model->setQuery("select * from tuser");

    _model->query();

    QVBoxLayout* lay = new QVBoxLayout(this);

    lay->addWidget(_view);

}

main.cpp

#include <QApplication>

#include "Widget05.h"

#include <QSqlDatabase>

#include <QSqlError>

#include <QDebug>

#include "Contact.h"

int main(int argc, char*argv[])

{

    QApplication app(argc, argv);

    /* QSQLITE QODBC QPLSQL */

    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");

    db.setHostName("127.0.0.1");

    db.setUserName("root");

    db.setPassword("iamxgl");

    db.setDatabaseName("d0718");

    bool bRet = db.open();

    if(bRet == false)

    {

        qDebug() << "error open database" << db.lastError().text();

        exit(0);

    }

    qDebug() << "open database success";

    Widget05 w;

    w.show();

    return app.exec();

}

使用如下方法進行解決：L::

QSqlDatabase: QMYSQL driver not loaded

QSqlDatabase: available drivers: QSQLITE QODBC QODBC3

 

Qt5.0開源版本默認是不提供QMySQL驅動的，這篇文檔主要講述Windows環境下如何使用MinGW爲Qt5.0安裝QMySQL驅動。

 

(1) 安裝Qt5.0開源版本的library和source code：

Qt5.0 Library: http://download.qt-project.org/official_releases/qt/5.0/5.0.2/qt-windows-opensource-5.0.2-mingw47_32-x86-offline.exe

Qt5.0 Source Code: http://download.qt-project.org/official_releases/qt/5.0/5.0.2/single/qt-everywhere-opensource-src-5.0.2.zip

 

(2) 安裝MySQL Installer 5.6.11:

MySQL Installer 5.6.11: http://dev.mysql.com/downloads/installer/

將MySQL安裝在C盤自建目錄MySQL中，儘量不使用Program files目錄(空格)可能引起莫名的路徑問題。

 

(3) 打開Qt5.0命令行界面:

啓動方式：開始菜單=>>所有程序==>>Qt5.0.2==>>Qt5.0.2==>>MinGW 4.7==>>Qt 5.0.2 for Desktop (MinGW 4.7)

 

(4) 運行以下命令：

這是最重要的一步，確保Source Code和MySQL安裝在同一個盤符。

cd C:\Qt\Qt5.0.1\Sources\qtbase\src\plugins\sqldrivers\mysql\

該目錄下存在幾個文件，其中包括mysql.pro，我們所有的編譯工作也正是從此文件開始。

qmake "INCLUDEPATH+=c:\\MySQL\\include" "LIBS+=c:\\MySQL\\lib\\libmysql.lib" -o Makefile mysql.pro

此時，會在當前目錄下生成幾個Makefile文件和兩個文件夾類。

 

此處我們也可將mysql的兩路徑：

INCLUDEPATH += "C:/MySQL/include"

LIBS += "C:/MySQL/lib/libmysql.lib"

直接加入mysql.pro中，然後運行qmake命令如下：

qmake -o Makefile mysql.pro

 

最後運行：

mingw32-make

如果一切順利，此時在C:\Qt\Qt5.0.1\Sources\qtbase\plugins\sqldrivers會生成qsqlmysql.dll和qsqlmysqld.dll文件。

 

(5) 配置QMySQL驅動：

拷貝qsqlmysql.dll和qsqlmysqld.dll到C:\Qt\Qt5.0.1\5.0.1\mingw47_32\plugins\sqldrivers目錄中

從c:\MySQL\lib拷貝libmysql.dll到C:\Qt\Qt5.0.2\5.0.2\mingw47_32\bin，此時大功告成。

 

(6) 測試QMYSQL驅動：

#include <QApplication>

#include <QtSql>

#include <QtWidgets>

#include <iostream>

 

bool createConnection()

{

    QSqlDatabase db=QSqlDatabase::addDatabase("QMYSQL");

    db.setHostName("localhost");

    db.setDatabaseName("test");

    db.setUserName("root");

    db.setPassword("123456");

    if(!db.open()) {

        QMessageBox::critical(0, QObject::tr("Database Error"), \

            db.lastError().text());

        return false;

    }

    return true;

}

 

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    if(!createConnection())

        return 1;

    QSqlQuery query("SELECT title, year FROM cd WHERE year >= 1930");

    while(query.next()) {

        QString title=query.value(0).toString();

        int year=query.value(1).toInt()

        std::cerr<<qPrintable(title)<<": "<<year<<std::endl;

    }

    return a.exec();

}

 

E:\QT\chap13\build-QMysqlTest-Desktop_Qt_5_0_2_MinGW_32bit-Debug\debug\QMysqlTest 啓動中...

你好: 1983

周杰倫: 1956

薩頂頂: 1957

 

(7) 好吧，如果你仍然沒有成功，可在此直接下載MySQL用於以下Qt版本的驅動：

Qt5.0版本: http://vdisk.weibo.com/s/aMEiEcvN1JUJH

Qt5.1版本: http://vdisk.weibo.com/s/aMEiEcvN1JUJR

 

雖然版本不一樣，但是編譯MySQL驅動的方法都遵循以上步驟，最後祝你好運。